JP4438815B2 - Vehicle and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform much proper control in starting an engine whose operation stops in a vehicle on which an engine and a motor are loaded, and to suppress the inter-terminal voltage of a battery for transferring power with the motor from becoming less than a lower limit voltage. <P>SOLUTION: During motor traveling, a threshold Vref for a voltage is set as a threshold for starting an engine based on a vehicle speed V and a residual capacity SOC (step S160), and when an inter-terminal voltage Vb of the battery is less than a set threshold Vref for a voltage (step S170), the engine is motored and started (steps S200 to S230, S280 to S300). Thus, it is possible to suppress the inter-terminal voltage Vb of the battery from becoming less than a lower limit voltage for discharging the battery. Thus, it is possible to start the engine in a much more proper timing. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a vehicle and a control method thereof.

Conventionally, as this type of vehicle, an engine that outputs driving power, a first motor that can motor the engine, a second motor that outputs driving power, a first motor and a second motor, A vehicle including a battery that exchanges electric power has been proposed (see, for example, Patent Document 1). In this vehicle, when traveling using the power from the second motor, the electric power necessary for engine motoring can be continuously output based on the current state of charge of the battery and a predetermined voltage model. The time is estimated, and the battery is used to the limit by starting the engine when the estimated duration reaches the time required to start the motor by motoring the first motor.
JP 2003-153402 A

  In the above-described vehicle, when the engine that has been stopped is motored by the first motor and started, the battery power is consumed by the motoring, so that the voltage between the terminals of the battery decreases. In order to prevent the battery terminal voltage from falling below a lower limit voltage at which power cannot be extracted from the battery due to such battery power consumption, the battery terminal voltage is generally set to the battery regardless of the current battery state or vehicle state. Control is performed to start the engine when it falls to a predetermined voltage threshold value that is higher than the lower limit voltage, but since such a voltage threshold value is set as a predetermined value, Depending on the state of the battery, etc., the engine may not be started at an appropriate timing.

  A vehicle and a control method thereof according to the present invention are provided in a vehicle equipped with an internal combustion engine and an electric motor, and including a starting device used for starting the internal combustion engine, and a power storage device capable of exchanging electric power with the electric motor and the starting device. An object of the present invention is to start the internal combustion engine at a more appropriate timing when starting the internal combustion engine stopped by the apparatus, and to suppress the voltage across the terminals of the power storage device from falling below the lower limit voltage.

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

The vehicle of the present invention
A vehicle equipped with an internal combustion engine and an electric motor and capable of traveling using at least power from the electric motor,
Engine starting means used for starting the internal combustion engine;
Power storage means capable of exchanging electric power with the electric motor and the engine starting means;
Voltage detecting means for detecting a voltage between terminals of the power storage means;
A voltage drop degree estimating means for estimating the drop degree of the voltage between the terminals of the power storage means;
Threshold setting means for setting a threshold for voltage for starting the internal combustion engine based on the estimated degree of decrease in the inter-terminal voltage;
The internal combustion engine and the engine so as to continue the shutdown of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold when the internal combustion engine is in a shutdown state. Engine starting control for controlling the internal combustion engine and the engine starting means so as to start the internal combustion engine when the detected inter-terminal voltage reaches less than the set voltage threshold value. Means,
It is a summary to provide.

  In the vehicle according to the present invention, the degree of decrease in the voltage between the terminals of the power storage means is estimated, and a voltage threshold value for starting the internal combustion engine is set based on the estimated degree of decrease in the voltage between terminals. Then, when the internal combustion engine is in a stopped state, the internal combustion engine and the engine starting means are arranged so as to continue the operation stop of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold. The internal combustion engine and the engine starting means are controlled so that the internal combustion engine is started when the detected inter-terminal voltage falls below a set voltage threshold. The voltage threshold for starting the internal combustion engine is set on the basis of the estimated decrease in the voltage between the terminals of the power storage means and based on the estimated decrease in the voltage between the terminals. The internal combustion engine can be started at a more appropriate timing as compared with the voltage value used as the voltage threshold value, and the terminal voltage of the power storage means can be prevented from falling below the lower limit voltage of the power storage means.

  In such a vehicle of the present invention, the voltage drop estimation means is a means for estimating the degree of reduction in the voltage between the terminals based on at least one of a vehicle speed, a state of the power storage means, and an accelerator opening. You can also In this case, the voltage drop estimation means may determine the voltage between the terminals based on at least one of the remaining capacity of the power storage means, the temperature of the power storage means, and the open voltage of the power storage means as the state of the power storage means. It can also be a means for estimating the degree of decrease of In the case of estimating the degree of decrease in the voltage between the terminals based on at least one of the remaining capacity of the power storage means, the temperature of the power storage means, and the open voltage of the power storage means as the state of the power storage means, the voltage drop estimation means is The degree of decrease in the inter-terminal voltage tends to decrease as the remaining capacity of the power storage means increases, and the threshold setting means tends to decrease as the estimated decrease in inter-terminal voltage decreases. It may be a means for setting a threshold value. Further, the voltage drop estimation means estimates the degree of decrease in the voltage between the terminals so that the voltage decreases as the temperature of the power storage means increases, or the voltage between the terminals tends to decrease as the open circuit voltage of the power storage means increases. It is also possible to estimate the degree of decrease. It is considered that as the remaining capacity of the power storage means increases and the temperature and open circuit voltage of the power storage means increase, the degree of voltage drop of the power storage means associated with power consumption when starting the internal combustion engine is reduced. Therefore, by setting the voltage threshold value smaller as the remaining capacity of the power storage means becomes larger, or by setting the voltage threshold value smaller as the temperature of the power storage means and the open circuit voltage become higher, the internal combustion engine has a timing according to the state of the power storage means. Can be started.

