JP2012183915A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more properly suppress fuel consumption due to operation of an internal combustion engine.SOLUTION: When forced charging travel control is started (time t1) which controls to travel by requested torque Tr* while charging a battery by electric power from a first motor by continuing operation of the engine as a control energy storage rate SOCc of the battery becomes a charging necessary threshold Smin or less, at the time (time t2) of excessive estimated drop time when the control energy storage rate SOCc is dropped from a state where the rate is larger than an actual energy storage rate SOC, exceeding a permissible range, and is equal to or less than a charging required threshold Smin, the forced charging travel control is continued (time t3) until the control energy storage rate SOCc becomes larger than the charging necessary threshold Smin and reaches a second threshold S2 smaller than the first threshold S1. Thereby, with timing when a smaller control energy storage rate SOCc is reached during the excessive estimated drop, the forced charging travel control is completed, and useless fuel consumption due to operation of the engine is suppressed.

Description

  The present invention relates to a hybrid vehicle, and more particularly, to an internal combustion engine, a generator capable of generating electric power using power from the internal combustion engine, an electric motor capable of inputting / outputting driving power, and exchange of electric power with the generator and the electric motor. A rechargeable battery, an estimated power storage ratio calculating means for calculating an estimated power storage ratio as an estimated value of the power storage ratio, which is a ratio of the amount of power stored in the secondary battery to the total capacity, and the calculated estimated power storage ratio When the internal combustion engine falls below a predetermined charging threshold value, the internal combustion engine is continuously operated to charge the secondary battery with the electric power from the generator and to generate the required driving force required for traveling. The present invention relates to a hybrid vehicle including control means for performing forced charging traveling control for controlling a motor and an electric motor.

  Conventionally, this type of hybrid vehicle includes an engine, a motor generator, a power split mechanism connected to the engine, the motor generator, and the drive wheel side, an electric motor connected to the drive wheel side, a motor generator, and an electric motor. There has been proposed a battery that includes a battery connected to a motor and travels while prohibiting stop of idle operation of the engine (see, for example, Patent Document 1). In this hybrid vehicle, the engine stop time is controlled by, for example, controlling so that the time during which the engine idling is stopped is increased as the temperature of the battery increases.

JP 2004-60526 A

  By the way, in the hybrid vehicle having the hardware configuration described above, when the battery storage ratio (SOC) drops below a threshold value, the engine operation is prohibited and the operation is forcibly continued to recover the storage ratio. Therefore, forced charging control is performed to charge the battery with the power generated by the generator. However, forced charging due to factors such as battery management despite the fact that the vehicle's actual driving tendency, such as road congestion and the driving tendency of the driver, can recover the power storage ratio. In some cases, the control is started, and the engine operation continues unnecessarily.

  The main purpose of the hybrid vehicle of the present invention is to more appropriately suppress fuel consumption due to operation of the internal combustion engine.

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

The hybrid vehicle of the present invention
An internal combustion engine, a generator capable of generating electric power using power from the internal combustion engine, an electric motor capable of inputting and outputting power for traveling, a secondary battery capable of exchanging electric power with the generator and the electric motor, An estimated power storage ratio calculating means for calculating an estimated power storage ratio as an estimated value of a power storage ratio that is a ratio of the power storage amount stored in the secondary battery to the total capacity based on the state of the secondary battery; Until the estimated power storage ratio falls below a predetermined charging threshold, the secondary battery is charged with charging power that tends to increase as the estimated power storage ratio decreases when the internal combustion engine is operated. The internal combustion engine, the generator, and the electric motor are controlled to travel with a required driving force required for traveling with intermittent operation, and the calculated estimated power storage ratio is less than or equal to the required charging threshold. When the internal combustion engine continues to operate, the secondary battery is charged with the electric power from the generator, and the internal combustion engine, the generator, and the electric motor are controlled to run with the required driving force. A hybrid vehicle comprising control means for performing charge travel control,
When the control means starts the forced charging travel control, the estimated power storage ratio is decreased from a state where the estimated power storage ratio exceeds the allowable power storage ratio beyond the actual power storage ratio of the secondary battery, and the calculated estimated power storage ratio is When it is not at the time of an excessive estimation decrease that has become equal to or less than the required charging threshold, the forced charging traveling control is performed until the calculated estimated power storage ratio reaches a first charging end threshold that is predetermined as a value that is greater than the required charging threshold. If the overestimated reduction is continued, the forced charge running control is performed until the calculated estimated power storage ratio reaches a second charge end threshold value that is greater than the charge required threshold value and smaller than the first charge end threshold value. This is a means to continue

  In the hybrid vehicle of the present invention, the estimated power storage ratio is calculated as an estimated value of the power storage ratio that is the ratio of the power storage amount stored in the secondary battery to the total capacity. Then, when the calculated estimated power storage ratio becomes equal to or lower than the charging required threshold value, the internal combustion engine is continuously operated to charge the secondary battery with the electric power from the generator and to travel with the required driving force required for traveling. When the forced charge running control for controlling the internal combustion engine, the generator, and the motor is started, the estimated power storage ratio is calculated by being reduced from a larger state than the actual power storage ratio of the secondary battery exceeding the allowable range. When there is no overestimated decline when the power storage ratio is equal to or lower than a predetermined charge required threshold, forced charging is performed until the calculated estimated power storage ratio is greater than the charge required threshold and reaches a first charge end threshold determined in advance. Continue running control. In addition, when the excessive charge is reduced when the forced charge running control is started, the forced charge is calculated until the calculated estimated power storage ratio becomes a second charge end threshold value that is larger than the charge necessary threshold value and smaller than the first charge end threshold value. Continue charging control. In other words, when the forced charge traveling control is started, when the overestimation is reduced, the forced charge traveling control is terminated at a timing when the estimated power storage ratio becomes a smaller threshold than when the overestimation is not reduced. As a result, fuel consumption due to operation of the internal combustion engine can be suppressed at the time of an excessive estimation decrease. In addition, at the time of overestimation decline, the estimated power storage ratio was larger than the actual power storage ratio beyond the allowable range, so the charging of the secondary battery was suppressed due to an error included in the estimated power storage ratio. It can be said that it was in a state. Therefore, it can be said that there is room for recovering the power storage ratio of the secondary battery when the estimated power storage ratio can be made closer to the actual power storage ratio at the time of excessive estimation decrease. Therefore, when the forced charge traveling control is started, when it is at the time of excessive estimation decrease, it can be said that it is less necessary to restore the power storage ratio by forced charging traveling control than when it is not at the time of excessive estimation decrease. Since the forced charging travel control is terminated at a timing when the estimated power storage ratio becomes smaller at the time of such an excessive estimation decrease, fuel consumption due to operation of the internal combustion engine can be more appropriately suppressed.

