JP4281750B2 - Vehicle and vehicle control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a torque shock from being generated in a driving shaft with stopping of fuel injection to an internal combustion engine, while not applying incongruent feeling to a driver by a sound of a tooth hammer in a gear mechanism. <P>SOLUTION: In this vehicle with an engine, the first motor and the driving shaft connected to a planetary gear, and with the second motor connected to the driving shaft via a reduction gear, a correction torque Ta for canceling torque fluctuation acting on the driving shaft by fuel cut is set (S240), when the fuel cut is started in the engine, the sum of temporary motor torque Tm2tmp and the correction torque Ta is set as a torque command Tm2* (S210-S230), when a product of the sum of the temporary motor torque Tm2tmp outputted from the second motor and the correction torque Ta, and the temporary motor torque Tm2tmp, does not come to a negative value, and the temporary motor torque Tm2tmp is set as the torque command Tm2* (S270-S300), when getting to the negative value. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a vehicle that travels by power output to an axle, an internal combustion engine that can output power to a drive shaft connected to the axle, an electric motor that can input and output power, and a gear mechanism, and the rotation shaft of the motor and the drive. The present invention relates to a vehicle control method including gear type power transmission means for connecting a shaft and transmitting power between both shafts.

Conventionally, this type of vehicle includes an engine, a planetary gear having a carrier connected to the crankshaft of the engine and a ring gear connected to a drive shaft, a first motor connected to a sun gear of the planetary gear, and a ring gear of the planetary gear. The thing provided with the connected 2nd motor is proposed (for example, refer to patent documents 1). In this vehicle, the torque necessary for canceling the fluctuation of the torque acting on the drive shaft due to the fuel cut to the engine is output from the second motor, thereby suppressing the torque shock that can occur on the drive shaft due to the fuel cut. It is said.
Japanese Patent Laid-Open No. 10-248114

  By the way, in a vehicle of a type in which the rotation shaft and the drive shaft of the second motor are connected by a gear mechanism such as a reduction gear or a transmission, if the torque output from the second motor changes across a value 0, the gear mechanism When rattling, there is a case where rattling noise is generated, which may give the driver and passenger a sense of incongruity. It is also desirable to prevent the driver and passengers from feeling.

  It is an object of the vehicle and the vehicle control method of the present invention to prevent the driver and passengers from feeling uncomfortable with traveling. Another object of the vehicle and the vehicle control method of the present invention is to suppress a torque shock that may occur on the drive shaft due to fuel cut while suppressing gear rattling noise in the gear mechanism.

  The vehicle and the vehicle control method of the present invention employ the following means in order to achieve at least a part of the above object.

The vehicle of the present invention
A vehicle that travels by power output to an axle,
An internal combustion engine capable of outputting power to a drive shaft connected to the axle;
An electric motor that can input and output power;
Gear-type power transmission means for connecting the rotary shaft of the electric motor and the drive shaft by a gear mechanism to transmit power between the two shafts;
Required power setting means for setting required power required for traveling;
The sign of the torque output from the electric motor changes when an attempt is made to correct the torque output from the electric motor by a correction torque for suppressing torque fluctuations acting on the drive shaft by stopping fuel injection to the internal combustion engine. Sign change determining means for determining whether or not,
When the sign change determining means determines that the sign of the torque output from the motor does not change, the target torque to be output from the motor is set based on the set required power and the correction torque, and the sign Target torque setting means for setting a target torque to be output from the electric motor based on the set required power when it is determined by the change determining means that the sign of the torque output from the electric motor is changed;
And a control means for driving and controlling the electric motor based on the set target torque.

  In the vehicle of the present invention, the sign of the torque output from the motor when attempting to correct the torque output from the motor with the correction torque for suppressing the torque fluctuation acting on the drive shaft by stopping the fuel injection to the internal combustion engine. The target torque to be output from the electric motor is set based on the required power and the correction torque required for the drive shaft when it is determined that the sign of the torque output from the electric motor does not change. When it is determined that the sign of the torque output from the electric motor changes, a target torque to be output from the electric motor is set based on the required power, and the electric motor is driven and controlled based on the set target torque. Therefore, it is possible to suppress a torque shock that can occur on the drive shaft due to fuel cut while suppressing gear rattling noise in the gear mechanism. As a result, the driver or the occupant can be prevented from feeling uncomfortable with traveling.