  In the vehicle of the present invention, the voltage drop estimating means is a means for estimating the degree of decrease in the voltage between the terminals in a tendency to increase as the accelerator opening decreases, and the threshold setting means is the estimated value. It may be a means for setting the voltage threshold in such a manner that the degree of decrease in the inter-terminal voltage decreases. Since the required driving force required by the driver is smaller as the accelerator opening becomes smaller, it is considered that the degree of decrease in the voltage between the terminals of the power storage means is small when starting the internal combustion engine. Therefore, the internal combustion engine can be started at a timing corresponding to the accelerator opening by setting the voltage threshold so that the accelerator opening decreases as the accelerator opening decreases.

  Further, in the vehicle of the present invention, the engine start control means is detected when the vehicle is traveling in a motor travel mode in which the internal combustion engine is stopped using the power from the electric motor. Until the voltage between the terminals reaches less than the set voltage threshold, the internal combustion engine, the engine starting means, and the electric motor are controlled so as to continue running in the motor running mode, and the detected terminals It may be a means for controlling the internal combustion engine, the engine starting means, and the electric motor so that the internal combustion engine is started and travels when the voltage falls below the set voltage threshold value. If it carries out like this, even when it drive | works in motor drive mode, it can transfer to the state which starts an internal combustion engine more appropriately from motor drive mode and drive | works.

  In the vehicle of the present invention, the vehicle further includes learning means for learning a voltage drop amount of the inter-terminal voltage when the internal combustion engine is started, and the voltage drop estimation means is connected to the terminal based on the learned voltage drop amount. It may be a means for estimating the degree of decrease in the inter-voltage. In this way, the voltage threshold can be set more appropriately.

  In the vehicle of the present invention, the engine starting means is means capable of motoring the output shaft of the internal combustion engine, and the engine start control means is configured such that when the internal combustion engine is started, the output shaft of the internal combustion engine is It can also be a means for controlling the engine starting means to be motored. In this way, when the internal combustion engine is started, more appropriate control can be performed even when the electric power of the power storage means is consumed along with motoring of the output shaft of the internal combustion engine. In this case, the engine starting means is connected to a drive shaft connected to an axle and an output shaft of the internal combustion engine, and is connected to the drive shaft by input and output of power and power, and the internal combustion engine The electric motor may be an electric motor that inputs / outputs power to / from the drive shaft. In the case of including such power power input / output means, the power power input / output means is connected to the output shaft, the drive shaft, and the third shaft of the internal combustion engine and enters any two of the three shafts. It may be a means provided with a three-shaft power input / output means for inputting / outputting power to the remaining one shaft based on the output power and a generator for inputting / outputting power to / from the third shaft. it can. When such electric power output means includes a three-axis power input / output means and a generator, the electric power output means includes required drive force setting means for setting required drive force required for the drive shaft, and the voltage drop estimation means includes It is means for estimating the degree of decrease in the terminal voltage so as to decrease as the vehicle speed increases, and the threshold setting means sets the voltage threshold in a tendency to decrease as the estimated degree of decrease in terminal voltage decreases. The engine start control means continues to stop the operation of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold, and the set required driving force. The internal combustion engine, the generator, and the electric motor are controlled so that a driving force based on the output is output to the drive shaft, and the detected inter-terminal voltage is less than the set voltage threshold. When the output shaft of the internal combustion engine is motored, the driving force output to the drive shaft based on the change in the rotational speed of the generator and the drive output from the generator to the drive shaft are started. The internal combustion engine, the generator, and the generator so that a driving force based on the set required driving force is output to the driving shaft by a driving force that is a sum of a force and a driving force output from the electric motor to the driving shaft. It may be a means for controlling the electric motor. When the detected inter-terminal voltage falls below a set voltage threshold, the output shaft of the internal combustion engine is motored and started, and the driving force output to the drive shaft based on the change in the rotational speed of the generator The driving force based on the required driving force set by the sum of the driving force output from the motoring means to the driving shaft and the driving force output from the electric motor to the driving shaft is output to the driving shaft. The engine, generator and motor are controlled. At this time, depending on the driving force output to the drive shaft based on the change in the rotational speed of the generator, the regenerative braking force may be output from the electric motor. However, the higher the vehicle speed, the higher the rotational speed of the electric motor. Since the generated power increases, it is considered that the degree of decrease in the voltage between the terminals of the power storage means is reduced. Therefore, by setting the voltage threshold value so that it decreases as the vehicle speed increases, the voltage threshold value can be set to a more appropriate value, and can be started at a more appropriate timing when starting the internal combustion engine. .

The vehicle control method of the present invention includes:
An internal combustion engine and an electric motor are mounted, and an engine starting means used for starting the internal combustion engine, an electric storage means capable of exchanging electric power with the electric motor and the engine starting means, and a voltage between terminals of the electric storage means are detected. A method for controlling a vehicle including a voltage detection means and capable of traveling using at least power from the electric motor,
Estimating the degree of voltage drop between the terminals of the power storage means,
Setting a threshold for voltage for starting the internal combustion engine based on the estimated decrease in the voltage between the terminals,
The internal combustion engine and the engine so as to continue the shutdown of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold when the internal combustion engine is in a shutdown state. And controlling the internal combustion engine and the engine starting means so that the internal combustion engine is started when the detected inter-terminal voltage reaches a value less than the set voltage threshold. And

