JP2013086600A - Controller and control method of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel efficiency of an internal combustion engine while suppressing the generation of noise, and to secure running performance satisfactorily in a hybrid vehicle having the internal combustion engine capable of outputting power to one of front and rear wheels, and an electric motor capable of outputting power to the other of the front and rear wheels.SOLUTION: In a case where an operating point of an engine 22, which corresponds to engine request power Pe* on an optimal fuel efficiency operation line, is included in a noise generation area, a target operating point of the engine 22 is set to an operating point (Ne1, Te1) on the optimal fuel efficiency operation line on a lower load side (lower power side) rather than the noise generation area except for a case when output of a motor MG3 should be restricted (Step S270), and a torque command Tm3* of the motor MG3 is set to output the shortfall of a power (value P1) output from the engine 22 to engine requirement power Pe* (step S230).

Description

  The present invention relates to a hybrid including an internal combustion engine capable of outputting power to one of the front wheels and the rear wheel, an electric motor capable of outputting power to the other of the front wheels and the rear wheel, and a power storage device capable of exchanging electric power with the motor. The present invention relates to a vehicle control device and a control method.

  Conventionally, as a hybrid vehicle including a hybrid drive device including an engine, a power split mechanism (planetary gear), and motors MG1 and MG2, an engine efficiency optimum operation line obtained by connecting operating points at which the engine can be operated most efficiently, One that controls an engine using an NV line that defines an allowable value of noise generated in a vehicle is known (for example, see Patent Document 1). In this hybrid vehicle, when it is determined that the operating point of the engine is outside the NV allowable range defined by the NV line, the engine speed is maintained until it falls within the NV allowable range defined by the NV line while maintaining the engine speed. The target torque is corrected to the decreasing side.

  There is also known a hybrid vehicle including the above-described hybrid drive device as a power output source for the front wheels and a motor MG3 capable of outputting power to the rear wheels (see, for example, Patent Document 2). In this hybrid vehicle, the output torque of the motor MG2 is low when the torque output from the motor MG2 of the hybrid drive device is likely to be included in the low torque range that causes the rattling noise of the gear mechanism of the hybrid drive device. The torque command value of the motor MG2 is increased by a predetermined value so that the torque is outside the torque range, and the torque command value of the rear wheel side motor MG3 is decreased by a torque value that cancels the predetermined value. The motors MG2 and MG3 are controlled according to the torque command value without changing the operating point of the engine.

JP 2010-228498 A JP 2008-143462 A

  Although the generation of noise can be suppressed by correcting the target torque of the engine while maintaining the engine speed based on the NV line as in the hybrid vehicle described in Patent Document 1, the operating point of the engine is There is a possibility that the fuel efficiency of the engine is deteriorated by deviating from the engine efficiency optimum operation line. On the other hand, as in the hybrid vehicle described in Patent Document 2, if the operating point of the engine is maintained when correcting the torque command of the motor and suppressing the rattling noise of the gear mechanism, it is output from the engine. While driving performance can be ensured while maintaining power, maintaining the operating point of the engine may cause other noises such as engine noise.

  Therefore, the present invention suppresses the generation of noise in a hybrid vehicle including an internal combustion engine that can output power to one of the front wheels and the rear wheels and an electric motor that can output power to the other of the front wheels and the rear wheels. The main purpose is to improve the fuel consumption of the internal combustion engine and to ensure good running performance.

  The control device and control method for a hybrid vehicle according to the present invention employs the following means in order to achieve the main object.

  A control apparatus for a hybrid vehicle according to the present invention includes an internal combustion engine capable of outputting power to one of the front wheels and the rear wheel, an electric motor capable of outputting power to the other of the front wheels and the rear wheel, and an electric power exchangeable with the motor. In a control device for a hybrid vehicle including a power storage device, the noise generation region includes an operation point corresponding to a required power for the internal combustion engine on a predetermined operation line so as to improve fuel consumption. The internal combustion engine is controlled to operate at an operating point on the operating line on a lower load side than the generation region, and the output of the electric motor is increased.

  This control device for a hybrid vehicle has a lower load than the noise generation region when the operation point corresponding to the required power for the internal combustion engine on the operation line determined in advance to improve fuel efficiency is included in the noise generation region. The internal combustion engine is controlled to operate at an operating point on the operating line on the side, and the output of the electric motor is increased. In this way, when the operating point corresponding to the required power on the operating line is included in the noise generation region, the generation of noise is suppressed by operating the internal combustion engine at an operating point on the operating line other than the noise generating region. The fuel consumption of the internal combustion engine can be improved. At this time, by increasing the output of the electric motor, it is possible to compensate for the shortage of output caused by operating the internal combustion engine at an operating point on the lower load side than the operating point corresponding to the required power. Therefore, according to this control device, it is possible to improve the fuel consumption of the internal combustion engine while suppressing the generation of noise, and to ensure good running performance of the hybrid vehicle.