  In such a vehicle of the present invention, the sign change determination means changes the sign of the torque output from the motor when attempting to correct the torque output from the motor by the correction torque based on the set required power. It may be a means for determining whether or not to perform, and includes an accelerator operation detecting means for detecting an accelerator operation, and a vehicle speed detecting means for detecting a vehicle speed, and the required power setting means includes the detection The sign change determination means corrects the torque output from the electric motor based on the detected vehicle speed based on the detected vehicle speed. It may be a means for determining whether or not the sign of the torque output from the electric motor changes when an attempt is made. In the latter case, the torque output from the motor is corrected by the correction torque based on the vehicle speed V in consideration of the fact that the fuel injection to the internal combustion engine is normally stopped when the accelerator off or the operation in the vicinity thereof is detected. It is possible to determine whether or not the sign of the torque output from the electric motor changes when an attempt is made. In the vehicle of these aspects of the present invention, the rotation state detection means for detecting the rotation state of the internal combustion engine, and the correction torque setting means for setting the correction torque based on the detected rotation state of the internal combustion engine, The sign change determination means further determines whether or not the sign of the torque output from the motor changes when the torque output from the motor is corrected by the correction torque based on the set correction torque. It can also be a means for judging. In this way, even if the correction torque is changed according to the rotation state of the internal combustion engine, whether or not the sign of the torque output from the motor changes when the torque output from the motor is corrected by the correction torque is determined. More accurate determination can be made.

  The vehicle according to the present invention further includes a noise level detection unit that detects a level of noise accompanying traveling, and the target torque setting unit is configured to detect the noise level when the detected noise level is equal to or higher than a predetermined level. Even when it is determined that the sign of the torque output from the electric motor changes, the target torque may be set based on the set required power and the correction torque. When the level of noise associated with driving is large, the rattling noise generated in the gear mechanism is masked by the noise even when the sign of the torque output from the motor changes, so the driver and passengers feel a sense of discomfort due to the rattling noise in the gear mechanism. Torque shock that can occur in the drive shaft due to fuel cut without being applied can be suppressed. In this case, the noise level detection means may include vehicle speed detection means for detecting the vehicle speed, and may be a means for setting the noise level based on the detected vehicle speed. By doing so, it is possible to detect noise associated with traveling by simpler processing.

  Furthermore, in the vehicle of the present invention, electric power that is connected to the output shaft of the internal combustion engine and the drive shaft, and that can output at least part of the power from the internal combustion engine to the drive shaft by input and output of electric power and power. Input / output means may be provided. In this case, the power / power input / output means is connected to three shafts of the output shaft, the drive shaft, and the third shaft of the internal combustion engine, and is used for power input / output to any two of the three shafts. 3 axis type power input / output means for inputting / outputting power to / from the remaining one shaft, and a generator capable of inputting / outputting power to / from the third shaft. The output means has a first rotor connected to the output shaft of the internal combustion engine and a second rotor connected to the drive shaft, and the first rotor and the second rotor. It is also possible to use a counter-rotor motor that relatively rotates the first rotor and the second rotor by electromagnetic action.

The vehicle control method of the present invention includes:
An internal combustion engine that can output power to a drive shaft connected to an axle, an electric motor that can input and output power, and a gear mechanism that connects the rotating shaft of the motor and the drive shaft to transmit power between the two shafts. A vehicle-type power transmission means for performing vehicle control,
(A) Set the required power required for traveling,
(B) Sign of torque output from the motor when correcting torque output from the motor by correction torque for suppressing torque fluctuations acting on the drive shaft by stopping fuel injection to the internal combustion engine Determine whether or not
(C) When it is determined in step (b) that the sign of the torque output from the motor does not change, a target torque to be output from the motor is set based on the set required power and the correction torque. , When it is determined in step (b) that the sign of the torque output from the electric motor changes, a target torque to be output from the electric motor is set based on the set required power,
(E) The gist is to drive and control the electric motor based on the set target torque.