  In this vehicle control method of the present invention, the degree of decrease in the voltage between the terminals of the power storage means is estimated, and a voltage threshold value for starting the internal combustion engine is set based on the estimated degree of decrease in the voltage between terminals. Then, when the internal combustion engine is in a stopped state, the internal combustion engine and the engine starting means are arranged so as to continue the operation stop of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold. The internal combustion engine and the engine starting means are controlled so that the internal combustion engine is started when the detected inter-terminal voltage falls below a set voltage threshold. Since the voltage threshold for starting the internal combustion engine is set based on the estimated decrease in the voltage between the terminals of the power storage means and the estimated decrease in the voltage between the terminals, the voltage threshold is set to a predetermined value. The internal combustion engine can be started at a more appropriate timing as compared to the one used as a power source, and when the internal combustion engine is started, the voltage across the terminals of the power storage means is prevented from falling below the lower limit voltage of the power storage means due to power consumption. can do.

  Next, the best mode for carrying out the present invention will be described using examples.

  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, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, And a hybrid electronic control unit 70 for controlling the entire power output apparatus.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. 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 power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. 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 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, an inter-terminal voltage Vb from a voltage sensor 50 a installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. Further, the battery ECU 52 calculates the remaining capacity (SOC) based on the integrated value of the charging / discharging current detected by the current sensor in order to manage the battery 50, and calculates the remaining capacity (SOC) and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the above. The input / output limits Win and Wout of the battery 50 are set to the 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 are set based on the remaining capacity (SOC) of the battery 50. It can be set by setting a correction coefficient for restriction and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient. FIG. 3 shows an example of the relationship between the battery temperature Tb and the input / output limits Win, Wout, and FIG. 4 shows an example of the relationship between the remaining capacity (SOC) of the battery 50 and the correction coefficients of the input / output limits Win, Wout.

  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.

  Next, the operation of the thus configured hybrid vehicle 20 of the embodiment will be described. FIG. 5 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 Ne of the engine 22, the motor MG1. , MG2 rotation speeds Nm1 and Nm2, input / output limits Win and Wout of battery 50, terminal voltage Vb, and other data necessary for control are executed (step S100). Here, the rotational speed Ne of the engine 22 is calculated based on a signal from the crank position sensor 140 and is input from the engine ECU 24 by communication. Further, 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. It was supposed to be. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 and the remaining capacity (SOC) of the battery 50 and input from the battery ECU 52 by communication. The voltage Vb between the terminals of the battery 50 is detected by the voltage sensor 50a and input from the battery ECU 52 by communication.

  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. 5 shows an example of the required torque setting map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the 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, the set required power Pe * is compared with a threshold value Pref for starting motor travel (step S120), and when the required power Pe * is equal to or less than the threshold value Pref, the operation of the engine 22 is stopped and the motor MG2 is started. It is determined that the engine 22 and the motors MG1 and MG2 should be controlled in the motor operation mode that outputs the motive power, and then it is checked whether or not the engine 22 is stopped (step S130). When the engine 22 is in operation, it is determined that the engine 22 should be stopped, a stop instruction is transmitted to the engine ECU 24 to stop the engine 22 (step S140), and a value 0 is added to the torque command Tm1 * of the motor MG1. Is set (step S180). The engine ECU 24 that has received the stop instruction transmitted in the process of step S140 executes a process of stopping the fuel injection control and the ignition control in the engine 22.

  On the other hand, when the engine 22 is stopped, it is checked whether or not the engine 22 is under engine start control described later (step S150). When the engine 22 is not under start control, a voltage threshold value Vref is set as a threshold value for the voltage across the terminals of the battery 50 that determines whether to start the engine 22 based on the vehicle speed V and the remaining capacity SOC (step S160). ). A method for setting the voltage threshold value Vref will be described later.

  Subsequently, the inter-terminal voltage Vb of the battery 50 is compared with the voltage threshold value Vref (step S170), and it is determined whether or not a motor running condition for running while continuing control in another motor operation mode is satisfied. (Step S175). Here, the motor running condition includes a condition such that the remaining capacity of the battery 50 is higher than a remaining capacity threshold value capable of continuing the SOC motor running. When the voltage Vb between the terminals of the battery 50 is equal to or higher than the voltage threshold Vref and the motor travel condition is satisfied (steps S170 and S175), it is determined that the motor travel can be continued, and the torque command Tm1 * of the motor MG1 is set. A value of 0 is set (step S180).

  When the torque command Tm1 * of the motor MG1 is thus set, a value obtained by dividing the required torque Tr * by the gear ratio Gr of the reduction gear 35 is set as a temporary motor torque Tm2tmp, which is a temporary value of torque to be output from the motor MG2. 1) (Step S190).

  Tm2tmp = Tr * / Gr (1)

  When the target rotational speed Nm1 * of the motor MG1 and the torque command Tm1 * are calculated, the motor MG1 obtained by multiplying the input / output limits Win, Wout of the battery 50 and the set torque command Tm1 * by the current rotational speed Nm1 of the motor MG1. The torque limits Tm2min and Tm2max as upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the power consumption (generated power) by the rotation speed Nm2 of the motor MG2 are expressed by the following equations (2) and ( 3) (step S280), and the calculated temporary motor torque Tm2tmp is limited by the torque limits Tm2min and Tm2max using equation (4) to set the torque command Tm2 * of the motor MG2 (step S290).

Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (2)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (3)
Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (4)

  When the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are thus set, the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S300), and the drive control routine is terminated. Receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. . By such control, when the motor running condition is satisfied and the voltage Vb between the terminals of the battery 50 is equal to or higher than the voltage threshold Vref, the input / output limits Win and Wout of the battery 50 from the motor MG2 are stopped in a state where the operation of the engine 22 is stopped. In this range, the required torque Tr * can be output to the ring gear shaft 32a as the drive shaft to travel.