  In such a hybrid vehicle of the present invention, the secondary battery has a power storage ratio that is higher when the voltage of the secondary battery is within a predetermined voltage range including at least a predetermined low voltage range than when the voltage is outside the predetermined voltage range. A battery characteristic in which a change amount of the voltage of the secondary battery with respect to a unit change amount is increased, and the estimated storage ratio calculation means is configured to determine the storage ratio based on an integrated value of a current for charging and discharging the secondary battery. And calculating a cumulative power storage ratio that is an estimated value of 1, and using a predetermined relationship between the power storage ratio and the voltage of the secondary battery reflecting the battery characteristics based on the voltage of the secondary battery A voltage storage ratio that is a second estimated value of the storage ratio is set, and when the voltage of the secondary battery is outside the predetermined voltage range, the calculated integrated storage ratio is more than the set voltage storage ratio. The estimated power storage ratio is calculated to be a close value, and when the voltage of the secondary battery is within the predetermined voltage range, the set voltage storage ratio is increased as the voltage of the secondary battery is separated from outside the predetermined voltage range. A means for calculating the estimated power storage ratio so as to become a close tendency value, wherein the control means calculates the calculated power storage ratio when the forced charge travel control is started. Further, it may be a means for controlling the time when the ratio is smaller than a predetermined ratio more than a predetermined time as the overestimation reduction time. If it carries out like this, it can be discriminate | determined whether it is at the time of an overestimation fall by comparison with an estimated electrical storage ratio and an integral electrical storage ratio. Here, as the “secondary battery”, a nickel-hydrogen secondary battery or the like can be used. In this case, the estimated power storage ratio calculating means uses the calculated integrated power storage ratio as the estimated power storage ratio when the voltage of the secondary battery is outside the predetermined voltage range, and the voltage of the secondary battery is When the voltage is within the predetermined voltage range, the secondary battery voltage may be a means that uses a value that becomes closer to the set voltage storage ratio as the voltage goes away from the predetermined voltage range as the estimated power storage ratio.

  Further, in the hybrid vehicle of the present invention, the secondary battery has the power storage ratio when the power storage ratio is within a predetermined power storage ratio range including at least a predetermined low power storage ratio range than when it is outside the predetermined power storage ratio range. A battery characteristic in which a change amount of the voltage of the secondary battery with respect to a unit change amount of the battery is large, and the estimated storage ratio calculation means calculates the storage ratio based on an integrated value of a current for charging and discharging the secondary battery. While calculating a cumulative power storage ratio that is a first estimated value, a predetermined relationship between the voltage of the secondary battery and the power storage ratio reflecting the battery characteristics based on the voltage of the secondary battery is used. A voltage storage ratio that is a second estimated value of the storage ratio, and when the calculated integrated storage ratio is outside the predetermined storage ratio range, the calculated product is greater than the set voltage storage ratio. A value closer to the power storage ratio is calculated as the estimated power storage ratio, and when the calculated cumulative power storage ratio is within the predetermined power storage ratio range, the set voltage storage is set such that the calculated cumulative power storage ratio is farther from the outside of the predetermined power storage ratio range. A means for calculating a value of a tendency close to a ratio as the estimated power storage ratio, wherein the control means calculates the estimated power storage ratio when starting the forced charging travel control from the calculated cumulative power storage ratio. It may be a means for controlling the time when it is smaller than a predetermined ratio as a time when the overestimation is reduced. If it carries out like this, it can be discriminate | determined whether it is at the time of an overestimation fall by comparison with an estimated electrical storage ratio and an integral electrical storage ratio. Here, as the “secondary battery”, a nickel-hydrogen secondary battery or the like can be used. The “low power storage ratio range” can be a range including a charging necessary threshold value. In this case, the estimated power storage ratio calculating means uses the calculated integrated power storage ratio as the estimated power storage ratio when the calculated integrated power storage ratio is outside the predetermined power storage ratio range, and the calculated integrated power storage ratio is When the value is within the predetermined power storage ratio range, the estimated power storage ratio may be a means that uses a value that becomes closer to the set voltage power storage ratio as the calculated cumulative power storage ratio becomes far from the predetermined power storage ratio range. it can.

  In the hybrid vehicle of the present invention that controls when the estimated power storage ratio is smaller than the cumulative power storage ratio by a predetermined ratio or more as the time of overestimation reduction, the estimated power storage ratio calculation means is configured to start the forced charging travel control when the forced charging travel control starts. It is also possible to replace the integrated power storage ratio with a value equal to the estimated power storage ratio. If it carries out like this, an integrated electrical storage ratio can be made into a value closer to the actual electrical storage ratio of a secondary battery after starting forced charge travel control.

  Further, in the hybrid vehicle of the present invention, when the control means starts the forced charging travel control with the start of the internal combustion engine while traveling with the operation of the internal combustion engine stopped, It may be a means for controlling the internal combustion engine so that the operation of the internal combustion engine is stopped when the operation of the internal combustion engine is not requested when the forced charging traveling control is terminated.

  Alternatively, in the hybrid vehicle of the present invention, a planet in which three rotating elements are connected to three axes of an output shaft of the internal combustion engine, a rotating shaft of the generator, and a driving shaft connected to the electric motor. It can also be provided with a gear mechanism.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. 4 is a flowchart showing an example of a drive control routine executed by a hybrid electronic control unit 70. It is explanatory drawing which shows an example of the map for charging / discharging request | requirement power setting. 5 is a flowchart illustrating an example of a power storage ratio setting routine executed by a battery ECU 52. It is explanatory drawing which shows an example of the characteristic of the battery 50 represented as a relationship between the electrical storage ratio SOC of the battery 50, and the battery voltage Vb. It is explanatory drawing which shows an example of the reflection coefficient setting map for setting the control electrical storage ratio SOCc of the battery. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the collinear diagram which shows the dynamic relationship between the rotation speed and torque in the rotation element of the power distribution integration mechanism 30 when drive | working in motor operation mode. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, the target rotational speed Ne *, and the target torque Te * are set. It is explanatory drawing which shows an example of the collinear diagram which shows the dynamic relationship between the rotation speed and torque in the rotation element of the power distribution integration mechanism 30 when drive | working by engine operation mode. 5 is a flowchart showing an example of a forced charging related setting routine executed by a hybrid electronic control unit 70. It is explanatory drawing which shows an example of the mode of the time change of the control electrical storage ratio SOCc of battery 50, deviation (DELTA) SOC, its state, and the forced charge request flag Fb. It is explanatory drawing which shows an example of the reflection coefficient setting map of a modification. It is a flowchart which shows an example of the electrical storage ratio setting routine performed by battery ECU52 of a modification. It is explanatory drawing which shows an example of the reflection coefficient setting map of a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 configured as an internal combustion engine capable of outputting power from a hydrocarbon-based fuel such as gasoline and light oil, and an engine electronic control unit that drives and controls the engine 22. (Hereinafter referred to as the engine ECU) 24 and a carrier 34 for holding a plurality of pinion gears 33 so as to rotate and revolve freely are connected to a crankshaft 26 of the engine 22, and a differential gear 62 and a gear mechanism 60 are connected to driving wheels 63a and 63b. A power distribution integration mechanism 30 configured as a planetary gear mechanism in which the ring gear 32 is connected to a ring gear shaft 32a serving as a drive shaft connected via a sun gear, and a sun gear of the power distribution integration mechanism 30 configured as, for example, a synchronous generator motor. Motor MG1 connected to 31 and, for example, synchronous generator motor Motor MG2 having a rotor connected to ring gear shaft 32a via reduction gear 35, inverters 41 and 42 for driving motors MG1 and MG2, and by controlling switching of inverters 41 and 42, the motor As a nickel-metal hydride secondary battery that exchanges electric power with the motors MG1 and MG2 via the motor electronic control unit (hereinafter referred to as motor ECU) 40 that controls the driving of the MG1 and MG2 and the inverters 41 and 42 that share the power line 54. The battery 50 is configured, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the battery 50, and a hybrid electronic control unit 70 that controls the entire vehicle.