  According to this vehicle control method of the present invention, when the torque output from the motor is corrected by the correction torque for suppressing the torque fluctuation acting on the drive shaft by stopping the fuel injection to the internal combustion engine, the motor It is determined whether or not the sign of the torque to be output changes, and when it is determined that the sign of the torque to be output from the motor does not change, it should be output from the motor based on the required power required for the drive shaft and the correction torque A target torque is set, and when it is determined that the sign of the torque output from the electric motor changes, a target torque to be output from the electric motor is set based on the required power, and the electric motor is driven and controlled based on the set target torque. Therefore, it is possible to suppress a torque shock that can occur on the drive shaft due to fuel cut while suppressing gear rattling noise in the gear mechanism. As a result, the driver or the occupant can be prevented from feeling uncomfortable with traveling.

  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 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, a voltage between terminals from a voltage sensor (not shown) 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. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores processing programs, a RAM 76 that temporarily stores data, an input / output port and communication (not shown), and the like. 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 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 hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the fuel cut to the engine 22 is executed 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. A process of inputting data necessary for control, such as Nm2, the rotational speed Ne of the engine 22 and the fuel cut flag Ffc, is executed (step S100). Here, the rotation speed Ne of the engine 22 is calculated based on a signal from a crank position sensor (not shown) attached to the crankshaft 26 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, as the fuel cut flag Ffc, a value set in association with the execution of the fuel cut to the engine 22 and the cancellation thereof is input by the engine ECU 24 by communication. The fuel cut flag Ffc is set to a value of 1 when the engine ECU 24 starts executing a fuel cut on the engine 22, and is set to a value of 0 when the fuel cut is cancelled.

  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 P * required for the vehicle 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. 3 shows an example of the required torque setting map. The required power P * can be calculated as the sum of a value obtained by multiplying the set required torque Tr * by the rotation 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 rotation speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor k, or can be obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35.

  When the required torque Tr * and the required power P * are set, the set required power P * and the threshold value Pref are compared (step S120). Here, the threshold value Pref is determined by the characteristics of the engine 22 and the motor MG2 as a lower limit of a region where power should be output from the engine 22, for example, a region where the engine 22 can be operated efficiently. If it is determined that the required power P * is equal to or greater than the threshold value Pref, the target rotational speed Ne * and the target torque Te * of the engine 22 are set based on the set required power P * (step S130). This setting is performed based on the operation line for efficiently operating the engine 22 and the required power P *. FIG. 4 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 having a constant required power P * (Ne * × Te *).

  Next, using the set target rotational speed Ne *, the rotational speed Nr (Nm2 / Gr) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the target rotational speed Nm1 of the motor MG1 is given by the following equation (1). * And a torque command Tm1 * of the motor MG1 is calculated by the equation (2) based on the calculated target rotational speed Nm1 * and the current rotational speed Nm1 (step S140). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 5 is a collinear diagram showing a dynamic relationship between the number of rotations and torque in the rotating elements of the power distribution and integration mechanism 30. 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. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “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 / (Gr ・ ρ) (1)
Tm1 * = previous Tm1 * + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (2)

  When the target rotational speed Nm1 * and the torque command Tm1 * of the motor MG1 are calculated, the temporary torque as the torque to be output from the motor MG2 using the required torque Tr *, the torque command Tm1 * and the gear ratio ρ of the power distribution and integration mechanism 30 is calculated. The motor torque Tm2tmp is calculated from the equation (3) (step S150). This equation (3) can be easily derived from the collinear diagram of FIG.

  Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (3)

  If it is determined in step S120 that the required power P * is less than the threshold value Pref, it is determined whether or not the engine 22 is prohibited from being stopped (step S160). In the embodiment, the engine 22 is prohibited from being stopped when the vehicle speed V is in a predetermined low vehicle speed range. The engine 22 is stopped by executing a fuel cut to the engine 22 and outputting a torque in a direction to hold down the rotation of the engine 22 from the motor MG1, but when the vehicle speed V is in the low vehicle speed region, the engine 22 is stopped. This is based on the fact that the driver and passengers can easily feel the vibration of the vehicle caused by the torque pulsation of the engine 22 when the operation is stopped. When the operation stop of the engine 22 is prohibited, the target rotational speed Ne * of the engine 22 is set based on the input vehicle speed V, and the value 0 is set to the target torque Te * (step S170). Based on the number Ne *, the torque command Tm1 * of the motor MG1 is calculated in the aforementioned step S140, and the temporary motor torque command Tm2tmp of the motor MG2 is calculated in the aforementioned step S150. On the other hand, when the operation stop of the engine 22 is not prohibited, a value 0 is set for the target rotational speed Ne * of the engine 22 and a value 0 is set for the target torque Te * (step S180), and a torque command Tm1 for the motor MG1 is set. The value 0 is set to * (step S190), and the temporary motor torque command Tm2tmp of the motor MG2 (the value obtained by dividing the required torque Tr * by the gear ratio Gr because the torque command Tm1 * is 0) is set in step 150 described above. Set.