  Thus, during the control in the motor operation mode, when the voltage Vb between the terminals of the battery 50 becomes less than the voltage threshold Vref (step S170) or the motor running condition is not satisfied (step S175), the engine When it is determined that the engine 22 needs to be started, engine start control for starting the engine 22 is executed. In the engine start control, first, a torque command Tm1 * of the motor MG1 is set based on the torque map of the engine 22 and the elapsed time t from the start of the engine 22 start. (Step S200). FIG. 6 shows an example of a torque map set in the torque command Tm1 * of the motor MG1 when the engine 22 is started and an example of a change in the rotational speed Ne of the engine 22. In the torque map of the embodiment, a relatively large torque is set in the torque command Tm1 * using rate processing immediately after the time t11 when the start instruction of the engine 22 is given, and the rotational speed Ne of the engine 22 is rapidly increased. The engine 22 can be stably motored at the ignition start rotational speed Nref or more at a time t12 after the time when the rotational speed Ne of the engine 22 has passed the resonance rotational speed band or a time necessary for passing through the resonant rotational speed band. The torque that can be generated is set in the torque command Tm1 * to reduce the power consumption and the reaction force in the ring gear shaft 32a as the drive shaft. Then, the torque command Tm1 * is set to 0 using rate processing from the time t13 when the rotational speed Ne of the engine 22 reaches the rotational speed Nref, and the torque for power generation is torqued from the time t15 when the complete explosion of the engine 22 is determined. Set to command Tm1 *. Here, the ignition start speed Nref is the speed at which the fuel injection control and the ignition control of the engine 22 are started.

  When the torque command Tm1 * of the motor MG1 is set in this way, the rotational speed Ne of the engine 22 is compared with the ignition start rotational speed Nref (step S210). When the rotational speed Ne is less than the ignition start rotational speed Nref, the inertia torque Ti associated with the rotational speed change of the motor MG1 is subtracted from the required torque Tr * and the set torque command Tm1 * and divided by the gear ratio ρ of the power distribution and integration mechanism 30. A temporary torque Tm2tmp, which is a temporary value of the torque to be output from the motor MG2, is calculated by dividing the sum of the torque by the gear ratio Gr of the reduction gear 35 by the following equation (5) (step S230), Torque command Tm2 * of motor MG2 is set by limiting calculated temporary torque Tm2tmp with torque limits Tm2min and Tm2max according to the aforementioned equation (4) (steps S280 and S290). Here, equation (5) can be easily derived from the alignment chart of FIG. The torque indicated by the two thick arrows on the R axis in the nomograph of FIG. 7 is the torque that is obtained by subtracting the inertia torque Ti from the torque output from the motor MG1 and the torque that is applied to the ring gear shaft 32a and the output from the motor MG2. Torque Tm2 * applied to the ring gear shaft 32a via the reduction gear 35.

  Tm2tmp = (Tr * + (Tm1 * -Ti) / ρ) / Gr (5)

  When the temporary motor torque Tm2tmp is set, the torque command Tm2 * of the motor MG2 that outputs the required torque Tr * to the ring gear shaft 32a within the range of the input / output limits Win and Wout of the battery 50 is set and transmitted to the motor ECU 40. (Steps S280 to S300) While this routine is ended and control for starting the engine 22 is thus performed (Step S150), the processes of S100 to S130, S150, Steps S200 to S230, and S280 to S300 are repeated. By such control, the motor 22 is motored by the motor MG1, and within the range of the input / output limits Win and Wout of the battery 50, the required torque Tr * is output to the ring gear shaft 32a serving as the drive shaft.

  When the engine 22 is motored and the engine speed Ne is equal to or greater than the ignition start engine speed Nref (step S210), a control signal is transmitted to the engine ECU 24 to start fuel injection control and ignition control in the engine 22. (Step S220) Based on the set torque command Tm1 *, the torque command Tm2 * of the motor MG2 is set so that the required torque Tr * is output to the ring gear shaft 32a within the range of the input / output limits Win and Wout of the battery 50. Are transmitted to the motor ECU 40 (steps S230, S280 to S300), and this routine is terminated. Under such control, the engine 22 is motored by the motor MG1 to start the engine 22, and the required torque Tr * is output to the ring gear shaft 32a as the drive shaft within the range of the input / output limits Win and Wout of the battery 50. To do.