  The engine ECU 24 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. The engine ECU 24 inputs signals from various sensors (not shown) that detect the state of the engine 22, such as the rotational position of the crankshaft 26, the cooling water temperature of the engine 22, the throttle opening, the intake air amount, the intake air temperature, etc. Various control signals for driving the engine 22, for example, a drive signal to a fuel injection valve (not shown), a drive signal to a throttle valve (not shown), to an ignition coil (not shown) integrated with an igniter The control signal is output via the output port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  The motor ECU 40 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, for example, the rotational positions of the rotors of the motors MG1 and MG2 from the rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2. The rotational position, the phase current applied to the motors MG1 and MG2 detected by a current sensor (not shown), the inverter temperature from a temperature sensor (not shown) attached to the inverters 41 and 42, and the like are input. A switching control signal is output to a switching element (not shown) of the inverters 41 and 42. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44.

  The battery ECU 52 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. The battery ECU 52 is a signal necessary for managing the battery 50, for example, the battery voltage Vb from the voltage sensor 51a installed between the terminals of the battery 50, and the current sensor 51b attached to the positive output terminal of the battery 50. The charging / discharging current Ib from the battery 50, the battery temperature Tb from the temperature sensor 51c attached to the battery 50, and the like are input, and data relating to the state of the battery 50 is output to the hybrid electronic control unit 70 by communication as necessary. . Further, the battery ECU 52 determines the total capacity (storage capacity) stored in the battery 50 based on the integrated value of the charge / discharge current Ib detected by the current sensor 51b and the battery voltage Vb detected by the voltage sensor 51b. ) Is set as the estimated value of the storage ratio SOC, which is a ratio to the control power storage ratio SOC), or the battery 50 is charged based on the set control storage ratio SOCc and the battery temperature Tb from the temperature sensor 51c. Input / output limits Win and Wout, which are the maximum allowable power that may be discharged, are calculated. The input / output limits Win and Wout of the battery 50 set basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limit based on the control power storage ratio SOCc of the battery 50. The correction coefficient is set and the basic value of the set input / output limits Win and Wout is multiplied by the correction coefficient. The setting of the control power storage ratio SOCc of the battery 50 will be described later. Hereinafter, the storage ratio SOC of the battery 50 means an actual value, and will be described separately from estimated values such as the control storage ratio SOCc.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on. Both the torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22 and the motors MG1, MG2 are controlled so that the required power is output to the drive shaft 32 with the operation of the engine 22. Can be considered as an engine operation mode.

  Next, the operation of the thus configured hybrid vehicle 20 of the embodiment will be described. FIG. 2 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1, of the motors MG1, MG2. Nm2, the input / output limits Win and Wout of the battery 50, the value 0 is set as an initial value, and the value 1 is set when the control power storage ratio SOCc of the battery 50 is lowered to the charging required threshold value Smin or less. Then, a process of inputting data required for control, such as charge / discharge required power Pb * required by the battery 50, is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb and the control power storage ratio SOCc of the battery 50 and are input from the battery ECU 52 by communication. Furthermore, the forced charge request flag Fb is set to be input by a forced charge related setting routine described later executed by the hybrid electronic control unit 70. Further, in the embodiment, the charge / discharge required power Pb * is stored in the ROM 74 as a charge / discharge required power setting map by predetermining the relationship between the control power storage ratio SOCc of the battery 50 and the charge / discharge required power Pb *. When the control power storage ratio SOCc input by communication from the battery ECU 52 is given, the corresponding charge / discharge required power Pb * is derived and set from the stored map. FIG. 3 shows an example of the charge / discharge required power setting map. As shown in the figure, the charge / discharge required power Pb * increases to a predetermined positive power as the control power storage ratio SOCc is larger than the management center SOC * (for example, 60%) which is the management target value of the power storage ratio SOC of the battery 50. The value on the discharge request side that increases is set, and the value on the charge request side that decreases to a predetermined negative power as the control power storage ratio SOCc is smaller than the management center SOC * is set. Here, the description of the drive control is temporarily interrupted, and the setting of the control power storage ratio SOCc of the battery 50 will be described.

  FIG. 4 is a flowchart showing an example of a power storage ratio setting routine executed by the battery ECU 52. This routine is repeatedly executed by the battery ECU 52 every predetermined time (for example, every several msec). When the storage ratio setting routine is executed, the CPU (not shown) of the battery ECU 52 first inputs data necessary for setting such as the battery voltage Vb detected by the voltage sensor 51a and the charge / discharge current Ib detected by the current sensor 51b. Then, based on the integrated value of the input charge / discharge current Ib, the integrated storage rate SOC1 is calculated as a first estimated value of the storage rate SOC of the battery 50 (step S310), and the input battery voltage Vb is calculated. Based on this, a process of setting voltage storage rate SOC2 as the second estimated value of storage rate SOC of battery 50 is executed (step S320).

  Here, in the embodiment, the integrated power storage rate SOC1 is calculated by integrating the charging / discharging current Ib from a predetermined initial value as a value that reflects the actual power storage rate SOC of the battery 50, for example, when the vehicle is shipped. The calculation is continued by reading out and using the data stored in the flash memory (not shown) when the ignition is turned off and when the ignition is turned on the next time. In the embodiment, the voltage storage rate SOC2 is stored in a ROM (not shown) as a voltage storage rate setting map by predetermining the relationship between the battery voltage Vb and the voltage storage rate SOC2 so that the characteristics of the battery 50 are reflected. When the battery voltage Vb is given, the corresponding voltage storage rate SOC2 is derived from the stored map and set. FIG. 5 shows an example of the characteristics of the battery 50 expressed as a relationship between the storage ratio SOC of the battery 50 and the battery voltage Vb. In the figure, the predetermined low power storage ratio SL is a value smaller than the management center SOC * (for example, 45%), and the predetermined high power storage ratio SH is larger than the management center SOC * (for example, 80%). In addition, the charge required threshold value Smin for setting the value 1 to the forced charge flag Fb is set as a value (for example, 40% etc.) smaller than a predetermined low power storage ratio SL. An example of the value is shown. The predetermined low voltage Vbl is a battery voltage Vb corresponding to a predetermined low storage ratio SL in the characteristics of the battery 50, and the predetermined high voltage Vbh corresponds to a predetermined high storage ratio SH in the characteristics of the battery 50. Battery voltage Vb (a value higher than a predetermined low voltage Vbl). The battery 50 of the embodiment is a nickel metal hydride secondary battery, and, as shown in the drawing, a range in which the storage ratio SOC is less than a predetermined low storage ratio SL (hereinafter referred to as a low storage ratio range) or a predetermined high storage ratio SH. When it is in a large range (hereinafter referred to as a high power storage ratio range), the unit change amount (for example, 1%) of the power storage ratio SOC is compared to when the power storage ratio SOC is neither the low power storage ratio range nor the high power storage ratio range. The battery voltage Vb has a large change amount. In other words, when the battery voltage Vb is in a range less than a predetermined low voltage Vbl (hereinafter referred to as a low voltage range) or a range greater than a predetermined high voltage Vbh (hereinafter referred to as a high voltage range), the battery 50 Compared to when Vb is neither in the low voltage range nor in the high voltage range, the battery voltage Vb has a large change amount with respect to the unit change amount (for example, 1%) of the storage rate SOC. Therefore, in the voltage storage ratio setting map of the embodiment reflecting the characteristics of the battery 50, that is, the voltage storage ratio setting map obtained by replacing the storage ratio SOC of FIG. 5 with the voltage storage ratio SOC2, the voltage sensor When voltage storage ratio SOC2 is set by applying battery voltage Vb from 51a, battery voltage Vb is set to the low voltage range when battery voltage Vb is in the low voltage range or the high voltage range. As a result, the estimated value reflects the actual storage rate SOC of the battery 50 more correctly than when it is not in the high voltage range, and the estimated value can be used to set the control storage rate SOCc more correctly.