  When the target rotational speed Ne * and target torque Te * of the engine 22 are set in this way, the torque command Tm1 * of the motor MG1 and the temporary motor torque Tm2tmp of the motor MG2 are set, the value of the execution flag F is checked (step S200). Here, the execution flag F is a flag having, as a value, whether or not torque fluctuations acting on the ring gear shaft 32a as the drive shaft due to the fuel cut of the engine 22 are canceled by the torque from the motor MG2. Is executed for the first time, the value 0 is set by an initialization routine (not shown). When the execution flag F is 0, it is determined whether or not the current value of the fuel cut flag Ffc is 1 and the previous value is 0, that is, whether or not fuel cut is started (step S210). If the current value of the fuel cut flag Ffc is determined to be 0, or if the current value of the fuel cut flag Ffc is determined to be 1 and the previous value is also determined to be 1, the execution flag F is set to 0. (Step S220), the temporary motor torque Tm2tmp calculated in Step S150 is set in the torque command Tm2 * of the motor MG2 (Step S230), and the target rotational speed Ne * and the target torque Te * are sent to the engine ECU 24 to the torque command Tm1 *. , Tm2 * are transmitted to the motor ECU 40 (step S310), and this routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as ignition control. When the engine ECU 24 receives the target torque Te * having a value of 0, the engine ECU 24 appropriately selects whether to perform fuel cut or idling operation on the engine 22 and controls the operation of the engine 22. The value of the fuel cut flag Ffc is set according to the presence or absence of the fuel cut to 22. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * 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 *. To do.

  On the other hand, if it is determined that the current value of the fuel cut flag Ffc is 1 and the previous value is 0, it is determined that fuel cut to the engine 22 has started, and based on the current rotational speed Ne of the input engine 22. The correction torque Ta of the motor MG2 is set (step S240). In a steady state, the sum of the torque that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque that the torque Tm2 that is output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35 is the required torque Tr *. The temporary motor torque Tm2tmp is set so that the temporary motor torque Tm2tmp is output, and the motor MG2 is controlled so that the temporary motor torque Tm2tmp is output. This corresponds to the required torque Tr *, but immediately after the fuel cut to the engine 22 is executed. During the transition, the torque Te output from the engine 22 is abruptly varied due to friction, and this variation acts on the ring gear shaft 32a. The correction torque Ta is set as a torque necessary for canceling the torque fluctuation acting on the ring gear shaft 32a by the fuel cut to the engine 22 by the motor MG2. In the embodiment, the correction torque Ta is obtained in advance in the ROM 74 as a correction torque setting map by previously obtaining the relationship between the rotation speed Ne of the engine 22 and the correction torque Ta, and corresponds to the correction torque Ta given from the map. The correction torque Ta is derived and set. An example of the correction torque setting map is shown in FIG. As shown in the figure, the correction torque Ta is set so as to increase as the rotational speed Ne increases. This is based on the fact that since the friction increases as the rotational speed Ne of the engine 22 increases, the torque fluctuation acting on the ring gear shaft 32a also increases when the fuel cut to the engine 22 is executed.

  When the correction torque Ta is set, whether or not the sum of the set correction torque Ta and the temporary motor torque Tm2tmp calculated in step S150 and the temporary motor torque Tm2tmp is a negative value, that is, the temporary motor torque Tm2tmp. It is determined whether or not the sign changes from the temporary motor torque Tm2tmp when the correction torque Ta is added to (step S250). In the embodiment, since the motor MG2 is attached to the ring gear shaft 32a via the reduction gear 35, if the sign of the torque output from the motor MG2 changes, the reduction gear 35 is rattled, and the driver is driven by the tooth strike. And rattling noises that make the passenger feel uncomfortable. Therefore, this determination is performed to determine whether or not a rattling sound is generated in the reduction gear 35 when an attempt is made to cancel the torque fluctuation acting on the ring gear shaft 32a due to the fuel cut of the engine 22 by the torque from the motor MG2. Become.