  Here, a method of setting the voltage threshold value Vref in the process of step S160 will be described. For the voltage threshold Vref, the relationship between the vehicle speed V, the remaining capacity SOC of the battery 50, and the voltage threshold Vref is determined in advance and stored in the ROM 24b and the data 74 as a voltage threshold setting map. When the remaining capacity SOC is given, the corresponding voltage threshold value Vref is derived and set from the stored map. FIG. 8 shows an example of a voltage threshold setting map. The voltage threshold Vref is a voltage amount estimated to be the amount of decrease in the voltage between the terminals of the battery 50 from the start of motoring of the engine 22 to the end of the start of the engine 22 from the lower limit voltage at which power cannot be extracted from the battery 50. As shown in the figure, the voltage is set so as to decrease as the remaining capacity SOC increases and decreases as the vehicle speed V increases. For example, the lower limit voltage of the battery 50 is 200 [V ] Is set in a range of about 260 [V] to 290 [V]. That is, in the voltage threshold setting map, the amount of decrease in the voltage between the terminals of the battery 50 when starting the engine 22 estimated from the vehicle speed V and the remaining capacity SOC is obtained in advance, and the engine is based on the obtained amount of reduction. Thus, the vehicle speed V, the remaining capacity SOC, and the voltage threshold value Vref are related so that the voltage across the terminals of the battery 50 does not fall below the lower limit voltage when the engine 22 is started. Here, the voltage threshold value Vref is set to decrease as the remaining capacity SOC increases. The reason is that the motor 22 starts motoring after the engine 22 starts motoring as the remaining capacity SOC increases. Therefore, even if the voltage threshold value Vref is set smaller than when the remaining capacity SOC is small, the terminal of the battery 50 is estimated. This is because the inter-voltage Vb does not become lower than the lower limit voltage. The reason why the voltage threshold value Vref is set to decrease as the vehicle speed V increases is based on the following reason. As illustrated in FIG. 9, when the vehicle speed V is relatively high, the motor MG <b> 2 consumes power while generating power with the motor MG <b> 1. In such a state, when the torque output from the motor MG2 is considered as the temporary motor torque Tm2tmp of the above-described equation (5), the power consumption (Tm1 · Nm1, motor MMG1) is equal to the power consumption (Tm2tmp · Nm2) in the motor MG2. The power consumption P of the entire vehicle including a negative value when considering the case where MG1 is generating power is expressed by the following equation (6). Here, as shown in FIG. 5, the required torque Tr * is set so as to decrease as the vehicle speed V becomes higher if the accelerator opening degree Acc is constant, and the torque command Tm1 * is the map illustrated in FIG. 7 regardless of the vehicle speed V. The inertia torque Ti is substantially constant regardless of the vehicle speed V. Accordingly, the power consumption P is estimated to be smaller as the vehicle speed V increases as a whole, and the motor 22 starts motoring after the engine 22 starts motoring as the vehicle speed V when starting the motoring of the engine 22 increases. Since the amount of decrease in the inter-terminal voltage Vb of the battery 50 until completion is estimated to be small, the inter-terminal voltage Vb of the battery 50 is the lower limit even if the voltage threshold Vref is set smaller than when the vehicle speed V is low. The voltage does not fall below. In this way, the engine 22 can be started at a more appropriate timing by setting the voltage threshold Vref based on the amount of decrease in the voltage between the terminals of the battery 50 estimated based on the vehicle speed V and the remaining capacity SOC. it can.

  P = (Tr * -Ti / ρ) / Gr ・ Nm2 + Tm1 * / ρ ・ Ne ・ (1 + ρ) (6)

  When the required power Pe * is larger than the threshold value Pref (step S120), it is necessary to control the operation of the engine 22 and the motors MG1 and MG2 in the torque conversion operation mode and the charge / discharge operation mode in which the power from the engine 22 is used. If the engine 22 is not operated (step S240), the processes of steps S200 to S230 and S280 to S300 are executed to start the engine 22, and when the engine 22 is operating, the set required power Based on Pe *, a target rotational speed Ne * and a target torque Te * are set as operating points for efficiently operating the engine 22 (step S250). Subsequently, the target rotational speed Ne * of the engine 22 and the motor MG2 are set. Using the rotational speed Nm2 and the gear ratio ρ of the power distribution and integration mechanism 30, the following equation (7) The motor MG1 calculates the target rotational speed Nm1 * of the motor MG1 and causes the motor MG1 to rotate at the rotational speed Nm1 * according to the equation (8) based on the calculated target rotational speed Nm1 * and the input rotational speed Nm1 of the motor MG1. Torque command Tm1 * as a torque to be output from is calculated (step S270). FIG. 10 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 when traveling with the power output from the engine 22. FIG. Expression (8) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (8), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / ρ (7)
Tm1 * = ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (8)

  When the target rotational speed Nm1 * and the torque command Tm1 * of the motor MG1 are thus calculated, the reduction gear Gr is obtained by adding the torque command Tm1 * of the motor MG1 divided by the gear ratio ρ of the power split mechanism 30 to the required torque Tr *. Is obtained by the following equation (9) and set as the temporary motor torque Tm2tmp (step S270). Here, Expression (9) can be easily derived from the alignment chart illustrated in FIG. Thus, when the temporary motor torque Tm2tmp is set, the torque command Tm2 * of the motor MG2 in which the required torque Tr * is output to the ring gear shaft 32a within the range of the input / output limits Win and Wout of the battery 50 is set (step S280, S290), the set target rotational speed Ne * and target torque Te * of the engine 22 are transmitted to the engine ECU 24, and the set torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S300). This routine ends. 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. With this control, after the engine 22 is started, the engine 22 is efficiently operated within the range of the input / output limits Win and Wout of the battery 50, and the required torque Tr * is output to the ring gear shaft 32a as the drive shaft. And can travel.

  Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (9)

  According to the hybrid vehicle 20 of the embodiment described above, when starting the engine that has been stopped, the engine 22 starts to start after the motoring of the engine 22 is started based on the vehicle speed V and the remaining capacity SOC. The voltage threshold Vref as a threshold for starting the engine 22 is set by estimating the amount of decrease in the voltage Vb between the terminals of the battery 50 until the engine 22 is started (until the operation of the engine 22 starts), and the voltage Vref between the terminals of the battery 50 is set. Is less than the set voltage threshold Vref, the engine 22 is motored and started, so that the voltage across the terminals of the battery 50 can be suppressed from falling below the lower limit voltage and the engine can be started at a more appropriate timing. .