  Thus, when integrated storage rate SOC1 is calculated as the first estimated value of storage rate SOC of battery 50 and voltage storage rate SOC2 is set as the second estimated value, input battery voltage Vb is compared with predetermined high voltage Vbh. In step S330, the battery voltage Vb is compared with a predetermined low voltage Vbl (step S340). When the battery voltage Vb is equal to or lower than the predetermined high voltage Vbh and equal to or higher than the predetermined low voltage Vbl (high voltage range). And when the calculated voltage is not in the low voltage range, the calculated integrated power storage ratio SOC1 is set as the control power storage ratio SOCc (step S350), and the power storage ratio setting routine is terminated. As illustrated in FIG. 5, according to the characteristics of the battery 50, the voltage storage ratio SOC <b> 2 based on the battery voltage Vb is the actual storage of the battery 50 when the battery voltage Vb is neither in the low voltage range nor in the high voltage range. It is difficult to correctly reflect the ratio SOC. For this reason, in the embodiment, when the battery voltage Vb is not in the high voltage range or the low voltage range, the integrated power storage rate SOC1 that more accurately reflects the actual power storage rate SOC of the battery 50 than the voltage power storage rate SOC2 is set. The estimated power storage ratio SOCc was set. However, there is a possibility that the accumulated power storage rate SOC1 has a large error with respect to the actual power storage rate SOC as time elapses.

  When the battery voltage Vb is in a high voltage range higher than the predetermined high voltage Vbh, or when the battery voltage Vb is in a low voltage range lower than the predetermined low voltage Vbl, the voltage storage rate SOC2 is actually higher than the integrated storage rate SOC1. Is determined to be accurately reflected, and a reflection coefficient kv is set to a value 0 or more and 1 or less that determines a ratio for reflecting the voltage storage ratio SOC2 in the control storage ratio SOCc based on the battery voltage Vb ( In step S360), the product of the set reflection coefficient kv and the voltage storage ratio SOC2 plus the product of the value 1 minus the reflection coefficient kv (1-kv) and the integrated storage ratio SOC1 is added to the following formula (1 ) Is calculated as the integrated power storage ratio SOC (step S370), and the power storage ratio setting routine is terminated. Here, in the embodiment, the reflection coefficient kv is stored in a ROM (not shown) as a reflection coefficient setting map by predetermining the relationship between the battery voltage Vb and the reflection coefficient kv, and stored when the battery voltage Vb is given. The corresponding reflection coefficient kv is derived from the map and set. FIG. 6 shows an example of the reflection coefficient setting map. As shown in the figure, the reflection coefficient kv is set to a value of 0 when the battery voltage Vb is equal to or higher than a predetermined low voltage Vbl and equal to or lower than a predetermined high voltage Vbh, and decreases to a value of 1 as the battery voltage Vb is smaller than the predetermined low voltage Vbl. A value that increases is set, and a value that increases to a value of 1 as the battery voltage Vb is greater than the predetermined high voltage Vbh is set. Setting the reflection coefficient kv to a value that increases as the battery voltage Vb moves away from the range of the predetermined low voltage Vbl or higher and the predetermined high voltage Vbh or lower suppresses the control power storage ratio SOCc from being discontinuously changed. Because. In this way, when the battery voltage Vb becomes a low voltage range or a high voltage range, the control power storage ratio SOCc is calculated from the integrated power storage ratio SOC1 so that the voltage power storage ratio SOC2 is reflected (so that the voltage power storage ratio SOC2 is reflected). From the correction of the control power storage rate SOCc), the control power storage rate SOCc can be set to a value that more accurately reflects the actual power storage rate SOC when the actual power storage rate SOC of the battery 50 decreases. The setting of the control power storage ratio SOCc of the battery 50 has been described above. Returning to the description of drive control.

  SOCc = kv ・ SOC2 + (1-kv) ・ SOC1 (1)

  When the data is thus input, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V. And the required power Pe * required for the engine 22 is set (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 7 shows an example of the required torque setting map. The required power Pe * can be calculated by subtracting the charge / discharge required power Pb * required by the battery 50 from the product of the set required torque Tr * and the rotation speed Nr of the ring gear shaft 32a and adding a loss Loss. . The rotational speed Nr of the ring gear shaft 32a is obtained by multiplying the vehicle speed V by a conversion factor k (Nr = k · V), or the rotational speed Nm2 of the motor MG2 is divided by the gear ratio Gr of the reduction gear 35 (Nr = Nm2 / Gr).

  Subsequently, it is determined whether the engine 22 is operating or stopped (step S120). When the engine 22 is stopped, the required power Pe * is used to efficiently operate the engine 22. The engine 22 is compared with a threshold value Pstart determined as the lower limit of the range of the required power Pe * that should be started (step S130), the forced charge request flag Fb is checked (step S140), and the required power Pe * is equal to the threshold value Pstart. If the forced charge request flag Fb is less than 0 and it is determined that the engine 22 will continue to be stopped, the torque command Tm1 * of the motor MG1 is set to 0 (step S150).

  Subsequently, a value obtained by dividing the required torque Tr * by the gear ratio Gr of the reduction gear 35 is set as a temporary torque Tm2tmp which is a temporary value of torque to be output from the motor MG2 (step S160), and input / output of the battery 50 Torque limits Tm2min and Tm2max as upper and lower limits of torque that may be output from the motor MG2 are calculated by dividing the limits Win and Wout by the current rotational speed Nm2 of the motor MG2 (step S170), and the calculated temporary torque Tm2tmp is calculated. The torque command Tm2 * of the motor MG2 is set by limiting with the torque limits Tm2min and Tm2max according to the following equation (2) (step S180).

  Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (2)

  When the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are thus set, the set torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S190), and the drive control routine is terminated. The motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. By such control, it is possible to travel by outputting the required torque Tr * from the motor MG2 to the ring gear shaft 32a as the drive shaft. FIG. 8 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling in the motor operation mode. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown.

  When the required power Pe * is greater than or equal to the threshold value Pstart in step S130, it is determined that it is better to start the engine 22 in order to efficiently operate the engine 22, and the required power Pe * is less than the threshold value Pstart in steps S130 and S140. However, when the forced charge request flag Fb is a value 1, it is determined that it is better to start the engine 22 in order to increase the storage ratio SOC of the battery 50, and the engine 22 is started (step S200). Here, the engine 22 is started by outputting torque from the motor MG1 and outputting torque from the motor MG2 for canceling torque output to the ring gear shaft 32a as a drive shaft in accordance with the output of this torque. This is performed by cranking the engine 22 and starting fuel injection control, ignition control, etc. when the rotational speed Ne of the engine 22 reaches a predetermined rotational speed (for example, 1000 rpm). During the start of the engine 22, the drive control of the motor MG2 is performed so that the required torque Tr * is output to the ring gear shaft 32a. That is, the torque to be output from the motor MG2 is to cancel the torque for outputting the required torque Tr * to the ring gear shaft 32a and the torque acting on the ring gear shaft 32a when the engine 22 is cranked by the motor MG1. This is the sum of the torque and the torque.