  When it is determined that the product of the sum of the correction torque Ta and the temporary motor torque Tm2tmp and the temporary motor torque Tm2tmp does not become a negative value, the temporary motor torque Tm2tmp can be calculated even if the correction torque Ta is added to the temporary motor torque Tm2tmp. Since the sign does not change, it is determined that no rattling noise is generated in the reduction gear 35, a value 1 is set to the execution flag F, and a timer (not shown) of the hybrid electronic control unit 70 is started (step S270). When a predetermined time tref, which is predetermined as a period during which torque fluctuation occurs in the shaft 32a, has elapsed (step S280), the correction coefficient K is set based on the elapsed time t after the timer is started (step S290). The correction torque with the correction coefficient K according to the following equation (4) The torque command Tm2 * of the motor MG2 is set by multiplying a by the temporary motor torque Tm2tmp (step S300), and the target rotational speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * are set in the engine ECU 24 It transmits to motor ECU40 (step S310), and this routine is complete | finished. Here, the correction coefficient K corresponds to the torque fluctuation waveform acting on the ring gear shaft 32a due to fuel cut to the engine 22, and the relationship between the elapsed time t from the start of the timer and the correction coefficient K is shown. It is determined in advance and stored in the ROM 74 as a correction coefficient setting map, and when the elapsed time t is given, the corresponding correction coefficient K is derived from the map and set. An example of the correction coefficient setting map is shown in FIG. By such processing, since the execution flag F is determined to be 1 in step S200 thereafter, the temporary motor torque Tm2tmp is corrected based on the correction torque Ta and the correction coefficient K, and the torque command Tm2 * is set. When the predetermined time tref elapses after the process of S300 is repeated and the timer is started (step S280), the execution flag F is reset to 0 (step S220), and the temporary motor torque Tm2tmp is set as the torque command Tm2 * as it is. (Step S230), the command values are transmitted to the engine ECU 24 and the motor ECU 40 (Step S310), and this routine is terminated. Thereby, the torque fluctuation acting on the ring gear shaft 32a due to the fuel cut to the engine 22 is canceled by the torque output from the motor MG2, and no torque shock occurs on the ring gear shaft 32a.

  Tm2 * = Tm2tmp + K ・ Ta (4)

  On the other hand, when it is determined that the product of the sum of the correction torque Ta and the temporary motor torque Tm2tmp and the temporary motor torque Tm2tmp is a negative value, the correction motor Ta is added to the temporary motor torque Tm2tmp, and the temporary motor torque Tm2tmp It is determined that the sign changes and a rattling sound is generated in the reduction gear 35, and the vehicle speed V is compared with a predetermined vehicle speed Vref (step S260). In general, as the vehicle speed V increases, noise associated with traveling increases, and background noise given to the driver and passengers also increases. Therefore, the vehicle speed V can be considered as a detected value or an estimated value of background noise given to a driver or an occupant. The predetermined vehicle speed Vref is a threshold value for determining whether or not the noise accompanying traveling is large enough to mask the rattling noise in the reduction gear 35. When it is determined that the vehicle speed V is less than the predetermined vehicle speed Vref, when the motor MG2 is controlled by the torque command Tm2 * obtained by adding the correction torque Ta to the temporary motor torque Tm2tmp, the torque shock generated in the ring gear shaft 32a due to the fuel cut to the engine 22 is suppressed. Although it is determined that a rattling sound is generated in the reduction gear 35, it is determined that the driver or the passenger will be greatly discomforted, and a value 0 is set in the execution flag F (step S220), and the temporary motor torque Tm2tmp is used as it is. The torque command Tm2 * is set (step S230), each command value is transmitted to the engine ECU 24 and the motor ECU 40 (step S310), and this routine is terminated. This is because when the motor MG2 is controlled by the torque command Tm2 * in which the temporary motor torque Tm2tmp is corrected by the correction torque Ta in order to suppress such torque shock rather than the torque shock generated in the ring gear shaft 32a by the fuel cut to the engine 22. This is based on the experimental confirmation that the generated rattling noise in the reduction gear 35 tends to increase the sense of discomfort given to the driver and the occupant. On the other hand, when it is determined that the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref, a value 1 is set to the execution flag F and a timer is started (step S270), until a predetermined time tref elapses after the timer is started (step S280). ), The product of the correction coefficient K and the correction torque Ta is added to the temporary motor torque Tm2tmp to set a torque command Tm2 * (steps S290 and S300), and the command values are transmitted to the engine ECU 24 and the motor ECU 40 ( Step S310), this routine is finished. This is because even if a rattling noise is generated in the reduction gear 35, the rattling noise is masked by noise accompanying traveling, so that the torque fluctuation acting on the ring gear shaft 32a due to the fuel cut to the engine 22 is canceled by the motor MG2. This is based on the fact that the driver feels less uncomfortable for the driver and passengers.