  In the hybrid vehicle 20 of the embodiment, the voltage threshold is set by estimating the amount of decrease in the voltage between the terminals of the battery 50 based on the vehicle speed V and the remaining capacity SOC, but based on the vehicle speed V and the remaining capacity SOC. Thus, the amount of decrease in the voltage between the terminals of the battery 50 is not limited to the one that estimates the amount of decrease in the voltage between the terminals. Or may be estimated. Further, as long as the amount of decrease in the voltage of the battery 50 can be estimated, the degree of decrease in the voltage between the terminals of the battery 50 may be estimated based on any state amount. It is good also as what estimates the fall amount of the battery 50 based on an open circuit voltage, accelerator opening degree Acc, etc. In this case, the amount of decrease in the voltage between the terminals of the battery 50 increases as the temperature of the battery 50 increases, increases as the open circuit voltage of the battery 50 increases, and increases as the accelerator opening Acc increases and the required torque Tr * increases. Since it is estimated that the voltage tends to tend, it is desirable that the voltage threshold Vref be set to decrease as the temperature of the battery 50 increases, the open circuit voltage of the battery 50 increases, or the accelerator opening decreases. .

  In the hybrid vehicle 20 of the embodiment, the amount of decrease in the voltage between the terminals of the battery 50 is obtained in advance based on the vehicle speed V and the remaining capacity SOC, but the amount of reduction is not limited to that obtained in advance. Alternatively, the degree of decrease in the terminal voltage of the battery 50 may be estimated based on the tendency of the terminal voltage of the battery 50 to decrease with respect to the vehicle speed V and the remaining capacity SOC.

  In the hybrid vehicle 20 of the embodiment, the voltage threshold value Vref is set based on the vehicle speed V and the remaining capacity SOC using the voltage threshold value setting map illustrated in FIG. 8, but every time the engine 22 is started. The lower limit voltage of the battery 50 was learned by learning the vehicle speed V, the remaining capacity SOC at the time of starting the engine 22 and the voltage drop amount of the voltage across the terminals of the battery 50 from when the engine 22 was started to when the engine was started. If the voltage drop amount is added as the voltage threshold value Vref corresponding to the vehicle speed V and the remaining capacity SOC at the time of starting the engine 22 illustrated in FIG. 8 as an example, the voltage threshold value Vref can be set more appropriately. it can.

  In the hybrid vehicle 20 of the embodiment, when the operation of the engine 22 is stopped and the motor travels with the power from the motor MG2, when the voltage Vb between the terminals of the battery 50 is equal to or higher than the threshold value Vref, the motor travel is continued. The control for starting the engine 22 is executed when the voltage Vb between the terminals of the battery 50 is less than the threshold value Vref. However, the execution of such control is not limited to when the motor is running. Such control may be executed when the operation of 22 is stopped but the vehicle is not running using the power from the motor MG2. In this case, when the voltage Vb between the terminals of the battery 50 is equal to or higher than the threshold value Vref, the operation of the engine 22 is stopped, and when the voltage Vb between the terminals of the battery 50 is less than the threshold value Vref, the engine 22 is started. It may be executed.

  In the hybrid vehicle 20 of the embodiment, the engine 22 is motored using the motor MG1, but a starter motor dedicated to starting the engine 22 is provided separately from the motor MG1, and the engine is started using such a starter motor. It may be a thing.

  In the hybrid vehicle 20 of the embodiment, the motor MG2 is attached to the ring gear shaft 32a as the drive shaft via the reduction gear 35. However, the motor MG2 may be directly attached to the ring gear shaft 32a, or Instead, the motor MG2 may be attached to the ring gear shaft 32a via a transmission such as a 2-speed, 3-speed, or 4-speed.

  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 connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 11) 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 of 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, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  In the embodiment, the present invention is applied to a vehicle including two motors and an engine. However, the present invention can be applied to any vehicle as long as the engine and the motor are mounted and the vehicle can travel using at least power from the motor. Good.

  Moreover, it is not limited to what is applied to such a hybrid vehicle, It is good also as a form of the control method of such a vehicle.