  When the engine 22 is started, a target rotational speed Ne * and a target torque Te * are set as operating points at which the engine 22 should be operated based on the required power Pe * and an operation line for operating the engine 22 efficiently (step S210), using the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, the gear ratio ρ of the power distribution and integration mechanism 30, and the gear ratio Gr of the reduction gear 35, the target of the motor MG1 by the following equation (3): Formula (4) is calculated based on the calculated target rotational speed Nm1 *, the input rotational speed Nm1 of the motor MG1, the target torque Te * of the engine 22, and the gear ratio ρ of the power distribution and integration mechanism 30. To calculate the torque command Tm1 * to be output from the motor MG1 (step S220). FIG. 9 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *). Expression (3) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 10 shows an example of a collinear diagram showing the dynamic relationship between the rotation speed and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling in the engine operation mode. In the figure, two thick arrows on the R axis indicate that torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and torque Tm2 output from the motor MG2 is applied to the ring gear shaft 32a via the reduction gear 35. And acting torque. Expression (3) can be easily derived by using this alignment chart. Expression (4) is a relational expression in feedback control for rotating the motor MG1 at the target rotation speed Nm1 *. In Expression (4), “k1” in the second term on the right side is a gain of the proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / (Gr ・ ρ) (3)
Tm1 * =-ρ ・ Te * / (1 + ρ) + k1 ・ (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (4)

  Then, the torque command Tm1 * set to the required torque Tr * is added by dividing the torque command Tm1 * by the gear ratio ρ of the power distribution and integration mechanism 30 and further divided by the gear ratio Gr of the reduction gear 35 to obtain the temporary torque Tm2tmp of the motor MG2. The power consumption (power generation) of the motor MG1 obtained by multiplying the input / output limits Win and Wout of the battery 50 and the set torque command Tm1 * by the current rotational speed Nm1 of the battery 50 (step S230). The torque limit Tm2min, Tm2max of the motor MG2 is calculated by the following equations (6) and (7) (step S240) by dividing the deviation from the electric power) by the rotational speed Nm2 of the motor MG2, and the calculated temporary torque Tm2tmp is calculated by the equation The torque command Tm2 * of the motor MG2 is limited by the torque limits Tm2min and Tm2max according to (8). A constant (step S250). Here, Expression (5) can be easily derived from the alignment chart of FIG.

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (5)
Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (6)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (7)
Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (8)

  When the target rotational speed Ne * and target torque Te * of the engine 22 and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are thus set, the target rotational speed Ne * and the target torque Te * of the engine 22 are sent to the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S260), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * controls the intake air amount in the engine 22 so that the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as fuel injection control and ignition control. By such control, the required power Pe * can be efficiently output from the engine 22, and the required torque Tr * can be output to the ring gear shaft 32a as the drive shaft for traveling.

  When traveling using the power from the engine 22 is started, the next time this routine is executed, it is determined in step S120 that the engine 22 is in operation, and the required power Pe * is used to efficiently operate the engine 22. It is compared with a threshold value Pstop (a value slightly smaller than the threshold value Pstart) determined as the upper limit of the required power Pe * that should be stopped at the same time (step S270), and the forced charge request flag Fb is checked (step S280). . When the required power Pe * is larger than the threshold value Pstop, it is determined that it is better to continue the operation of the engine 22 in order to efficiently operate the engine 22, and the forced charge request is made even when the required power Pe * is equal to or lower than the threshold value Pstop. When the flag Fb is 1, it is determined that it is better to continue the operation of the engine 22 in order to increase the storage ratio SOC of the battery 50, and the target rotational speed Ne of the engine 22 is determined by the processing of steps S210 to S260 described above. *, Target torque Te *, torque commands Tm1 * and Tm2 * for the motors MG1 and MG2, are set and transmitted to the engine ECU 24 and the motor ECU 40, and the drive control routine is terminated.

  When the required power Pe * is equal to or less than the threshold value Pstop in steps S270 and S280 and the forced charge request flag Fb is 0, it is determined that the engine 22 is to be stopped, and the engine 22 is stopped (step S290). Through the processes of S150 to S190, torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are set and transmitted to the motor ECU 40, and the drive control routine is terminated.

  With this control, when the forced charge request flag Fb is 0, the required torque Tr * is output to the ring gear shaft 32a as the drive shaft with intermittent operation of the engine 22 based on the magnitude of the required power Pe * of the engine 22. You can travel. When the engine 22 is operated when the forced charge request flag Fb is 0, charging / discharging of the battery 50 is performed by the charge / discharge request power Pe * set such that the charging power increases as the control power storage ratio SOCc of the battery 50 decreases. Control is performed so that discharge is performed. When the forced charge request flag Fb is 1, the engine 22 can be continuously operated regardless of the required power Pe * of the engine 22 to output the required torque Tr * to the ring gear shaft 32a. it can. When the forced charge request flag Fb is a value 1, as will be described in detail later, this is a case where the storage ratio SOC of the battery 50 is equal to or less than the required charge threshold Smin, which is smaller than the control center SOC *, and thus is set as the charge power. Control is performed so that the battery 50 is charged by the generated power from the motor MG1 by the operation of the engine 22 by the charge / discharge required power Pb *. When the value of 1 is set in the forced charge request flag Fb during traveling while the engine 22 is stopped, the engine 22 is started. When the value of 0 is set in the forced charge request flag Fb after that, When the required power Pe * is less than or equal to the stop threshold value Pstop, the engine 22 is stopped. The drive control has been described above.

  Next, processing related to the setting of the forced charge request flag Fb of the battery 50 used in such drive control will be described. FIG. 11 is a flowchart showing an example of a forced charging related setting routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the forced charge-related setting routine is executed, the CPU 72 of the hybrid electronic control unit 70 first inputs data necessary for setting the forced charge request flag Fb such as the integrated power storage ratio SOC1 and the control power storage ratio SOCc of the battery 50. The process which performs is performed (step S400). The accumulated power storage rate SOC1 calculated based on the integrated value of the charge / discharge current Ib from the current sensor 51b by the power storage rate setting routine of FIG. 4 is input from the battery ECU 52 by communication. Further, the control power storage rate SOCc is communicated from the battery ECU 52 by the power storage rate setting routine shown in FIG. 4, which is set as the integrated power storage rate SOC1 or calculated based on the integrated power storage rate SOC1 and the voltage power storage rate SOC2. It was supposed to be entered by

  When the data is input in this way, a value 0 is set as an initial value, and a forced charge request flag Fb in which a value 1 or a value 0 is set according to the control power storage ratio SOCc in this routine is checked (step S410). When Fb is 0, the control power storage ratio SOCc is compared with the charge required threshold value Smin (step S420). The required charging threshold Smin is predetermined based on the storage capacity of the battery 50 as the upper limit of the range in which the storage ratio SOC of the battery 50 needs to be increased. In the embodiment, as illustrated in FIG. The value is set to a value (for example, 40%) smaller than a predetermined low power storage ratio SL.

  When the control power storage ratio SOCc of the battery 50 is larger than the charge required threshold Smin, it is determined that it is not necessary to increase the power storage ratio SOC of the battery 50, and the forced charge related setting routine is executed while the value 0 is held in the forced charge request flag Fb. finish. Further, when the control power storage ratio SOCc of the battery 50 is equal to or less than the charge necessary threshold value Smin, it is determined that the power storage ratio SOC of the battery 50 needs to be increased, and the value 1 is set to the forced charge request flag Fb (step S430). A value obtained by subtracting the control power storage ratio SOCc from the integrated power storage ratio SOC1 is calculated as a deviation ΔSOC (step S440), and it is determined whether or not the calculated deviation ΔSOC is equal to or greater than a predetermined ratio Sref (step S450). When the value 1 is set in the forced charge request flag Fb, the operation stop of the engine 22 is prohibited by the drive control illustrated in FIG. 2 and the operation of the engine 22 is continued. That is, control of the engine 22 and the motors MG1 and MG2 for running with the required torque Tr * while charging the battery 50 with the power generated by the motor MG1 while continuing the operation of the engine 22 (hereinafter referred to as forced charge running control). Will be started. Here, when starting the forced charging travel control, the predetermined ratio Sref decreases from a state where the control power storage ratio SOCc is estimated to be larger than the actual power storage ratio SOC and exceeds a permissible range, and the required charging threshold Smin It is for determining whether or not the following has occurred (hereinafter referred to as over-estimated decline), and a predetermined value such as 2% or 3% based on the storage capacity of the battery 50 is used. Can be used.