  FIG. 8 is an explanatory diagram showing the time change of the fuel cut flag Ffc, the torque Te * of the engine 22, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2. As shown in the figure, when the fuel cut flag Ffc changes from 0 to 1 as the fuel cut to the engine 22 starts, the torque fluctuation acting on the ring gear shaft 32a due to the fuel cut is corrected by the motor MG2 using the correction torque Ta. When the sign of the torque output from the motor MG2 changes when attempting to cancel, the torque fluctuation of the ring gear shaft 32a by the motor MG2 is not cancelled. Thereby, although a torque shock occurs in the ring gear shaft 32a due to the fuel cut, it is possible to avoid giving a driver or an occupant a great sense of discomfort due to the rattling noise in the reduction gear 35. Note that when the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref, the rattling noise in the reduction gear 35 is masked by the noise associated with traveling, so that the torque fluctuation of the ring gear shaft 32a is canceled by the motor MG2.

  According to the hybrid vehicle 20 of the embodiment described above, when the motor MG2 uses the correction torque Ta to cancel the torque fluctuation acting on the ring gear shaft 32a as the drive shaft due to the fuel cut to the engine 22, the motor MG2 When the sign of the torque output from the engine changes, the torque fluctuation of the ring gear shaft 32a is not canceled by the motor MG2, so that torque shock to the ring gear shaft 32a due to fuel cut to the engine 22 occurs, but the reduction gear 35 generates rattling noise. It is possible to prevent the driver and the occupant from feeling uncomfortable by avoiding the occurrence of the problem. In addition, when the fuel cut to the engine 22 changes the sign of the torque output from the motor MG2 when torque fluctuation acting on the ring gear shaft 32a as the drive shaft is to be canceled by the motor MG2 using the correction torque Ta. Since the torque fluctuation of the ring gear shaft 32a is canceled by the motor MG2 when the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref, it is possible to further reduce the uncomfortable feeling given to the driver and the occupant when the noise accompanying traveling is large. Of course, when the sign of the torque output from the motor MG2 does not change when the motor MG2 tries to cancel the torque fluctuation acting on the ring gear shaft 32a due to fuel cut, the torque fluctuation of the ring gear shaft 32a is canceled by the motor MG2. Generation of torque shock to the ring gear shaft 32a due to fuel cut can be suppressed.

  In the hybrid vehicle 20 of the embodiment, even when the sum of the temporary motor torque Tm2tmp and the correction torque Ta and the temporary motor torque Tm2tmp multiplied by a negative value is corrected when the vehicle speed V is equal to or higher than the predetermined vehicle speed Vref. The torque command Tm2tmp of the motor MG2 is set by correcting the temporary motor torque Tm2tmp based on the torque Ta, but the sum of the temporary motor torque Tm2tmp and the correction torque Ta and the temporary motor torque Tm2tmp are multiplied. When it becomes a negative value, the temporary motor torque Tm2tmp may be set to the torque command Tm2 * regardless of the vehicle speed V.

  In the hybrid vehicle 20 of the embodiment, it is determined whether or not the sum of the temporary motor torque Tm2tmp and the correction torque Ta and the temporary motor torque Tm2tmp is a negative value to determine whether the reduction gear 35 has a rattling sound. Although the accuracy of the determination is slightly reduced, it is determined whether or not the provisional motor torque Tm2tmp is within a predetermined range near the value 0 on the negative side. It may be determined whether or not a rattling sound is generated.