  Here, 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 MG2 corresponds to an “electric motor”, the power distribution and integration mechanism 30 and the motor MG1 correspond to “engine starting means”, and the battery 50 corresponds to “power storage means”. And the voltage sensor 50a corresponds to the “voltage detection means”, and the hybrid electronic control unit executes the process of step S160 for determining the amount of decrease in the voltage across the battery 50 based on the vehicle speed V and the remaining capacity SOC. 70 corresponds to “voltage drop estimation means”, and the hybrid electronic control unit 70 that executes the process of step S160 for setting the voltage threshold Vref based on the estimated amount of decrease in the voltage across the battery 50 is “threshold value”. It is equivalent to “setting means”, and when the engine 22 is stopped, the voltage Vb between the terminals of the battery 50 is higher than the threshold value Vref. In order to start the engine 22 when the voltage Vb between the terminals of the battery 50 reaches less than the threshold value Vref when the engine 22 is stopped. Steps S130, S150 to S170, S200 to S230 for setting the torque for motoring 22 to the torque command Tm1 * of the motor MG1 and transmitting it to the motor ECU 40, and sending the fuel injection control instruction and ignition control instruction to the engine ECU 24, The hybrid electronic control unit 70 that executes the processing of S280 to S300, the engine ECU 24 that executes fuel injection control and ignition control in the engine 22, and the motor EUC 40 that controls the inverter 41 so that the motor MG1 is driven by the torque command Tm1 *. "organ Corresponding to the dynamic control means ". Further, when the engine 22 is stopped, the torque command Tm1 of the motors MG1 and MG2 is output so that the torque based on the required torque Tr * is output from the motor MG2 when the voltage Vb between the terminals of the battery 50 is equal to or higher than the threshold value Vref. When *, Tm2 * are set and transmitted to the motor ECU 40, the processing at steps S180, S190, steps S280 to S300, or when the inter-terminal voltage Vb of the battery 50 is less than the threshold value Vref when the engine 22 is stopped. The hybrid electronic control unit 70 for executing the processes of steps S230 and S280 to S300 for setting the torque command Tm2 * of the motor MG2 and transmitting it to the motor ECU 40 so that the torque based on the requested torque Tr * is output from the motor MG2. Motor MG2 is driven by command Tm2 * Yo corresponding to both motor EUC40 for controlling the inverter 42 "engine start control means". Further, every time the engine 22 is started, learning is performed by detecting the vehicle speed V, the remaining capacity SOC at the time of starting the engine 22, and the voltage drop amount of the voltage across the terminals of the battery 50 from the start of the engine 22 to the end of the start. The hybrid electronic control unit 70 corresponds to “learning means”. Furthermore, the power distribution and integration mechanism 30 and the motor MG1 correspond to “power power input / output means”. The power distribution and integration mechanism 30 corresponds to “three-axis power input / output means”, and the motor MG1 corresponds to “generator”. Further, the counter-rotor motor 230 also corresponds to “power power input / output means”. 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 “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 power to the drive shaft, such as an induction motor. . The “engine starting means” is not limited to the combination of the power distribution and integration mechanism 30 and the motor MG1, but may be used for starting an internal combustion engine such as a starter motor that motors a crankshaft of the engine. It does not matter as long as it is anything. The “power storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it can exchange electric power with the motor and the engine starting means, such as a capacitor. The “voltage detection means” is not limited to the voltage sensor 50a, and any voltage detection means may be used as long as it detects the voltage across the terminals of the power storage means. The “voltage drop degree estimation means” is not limited to the one that estimates the reduction amount of the terminal voltage of the battery 50 based on the vehicle speed V or the remaining capacity SOC, but the terminal voltage drop based only on the vehicle speed V. Estimating the amount of decrease in voltage between terminals based only on the amount of estimation or remaining capacity SOC, estimating the amount of decrease in voltage between terminals based on the accelerator opening Acc, the open voltage of the battery 50, and the temperature of the battery 50 Any device may be used as long as it can estimate the degree of decrease in the voltage between terminals of the power storage means. The “threshold setting means” may be anything as long as it sets a voltage threshold for starting the internal combustion engine based on the estimated decrease in the voltage between the terminals. The “engine start 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, as the “engine start control means”, when the engine 22 is stopped, when the voltage Vb between the terminals of the battery 50 is equal to or higher than the threshold value Vref, the state in which the operation of the engine 22 is stopped is continued. It is not limited to starting the engine 22 when the voltage Vb between the terminals of the battery 50 reaches less than the threshold value Vref when the engine 22 is stopped and the operation of the engine 22 is stopped. When the operation is stopped, the internal combustion engine and the engine starting means are controlled and detected so as to continue the operation stop of the internal combustion engine until the detected voltage between the terminals becomes less than the set voltage threshold value. Any device that controls the internal combustion engine and the engine starting means so that the internal combustion engine is started when the terminal voltage is less than the set voltage threshold value. It may be as. The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of generator such as an induction motor that can input and output power. The “three-axis power input / output means” is not limited to the power distribution / integration mechanism 30 described above, but a mechanism using a double pinion planetary gear mechanism or a combination of a plurality of planetary gear mechanisms and four or more shafts. Or a differential gear such as a differential gear that is different from the planetary gear, such as a drive shaft, an output shaft, and a rotating shaft of a generator. As long as the power is input / output to / from the remaining shafts based on the power input / output to / from the shafts, any device may be used. 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 is the same as that of the embodiment described in the column of means for solving the problems. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problems. In other words, the interpretation of the invention described in the column of means for solving the problem 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 problem. It is only a specific example.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the automobile manufacturing industry and the like.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. It is explanatory drawing which shows an example of the relationship between the battery temperature Tb in the battery 50, and input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the relationship between the remaining capacity (SOC) of the battery 50, and the correction coefficient of input / output restrictions Win and Wout. It is a flowchart which shows an example of the drive control routine performed by the electronic control unit for hybrids 70 of an Example. 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 torque map set to the torque command Tm1 * of motor MG1 at the time of engine 22 start, and an example of the mode of the rotation speed Ne of the engine 22. 4 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of the power distribution and integration mechanism 30 when the engine 22 is started. FIG. It is explanatory drawing which shows an example of the voltage threshold value setting map. It is explanatory drawing which shows an example of the collinear diagram which shows the dynamic relationship of the rotation speed and torque in the rotation element of the power distribution integration mechanism 30 when the engine 22 is started in the state where the vehicle speed V is comparatively high. FIG. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of a power distribution and integration mechanism 30 when traveling with power output from an engine 22; 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.

Explanation of symbols

  20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a CPU, 24b ROM, 24c RAM, 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 rotational position detection sensor, 50 battery, 50a voltage sensor, 51 temperature sensor, 52 Electronic control unit for battery (battery ECU), 54 electric power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 electronic control unit for hybrid, 2 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, 122 air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purification device, 136, Throttle motor, 138 Ignition coil, 140 Crank position sensor, 142 Water temperature sensor, 143 Pressure sensor, 144 Cam position sensor, 146 throttle valve position sensor, 148 air flow meter, 149 temperature sensor, 150 variable valve timing mechanism, 230 Counter rotor motor, 232 Inner rotor 234 Outer rotor, MG1, MG2 motor.