  When the calculated deviation ΔSOC is less than the predetermined ratio Sref, it is determined that it is not an excessive estimation decrease, and the charge end threshold Sfin, which is the control power storage ratio SOCc of the battery 50 when the forced charge travel control is ended, is greater than the charge required threshold Smin. A large first threshold value S1 (for example, 50%) is set (step S470), and when the calculated deviation ΔSOC is equal to or greater than the predetermined ratio Sref, it is determined that the overestimation has been reduced, and the charge required threshold value is set as the charge end threshold value Sfin. A second threshold value S2 (for example, 43%, 45%, etc.) larger than Smin but smaller than the first threshold value S1 is set (step S480). Then, the battery ECU 52 is instructed to replace the integrated power storage rate SOC1 of the battery 50 with the same value as the current control power storage rate SOCc (step S480), and the forced charge related control routine is terminated. The commanded battery ECU 52 replaces the value of the integrated storage ratio SOC1 and continues the calculation of the integrated storage ratio SOC1 by the storage ratio setting routine illustrated in FIG. As shown in FIG. 5 and FIG. 6, when the forced charging running control is started, the control power storage ratio SOCc of the battery 50 is equal to or less than the charge required threshold Smin, and the control power storage ratio SOCc is a voltage storage based on the battery voltage Vb. The ratio SOC2 is largely reflected and is a value that more accurately reflects the actual storage ratio SOC. Therefore, in the embodiment, when the forced charging traveling control is started, the accumulated power storage ratio SOC1 that may contain an error with respect to the actual power storage ratio SOC is replaced with the same value as the control power storage ratio SOCc. Thus, the subsequent integrated power storage ratio SOC1 can be calculated as a more correct value. The reason for changing the charging end threshold value Sfin in accordance with the magnitude relationship between the deviation ΔSOC and the predetermined ratio Sref will be described later.

  When the forced charge running control is started in this way, the next time this routine is executed, it is determined in step S410 that the forced charge request flag Fb is a value 1, and the input control power storage ratio SOCc is compared with the set charge end threshold value Sfin. (Step S490), when the control power storage ratio SOCc is less than the charging end threshold Sfin, it is determined that the forced charging traveling control is continued, and the forced charging request flag Fb is maintained with the value 1 and the forced charging related setting routine is ended. To do. On the other hand, when the input control power storage ratio SOCc is equal to or greater than the set charge end threshold value Sfin, it is determined that the forced charge travel control is to be ended, the value 0 is set in the forced charge request flag Fb (step S500), and forced charge related settings are set. End the routine. When the value 0 is set in the forced charge request flag Fb in this manner, the engine 22 is permitted to be stopped by the drive control illustrated in FIG. 2, and the engine 22 is intermittently operated based on the required power Pe * of the engine 22. . That is, the forced charging travel control ends.

  Here, when the forced charging traveling control is started, the charging end threshold value Sfin is changed according to the magnitude relationship between the deviation ΔSOC obtained by subtracting the control power storage ratio SOCc from the integrated power storage ratio SOC1 of the battery 50 and the predetermined ratio Sref. The reason will be explained. FIG. 12 is an explanatory diagram showing an example of a time change state of the control power storage ratio SOCc and the deviation ΔSOC of the battery 50 and its magnitude and the forced charge request flag Fb. In the figure, in order to compare with the control power storage ratio SOCc indicated by the solid line, the cumulative power storage ratio SOC1 is indicated by a one-dot chain line, and the first threshold value S1 is set as the charge end threshold value Sfin regardless of the magnitude of the deviation ΔSOC. The control power storage ratio SOCc at is indicated by a broken line. The deviation ΔSOC is shown as having a large deviation when the deviation ΔSOC is equal to or greater than the predetermined ratio Sref, and as having a small deviation when the deviation ΔSOC is less than the predetermined ratio Sref. When the control power storage rate SOCc decreases due to the discharge from the battery 50 and the battery voltage Vb becomes less than the predetermined low voltage Vbl and the voltage power storage rate SOC2 is reflected, the correction of the control power storage rate SOCc starts (time t1). Since the actual power storage rate SOC is smaller than the cumulative power storage rate SOC1, a difference occurs between the cumulative power storage rate SOC1 and the control power storage rate SOCc, and the control power storage rate SOCc is increased in a state where the deviation ΔSOC is greater than or equal to the predetermined rate Sref. However, there is a case where the forced charging traveling control is started when the overestimated lowering becomes equal to or less than the charging required threshold value Smin (time t2). For example, when the state in which the battery 50 is at a high temperature and the amount of discharge due to self-discharge continues is large, it is likely to be an overestimated decline. In the case of such an excessive estimation decrease, if the forced charging travel control is continued until the control power storage ratio SOCc reaches a relatively large first threshold value S1 (time t4) as in the comparative example indicated by the broken line, the operation of the engine 22 is performed. The combustion consumption due to will continue in vain. The reason for wasting is that, when the overestimation is reduced, the control power storage ratio SOCc is larger than the actual power storage ratio SOC beyond the allowable range, so the charge / discharge required power Pe * is set to be small as the charge power. If the control power storage rate SOCc can be made closer to the actual power storage rate SOC, there is room for recovery of the battery 50 power storage rate SOC by running of the vehicle. It is because it can be said that it was in the state. Therefore, when it is determined that the overestimation is reduced when the forced charging traveling control is started, the forced charging traveling control is performed only until the control power storage ratio SOCc becomes a relatively small second threshold value S2. By not continuing (time t3), the combustion consumption of the engine 22 can be suppressed. On the other hand, if it is determined that the overestimation is not reduced when the forced charging traveling control is started, it is determined that there is little room for recovering the storage rate SOC depending on the traveling of the vehicle such as during a traffic jam, for example, and the forced charging traveling control is performed. Is continued until the control power storage ratio SOCc reaches a relatively large first threshold value S1, so that the actual power storage ratio SOC can be recovered.

  According to the hybrid vehicle 20 of the embodiment described above, the operation of the engine 22 is continued and the battery 50 is charged by the electric power from the motor MG1 when the control power storage ratio SOCc of the battery 50 is equal to or less than the charging required threshold Smin. However, when starting the forced charging traveling control for controlling the engine 22 and the motors MG1, MG2 to travel with the required torque Tr *, the control power storage ratio SOCc of the battery 50 is larger than the actual power storage ratio SOC beyond the allowable range. When it is not an overestimated decline when the control power storage ratio SOCc is less than or equal to the required charging threshold Smin due to a drop from the state, forced charging is performed until the control power storage ratio SOCc reaches a first threshold value S1 determined as a value greater than the required charging threshold Smin. On the other hand, overestimate when starting forced charge travel control while continuing travel control When the time is lower, the forced charge traveling control is continued until the control power storage ratio SOCc becomes larger than the charge required threshold value Smin and the second threshold value S2 smaller than the first threshold value S1. The forced charging travel control can be terminated at the timing when the ratio SOCc is reached, and fuel consumption due to operation of the engine 22 can be more appropriately suppressed.

  In the hybrid vehicle 20 of the embodiment, the integrated power storage rate SOC1 is replaced with the same value as the control power storage rate SOCc when the forced charge travel control is started. However, even after the forced charge travel control is started, for example, the battery voltage Such replacement may be performed before Vb reaches a predetermined low voltage threshold value Vbl. Further, when the forced charging traveling control is started, a setting may be made to replace the integrated power storage rate SOC1 with the same value as the voltage power storage rate SOC2.