  In the hybrid vehicle 20 of the embodiment, when the motor MG2 cancels the torque fluctuation that acts on the ring gear shaft 32a due to the fuel cut to the engine 22 based on the temporary motor torque Tm2tmp, does the ratchet noise occur in the reduction gear 35? Whether or not rattling noise is generated in the reduction gear 35 when the motor MG2 tries to cancel the torque fluctuation acting on the ring gear shaft 32a due to the fuel cut to the engine 22 based on the vehicle speed V. It may be determined whether or not. A part of an example of the drive control routine in this case is shown in FIG. In the drive control routine of FIG. 9, when it is determined in step S210 that the current value of the fuel cut flag Ffc is 1 and the previous value is 0, the vehicle speed V is compared with the predetermined vehicle speeds V1 and V2 (step S250b). When it is determined that the vehicle speed V is equal to or higher than the predetermined vehicle speed V1 and equal to or lower than the predetermined vehicle speed V2, a value 0 is set in the execution flag F (step S220), and the temporary motor torque Tm2tmp calculated in step S150 is used as the torque command Tm2 * of the motor MG2. When the vehicle speed V is determined to be less than the predetermined vehicle speed V1 or the vehicle speed V is determined to be greater than the predetermined vehicle speed V2, a value 1 is set to the execution flag F and a timer is started (step S230). S270), the correction torque Ta is set based on the rotational speed Ne of the engine 22 (step S240b), and the timer is started. From until the predetermined time tref has elapsed (step S280), it sets a plus by multiplying the correction torque Ta and a correction coefficient K to tentative motor torque Tm2tmp to the torque command Tm2 * of the motor MG2 (step S300). An example of the relationship between the torque (temporary motor torque Tm2tmp) to be output from the motor MG2 and the vehicle speed V when the accelerator opening Acc is 0% is shown in FIG. As shown in the figure, the predetermined vehicle speed V1 is determined as the vehicle speed when the accelerator opening degree Acc is 0% and the temporary motor torque Tm2tmp shows a value near 0. The predetermined vehicle speed V2 uses the correction torque Ta as the temporary motor. When the torque command Tm2 * is set in addition to the torque Tm2tmp, the vehicle speed is determined as the smaller one of the maximum vehicle speed in the vehicle speed region in which the sign is inverted between the temporary motor torque Tm2tmp and the torque command Tm2 * and the predetermined vehicle speed Vref described above. ing. The predetermined vehicle speed V2 may be determined without considering the predetermined vehicle speed Vref. Further, in the drive control routine of FIG. 9, when the torque command Tm2 * is set by adding the correction torque Ta to the temporary motor torque Tm2tmp by comparing the vehicle speed V with the predetermined vehicle speeds V1 and V2, the gear reduction gear 35 is rattled. Although it is determined whether or not sound is generated, the predetermined vehicle speeds V1 and V2 may be changed based on the rotational speed Ne of the engine 22. In this case, the predetermined vehicle speed V2 may be set so as to increase as the rotational speed Ne of the engine 22 increases.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted and output to the ring gear shaft 32a using the reduction gear 35. However, the present invention is not limited to this, and the power from the motor MG2 is transmitted to the ring gear shaft 32a by a gear mechanism. For example, a transmission that shifts the power from the motor MG2 at two or more shift stages and outputs it to the ring gear shaft 32a may be used.

  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 120 includes an inner rotor 132 connected to the crankshaft 26 of the engine 22 and an outer rotor 134 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 130 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  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. As exemplified in the hybrid vehicle 220, a transmission 230 connected to a crankshaft 26 of the engine 22 and connected to a drive shaft that outputs power to the drive wheels 63a and 63b may be provided.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

  The present invention can be used in the vehicle manufacturing industry.

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 a flowchart which shows an example of the drive control routine performed by the hybrid electronic control unit 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 a mode that an example of the operating line of the engine 22, and target rotational speed Ne * and target torque Te * are set. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30; It is explanatory drawing which shows an example of the map for correction torque setting. It is explanatory drawing which shows an example of the map for a correction coefficient setting. It is explanatory drawing which shows the mode of the time change of the fuel cut flag Ffc, the torque Te * of the engine 22, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2. It is a flowchart which shows a part of drive control routine of a modification. It is explanatory drawing which shows the relationship between the vehicle speed V when the accelerator pedal 83 is turned off, and torque command Tm2 *. 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), 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, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line , 60 gear mechanism, 62 differential gear, 63a, 63b drive 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, 130 Counter rotor motor, 132 Inner rotor 134 Outer rotor, 230 Transmission, MG1, MG2 motor .