Claims (12)

A vehicle equipped with an internal combustion engine and an electric motor and capable of traveling using at least power from the electric motor,
Engine starting means used for starting the internal combustion engine;
Power storage means capable of exchanging electric power with the electric motor and the engine starting means;
Voltage detecting means for detecting a voltage between terminals of the power storage means;
A voltage drop degree estimating means for estimating the drop degree of the voltage between the terminals of the power storage means;
Threshold setting means for setting a threshold for voltage for starting the internal combustion engine based on the estimated degree of decrease in the inter-terminal voltage;
The internal combustion engine and the engine so as to continue the shutdown of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold when the internal combustion engine is in a shutdown state. Engine starting control for controlling the internal combustion engine and the engine starting means so as to start the internal combustion engine when the detected inter-terminal voltage reaches less than the set voltage threshold value. Means,
A vehicle comprising:   2. The vehicle according to claim 1, wherein the voltage drop estimation unit is a unit that estimates a reduction degree of the voltage between the terminals based on at least one of a vehicle speed, a state of the power storage unit, and an accelerator opening.   The voltage drop estimation means determines the degree of reduction of the voltage between the terminals based on at least one of the remaining capacity of the electricity storage means, the temperature of the electricity storage means, and the open voltage of the electricity storage means as the state of the electricity storage means. The vehicle according to claim 2, which is means for estimating. The vehicle according to claim 3,
The voltage drop estimation means estimates the degree of decrease in the voltage between the terminals in a tendency to decrease as the remaining capacity of the power storage means increases,
The threshold value setting means is a means for setting the voltage threshold value so as to decrease as the estimated decrease in the terminal voltage decreases. The vehicle according to any one of claims 1 to 4,
The voltage drop estimation means is a means for estimating a reduction degree of the voltage between the terminals in a tendency to decrease as the accelerator opening decreases.
The threshold value setting means is a means for setting the voltage threshold value so as to decrease as the estimated decrease in the terminal voltage decreases.   The engine start control means sets the detected inter-terminal voltage when traveling in a motor traveling mode in which the internal combustion engine is stopped while traveling using power from the electric motor. The internal combustion engine, the engine starting means, and the electric motor are controlled so that traveling in the motor traveling mode is continued until the voltage threshold value is less than the threshold value for voltage, and the detected inter-terminal voltage is set for the set voltage. The vehicle according to any one of claims 1 to 5, which is means for controlling the internal combustion engine, the engine starting means, and the electric motor so that the internal combustion engine is started and travels when the value is less than a threshold value. The vehicle according to claim 1,
Learning means for learning a voltage drop amount of the inter-terminal voltage when the internal combustion engine is started,
The voltage drop estimating means is a means for estimating a reduction degree of the voltage between the terminals based on the learned voltage drop amount. A vehicle according to any one of claims 1 to 7,
The engine starting means is means capable of motoring the output shaft of the internal combustion engine,
The engine start control means is a means for controlling the engine start means so that the output shaft of the internal combustion engine is motored when starting the internal combustion engine. The vehicle according to claim 8, wherein
The engine starting means is connected to a drive shaft connected to an axle and an output shaft of the internal combustion engine, and is connected to an output shaft of the internal combustion engine with input / output of power to the drive shaft by input / output of electric power and power. It is a means comprising electric power input / output means capable of inputting / outputting power,
The electric motor is an electric motor that inputs and outputs power to the drive shaft.   The power motive power input / output means is connected to the output shaft of the internal combustion engine, the drive shaft, and a third shaft, and the remaining one shaft based on the power input / output to / from any two of the three shafts 10. The vehicle according to claim 9, further comprising: a three-shaft power input / output means for inputting / outputting power to / from the power generator and a generator for inputting / outputting power to / from the third shaft. The vehicle according to claim 10,
A required driving force setting means for setting a required driving force required for the drive shaft;
The voltage drop estimating means is a means for estimating the degree of decrease in the voltage between the terminals in a tendency to decrease as the vehicle speed increases.
The threshold value setting means is a means for setting the threshold value for voltage in a tendency to decrease as the estimated degree of decrease in the terminal voltage decreases.
The engine start control means continues the operation stop of the internal combustion engine until the detected inter-terminal voltage reaches less than the set voltage threshold, and a driving force based on the set required driving force is The internal combustion engine, the generator, and the electric motor are controlled so as to be output to a drive shaft, and when the detected inter-terminal voltage is less than the set voltage threshold, the output shaft of the internal combustion engine is a motor. The driving force output to the drive shaft based on the change in the rotational speed of the generator, the driving force output from the generator to the drive shaft, and the output from the electric motor to the drive shaft Vehicle that controls the internal combustion engine, the generator, and the electric motor so that a driving force based on the set required driving force is output to the driving shaft by a driving force that is the sum of the driving force that is generated . An internal combustion engine and an electric motor are mounted, and an engine starting means used for starting the internal combustion engine, an electric storage means capable of exchanging electric power with the electric motor and the engine starting means, and a voltage between terminals of the electric storage means are detected. A method for controlling a vehicle including a voltage detection means and capable of traveling using at least power from the electric motor,
Estimating the degree of voltage drop between the terminals of the power storage means,
Setting a threshold for voltage for starting the internal combustion engine based on the estimated decrease in the voltage between the terminals,
The internal combustion engine and the engine so as to continue the shutdown of the internal combustion engine until the detected inter-terminal voltage becomes less than the set voltage threshold when the internal combustion engine is in a shutdown state. And controlling the internal combustion engine and the engine starting means so that the internal combustion engine is started when the detected inter-terminal voltage is less than the set voltage threshold value. Method.

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