  In the hybrid vehicle 20 of the embodiment, the reflection coefficient kv for reflecting the voltage storage ratio SOC2 in the control storage ratio SOCc is 0 when the battery voltage Vb is equal to or higher than the predetermined low voltage Vbl and lower than the predetermined high voltage Vbh. It is assumed that a value that increases to value 1 is set as the battery voltage Vb is smaller than the predetermined low voltage Vbl, and a value that increases to value 1 is set as the battery voltage Vb is higher than the predetermined high voltage Vbh. However, as illustrated in the reflection coefficient setting map of the modification of FIG. 13, when the battery voltage Vb is equal to or higher than the predetermined low voltage Vbl and equal to or lower than the predetermined high voltage Vbh, a positive value smaller than 0.5 is set. As the battery voltage Vb is smaller than the predetermined low voltage Vbl, a value that increases to a certain value less than 1 and greater than 0.5 is set. Or as Li voltage Vb becomes large value to a value with a higher value less than 0.5 greater than 1 greater than the predetermined high voltage Vbh is set. In this case, the processing of steps S360 and S370 may be executed following the processing of step S320 without executing the processing of steps S330 to S350 of the power storage ratio setting routine of FIG.

  In the hybrid vehicle 20 of the embodiment, the control power storage ratio SOCc is set by comparing the battery voltage Vb with the predetermined high voltage Vbh or the predetermined low voltage Vbl by the power storage ratio setting routine illustrated in FIG. As shown in the power storage ratio setting routine of the modification of FIG. 14, the control power storage ratio SOCc may be set by comparing the integrated power storage ratio SOC1 with a predetermined high power storage ratio SH or a predetermined low power storage ratio SL. In the routine of FIG. 14, the same processing as that of the routine of FIG. 4 is denoted by the same step number, and detailed description thereof is omitted. In the routine of FIG. 14, when the integrated storage ratio SOC1 of the battery 50 is calculated and the battery storage ratio SOC2 is set, the integrated storage ratio SOC1 is compared with a predetermined high storage ratio SH (step S600), and the integrated storage ratio SOC1 is set. When compared with the predetermined low power storage ratio SL (step S610), when the integrated power storage ratio SOC1 is not in the high power storage ratio range larger than the predetermined high power storage ratio SH and not in the low power storage ratio range smaller than the predetermined low power storage ratio SL. Then, the integrated power storage rate SOC1 is set as the control power storage rate SOCc (step S350). On the other hand, when the integrated power storage ratio SOC1 is in the high power storage ratio range or in the low power storage ratio range, the reflection coefficient kv is determined using a predetermined reflection coefficient setting map illustrated in FIG. 15 based on the integrated power storage ratio SOC1. Is set (step S620), the control power storage ratio SOCc is calculated using the above-described equation (1) so that the voltage storage ratio SOC2 is largely reflected by the control power storage ratio SOCc (step S370), and this routine is terminated. To do. In the reflection coefficient setting map of FIG. 15, the reflection coefficient kv is set to a value of 0 when the integrated storage ratio SOC1 is not less than a predetermined low storage ratio SL and not more than a predetermined high storage ratio SH, and the integrated storage ratio SOC1 is a predetermined value. A value that increases to a value 1 is set as it is smaller than the low power storage ratio SL, and a value that is increased to a value 1 as the integrated power storage ratio SOC1 is larger than a predetermined high power storage ratio SH. Even with this setting, the control power storage ratio SOCc can be set to a value that more accurately reflects the actual power storage ratio SOC when the actual power storage ratio SOC of the battery 50 is lowered.

  In the hybrid vehicle 20 of the embodiment, the battery 50 is a nickel hydride secondary battery. However, when the storage rate SOC is within the predetermined storage rate range including the low storage rate range, the storage rate SOC is out of the predetermined storage rate range. A characteristic that the amount of change of the battery voltage Vb with respect to the unit change amount of the storage rate SOC is larger than that of the case, in other words, when the battery voltage Vb is within a predetermined voltage range including a low voltage range, the battery voltage Vb is out of the predetermined voltage range. Any secondary battery may be used as long as it has a characteristic that the change amount of the battery voltage Vb with respect to the unit change amount of the storage rate SOC is larger than that of the case.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is changed by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modification of FIG. May be output to an axle (an axle connected to the wheels 64a and 64b in FIG. 14) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, and the power from the motor MG2 is reduced to the reduction gear. The power is generated by the motor MG1 using the power from the engine 22 as illustrated in the hybrid vehicle 220 of the modified example of FIG. At the same time, the electric power from the battery 50 may be used to output power to the drive shaft connected to the drive wheels 63a and 63b by the motor MG2. Further, as illustrated in the hybrid vehicle 320 of the modified example of FIG. 18, a motor MG is attached to a drive shaft connected to the drive wheels 63 a and 63 b via a transmission 330, and a rotation shaft of the motor MG is connected to a rotation shaft via a clutch 329. The engine 22 is connected, and the power from the engine 22 is output to the drive shaft via the rotating shaft of the motor MG and the transmission 330, and the power from the motor MG is output to the drive shaft via the transmission 330. It is good also as what to do. That is, a generator capable of generating electric power using the power from the internal combustion engine as long as it includes an internal combustion engine and a generator capable of generating electric power using the power from the internal combustion engine and an electric motor capable of inputting and outputting driving power. Any type of hybrid vehicle may be used, including a hybrid vehicle that includes a single generator motor that functions as a motor that can function as a motor that can input and output driving power.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to an “internal combustion engine”, the motor MG1 corresponds to a “generator”, the motor MG2 corresponds to a “motor”, the battery 50 corresponds to a “secondary battery”, and charging / discharging. The battery ECU 52 that executes the storage ratio setting routine of FIG. 4 for setting the control storage ratio SOCc, which is an estimated value of the storage ratio SOC of the battery 50 based on the current Ib and the battery voltage Vb, corresponds to the “estimated storage ratio calculation means”. When the forced charge request flag Fb is 0, the battery 50 is charged / discharged based on the charge / discharge required power Pb * when the engine 22 is operated, and the engine 22 is intermittently operated based on the required power Pe * of the engine 22. When the forcible charge request flag Fb is a value 1, the charge is released when the required torque Tr * is output to the ring gear shaft 32a as the drive shaft. Regardless of the required power Pe * of the engine 22 with the charging of the battery 50 based on the required power Pe *, the engine 22 is continuously operated to output the required torque Tr * to the ring gear shaft 32a. The drive control routine of FIG. 2 for setting the target rotational speed Ne * and target torque Te * of the engine 22 and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 is executed, or the control power storage ratio SOCc of the battery 50 is charged. When the forced charge running control is started when the required threshold value Smin or less is determined, it is determined whether or not it is an overestimated decrease, and the charge end threshold value Sfin is set to the first threshold value S1 or the second threshold value S2 depending on the determination result. 11 is set and the forced charging request flag Fb is kept at a value 1 until the control power storage ratio SOCc reaches the charging end threshold value Sfin. A hybrid electronic control unit 70 that executes a constant routine, an engine ECU 24 that controls the engine 22 based on a target rotational speed Ne * and a target torque Te *, and motors MG1 and MG2 based on torque commands Tm1 * and Tm2 *. The motor ECU 40 to be controlled corresponds to “control means”. The power distribution and integration mechanism 30 corresponds to a “planetary gear mechanism”.