Claims (10)

A vehicle that travels by power output to an axle,
An internal combustion engine capable of outputting power to a drive shaft connected to the axle;
An electric motor that can input and output power;
Gear-type power transmission means for connecting the rotary shaft of the electric motor and the drive shaft by a gear mechanism to transmit power between the two shafts;
Required power setting means for setting required power required for traveling;
The sign of the torque output from the electric motor changes when an attempt is made to correct the torque output from the electric motor by a correction torque for suppressing torque fluctuations acting on the drive shaft by stopping fuel injection to the internal combustion engine. Sign change determining means for determining whether or not,
When the sign change determining means determines that the sign of the torque output from the motor does not change, the target torque to be output from the motor is set based on the set required power and the correction torque, and the sign Target torque setting means for setting a target torque to be output from the electric motor based on the set required power when it is determined by the change determining means that the sign of the torque output from the electric motor is changed;
A vehicle comprising: control means for driving and controlling the electric motor based on the set target torque.   The sign change determining means determines whether or not the sign of the torque output from the motor changes when an attempt is made to correct the torque output from the motor with the correction torque based on the set required power. The vehicle according to claim 1, which is means. The vehicle according to claim 1,
An accelerator operation detecting means for detecting an accelerator operation;
Vehicle speed detection means for detecting the vehicle speed;
With
The required power setting means is means for setting required power based on the detected accelerator operation and the detected vehicle speed,
The sign change determining means determines whether or not the sign of the torque output from the motor changes when the torque output from the motor is corrected by the correction torque based on the detected vehicle speed. Is a vehicle. The vehicle according to claim 2 or 3,
Rotation state detection means for detecting the rotation state of the internal combustion engine;
Correction torque setting means for setting the correction torque based on the detected rotational state of the internal combustion engine;
With
The sign change judging means further judges whether or not the sign of the torque output from the motor changes when the torque output from the motor is corrected by the correction torque based on the set correction torque. Vehicle that is means to do. The vehicle according to any one of claims 1 to 4,
A noise level detection means for detecting the level of noise associated with running is provided.
The target torque setting means is set even when the sign change determining means determines that the sign of the torque output from the motor changes when the detected noise level is greater than or equal to a predetermined level. A vehicle which is means for setting the target torque based on required power and the correction torque.   6. The vehicle according to claim 5, wherein the noise level detection means includes vehicle speed detection means for detecting a vehicle speed, and sets the noise level based on the detected vehicle speed.   2. An electric power drive input / output means connected to the output shaft of the internal combustion engine and the drive shaft, and capable of outputting at least part of the power from the internal combustion engine to the drive shaft by input and output of electric power and power. The vehicle according to any one of 6 to 6.   The power power input / output means is connected to three shafts of the output shaft, the drive shaft, and the third shaft of the internal combustion engine, and the residual power based on power input / output to any two of the three shafts. The vehicle according to claim 7, further comprising: a three-axis power input / output unit that inputs / outputs power to / from one axis of the motor, and a generator that can input / output power to the third shaft.   The power drive input / output means has a first rotor connected to the output shaft of the internal combustion engine and a second rotor connected to the drive shaft, and the first rotor and the first rotor 8. The vehicle according to claim 7, wherein the vehicle is a counter-rotor electric motor that relatively rotates the first rotor and the second rotor by electromagnetic action with the second rotor. An internal combustion engine that can output power to a drive shaft connected to an axle, an electric motor that can input and output power, and a gear mechanism that connects the rotating shaft of the motor and the drive shaft to transmit power between the two shafts. A vehicle-type power transmission means for performing vehicle control,
(A) Set the required power required for traveling,
(B) Sign of torque output from the motor when correcting torque output from the motor by correction torque for suppressing torque fluctuations acting on the drive shaft by stopping fuel injection to the internal combustion engine Determine whether or not
(C) When it is determined in step (b) that the sign of the torque output from the motor does not change, a target torque to be output from the motor is set based on the set required power and the correction torque. , When it is determined in step (b) that the sign of the torque output from the electric motor changes, a target torque to be output from the electric motor is set based on the set required power,
(E) A vehicle control method that controls driving of the electric motor based on the set target torque.

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