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. . The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of generator as long as it can generate power using power from an internal combustion engine, such as an induction motor. It doesn't matter. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output driving power, such as an induction motor. . The “secondary battery” is not limited to the battery 50, which is a nickel metal hydride secondary battery, but any other type of secondary battery as long as it can exchange power with the generator and the motor. It doesn't matter. The “estimated power storage ratio calculation means” is not limited to the battery ECU 52 that executes the power storage ratio setting routine of FIG. 4, but the total power storage amount stored in the secondary battery based on the state of the secondary battery. As long as the estimated power storage ratio is calculated as an estimated value of the power storage ratio that is a ratio to the capacity, any value may be used. The “control means” is not limited to the combination of the hybrid electronic control unit 70, the engine ECU 24, and the motor ECU 40, and may be configured by a single electronic control unit. Further, the “control means” is not limited to the drive control illustrated in FIG. 2 or the forced charge-related setting illustrated in FIG. 11, but the set estimated power storage ratio needs to be charged in advance. Until the threshold value is reached, when the internal combustion engine is operated, the secondary battery is charged with charging power that tends to increase as the estimated power storage ratio decreases, and the required driving force required for traveling with intermittent operation of the internal combustion engine The internal combustion engine, the generator, and the motor are controlled so as to run, and when the set estimated power storage ratio falls below the threshold required for charging, the internal combustion engine is continuously operated and the secondary battery is charged with the electric power from the generator. In addition, the forced charging traveling control is performed to control the internal combustion engine, the generator, and the motor so as to travel with the requested driving force. If the estimated power storage ratio that is set to be lower than the actual power storage ratio exceeds the permissible range and is less than the required charging threshold is not an overestimated decrease, the set estimated power storage ratio is greater than the required charging threshold. The forced charge running control is continued until a predetermined first charge end threshold value is reached, and when the overestimation is reduced, the set estimated power storage ratio is greater than the charge required threshold value and the first charge end threshold value is reached. Any method may be used as long as the forced charging traveling control is continued until a smaller second charging end threshold value is reached. In addition, the “planetary gear mechanism” is not limited to the power distribution and integration mechanism 30 described above, and uses a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms to connect to four or more shafts. What is a four-shaft type, etc., in which three rotating elements are connected to the three axes of the output shaft of the internal combustion engine, the rotating shaft of the generator and the driving shaft connected to the motor shaft. Anything is acceptable.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20, 120, 220, 320 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 Carrier, 35 Reduction gear, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 Battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Battery electronics Control unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 electronic control unit for hybrid, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 329 clutch, 330 transmission, MG1 , MG2, MG motor.

Claims (6)

An internal combustion engine, a generator capable of generating electric power using power from the internal combustion engine, an electric motor capable of inputting and outputting power for traveling, a secondary battery capable of exchanging electric power with the generator and the electric motor, An estimated power storage ratio calculating means for calculating an estimated power storage ratio as an estimated value of a power storage ratio that is a ratio of the power storage amount stored in the secondary battery to the total capacity based on the state of the secondary battery; Until the estimated power storage ratio falls below a predetermined charging threshold, the secondary battery is charged with charging power that tends to increase as the estimated power storage ratio decreases when the internal combustion engine is operated. The internal combustion engine, the generator, and the electric motor are controlled to travel with a required driving force required for traveling with intermittent operation, and the calculated estimated power storage ratio is less than or equal to the required charging threshold. When the internal combustion engine continues to operate, the secondary battery is charged with the electric power from the generator, and the internal combustion engine, the generator, and the electric motor are controlled to run with the required driving force. A hybrid vehicle comprising control means for performing charge travel control,
When the control means starts the forced charging travel control, the estimated power storage ratio is decreased from a state where the estimated power storage ratio exceeds the allowable power storage ratio beyond the actual power storage ratio of the secondary battery, and the calculated estimated power storage ratio is When it is not at the time of an excessive estimation decrease that has become equal to or less than the required charging threshold, the forced charging traveling control is performed until the calculated estimated power storage ratio reaches a first charging end threshold that is predetermined as a value that is greater than the required charging threshold. If the overestimated reduction is continued, the forced charge running control is performed until the calculated estimated power storage ratio reaches a second charge end threshold value that is greater than the charge required threshold value and smaller than the first charge end threshold value. Is a means to continue
Hybrid car. The hybrid vehicle according to claim 1,
The secondary battery is configured such that when the voltage of the secondary battery is within a predetermined voltage range including at least a predetermined low voltage range, the secondary battery with respect to the unit change amount of the storage ratio is greater than when the voltage is outside the predetermined voltage range. Battery characteristics that increase the amount of voltage change
The estimated power storage ratio calculating means calculates an integrated power storage ratio that is a first estimated value of the power storage ratio based on an integrated value of a current that charges and discharges the secondary battery, and based on a voltage of the secondary battery. A voltage storage ratio, which is a second estimated value of the storage ratio, is set using a predetermined relationship between the voltage of the secondary battery and the storage ratio reflecting the battery characteristics, and the secondary battery When the voltage of the secondary battery is outside the predetermined voltage range, the estimated power storage ratio is calculated to be closer to the calculated cumulative power storage ratio than the set voltage storage ratio, and the voltage of the secondary battery is set to the predetermined voltage range. Is a means for calculating the estimated power storage ratio so that the voltage of the secondary battery is closer to the set voltage storage ratio as the voltage of the secondary battery goes away from outside the predetermined voltage range,
The control means controls when the overestimated lowering is the time when the calculated estimated power storage ratio is smaller than the calculated total power storage ratio by a predetermined percentage or more when starting the forced charging travel control. Is,
Hybrid car. The hybrid vehicle according to claim 1,
The secondary battery is configured such that when the power storage ratio is within a predetermined power storage ratio range including at least a predetermined low power storage ratio range, the secondary battery with respect to a unit change amount of the power storage ratio is greater than when the power storage ratio is outside the predetermined power storage ratio range. Battery characteristics that increase the amount of voltage change
The estimated power storage ratio calculating means calculates an integrated power storage ratio that is a first estimated value of the power storage ratio based on an integrated value of a current that charges and discharges the secondary battery, and based on a voltage of the secondary battery. A voltage storage ratio, which is a second estimated value of the storage ratio, using a predetermined relationship between the voltage of the secondary battery and the storage ratio reflecting the battery characteristics, and the calculated integration When the storage ratio is outside the predetermined storage ratio range, a value closer to the calculated integrated storage ratio than the set voltage storage ratio is calculated as the estimated storage ratio, and the calculated integrated storage ratio is within the predetermined storage ratio range. Is a means for calculating, as the estimated power storage ratio, a value that tends to be closer to the set voltage power storage ratio as the calculated cumulative power storage ratio moves away from outside the predetermined power storage ratio range,
The control means controls when the overestimated lowering is the time when the calculated estimated power storage ratio is smaller than the calculated total power storage ratio by a predetermined percentage or more when starting the forced charging travel control. Is,
Hybrid car. A hybrid vehicle according to claim 2 or 3,
The estimated power storage ratio calculating means is means for replacing the integrated power storage ratio with a value equal to the estimated power storage ratio when the forced charging travel control starts.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 4,
The control means starts the forced charging traveling control with the start of the internal combustion engine while traveling with the operation of the internal combustion engine stopped, and ends the forced charging traveling control. Means for controlling the internal combustion engine so that the operation of the internal combustion engine is stopped when the operation of the internal combustion engine is not required;
Hybrid car. A hybrid vehicle according to any one of claims 1 to 5,
A hybrid vehicle comprising a planetary gear mechanism in which three rotating elements are connected to three axes of an output shaft of the internal combustion engine, a rotating shaft of the generator, and an axle connected to a driving shaft to which the electric motor is connected.

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