  Further, the control device outputs a shortage of the power output from the internal combustion engine with respect to the required power when an operating point corresponding to the required power on the operating line is included in the noise generation region. In addition, the motor may be controlled. As a result, the power originally required for the internal combustion engine when the hybrid vehicle is traveling can be output from both the internal combustion engine and the electric motor, and the traveling performance of the hybrid vehicle can be ensured satisfactorily.

  Further, when the shortage of the power output from the internal combustion engine with respect to the required power cannot be output from the electric motor, the operating point on the second operating line determined to avoid the noise generation region The internal combustion engine may be controlled to operate at This makes it possible to improve the fuel efficiency of the internal combustion engine while stabilizing the running state and protecting the electric motor. If the shortage cannot be output from the motor, the output of the motor is limited from the viewpoint of stabilizing the running state of the vehicle, or the output of the motor is limited from the viewpoint of protecting the motor. In some cases, etc.

  The hybrid vehicle further includes second and third electric motors, a first element connected to a rotation shaft of the second electric motor, a drive shaft connected to one of the front wheels and the rear wheels, and the third electric motor. You may further provide the planetary gear which has the 2nd element connected to the rotating shaft of an electric motor, and the 3rd element connected to the output shaft of the said internal combustion engine. According to such a configuration, when an operation point corresponding to the required power on the operation line is included in the noise generation region, the actual operation point of the internal combustion engine is set on the operation line on the lower load side than the noise generation region. It is possible to easily set the operating point.

  Further, the hybrid vehicle may further include a continuously variable transmission that transmits power from the internal combustion engine to a drive shaft connected to one of the front wheels and the rear wheels. Even with such a configuration, when the operating point corresponding to the required power on the operation line is included in the noise generation region, the actual operation point of the internal combustion engine is operated on the operation line on the lower load side than the noise generation region. It becomes possible to easily set a point.

  The method for controlling a hybrid vehicle according to the present invention includes an internal combustion engine capable of outputting power to one of the front wheels and the rear wheel, an electric motor capable of outputting power to the other of the front wheels and the rear wheel, and electric power exchangeable with the motor. In a control method of a hybrid vehicle including a power storage device, the noise generation region includes an operation point according to a required power for the internal combustion engine on a predetermined operation line so as to improve fuel consumption. The internal combustion engine is controlled to operate at an operating point on the operating line on a lower load side than the generation region, and the output of the electric motor is increased.

  According to this method, when an operation point corresponding to the required power on the operation line is included in the noise generation region, the internal combustion engine is operated at an operation point on the operation line other than the noise generation region, thereby generating noise. The fuel consumption of the internal combustion engine can be improved while suppressing. At this time, by increasing the output of the electric motor, it is possible to compensate for the shortage of output caused by operating the internal combustion engine at an operating point on the lower load side than the operating point corresponding to the required power. Therefore, by adopting this method, it is possible to improve the fuel efficiency of the internal combustion engine while suppressing the generation of noise, and to ensure good running performance of the hybrid vehicle.

1 is a schematic configuration diagram of a hybrid vehicle 20 that is an example of a hybrid vehicle according to the present invention. 4 is a flowchart illustrating an example of a drive control routine that is executed when the hybrid vehicle 20 travels in a state where the engine 22 is operated. 4 is a flowchart illustrating an example of a drive control routine that is executed when the hybrid vehicle 20 travels in a state where the engine 22 is operated. It is explanatory drawing which shows an example of the map for request | requirement torque setting. 4 is an explanatory diagram illustrating a fuel efficiency optimum operation line and a noise avoidance operation line of the engine 22. FIG. It is a schematic block diagram of the hybrid vehicle 200 which is another example of the hybrid vehicle by this invention.

  Next, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 20 which is an example of a hybrid vehicle according to the present invention. A hybrid vehicle 20 shown in the figure includes an engine (internal combustion engine) 22 that outputs power using a hydrocarbon fuel such as gasoline and light oil, a single-pinion planetary gear 30, and a motor MG1 that mainly operates as a generator. A motor MG2 that inputs / outputs power to / from the front wheel drive shaft 37 connected to the front wheels 35a and 35b via the differential gear 36 and a gear mechanism (not shown) to the rear wheels 35c and 35d. And a motor MG3 for inputting / outputting power to / from a rear wheel drive shaft 39 connected through a differential gear 38.

  Further, hybrid vehicle 20 includes an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 that controls engine 22, inverters 41, 42, and 43 for driving motors MG 1, MG 2, and MG 3, and inverter 41 , 42 and 43, a motor electronic control unit (hereinafter referred to as “motor ECU”) 40 for driving and controlling motors MG 1, MG 2 and MG 3 via inverters 41, 42 and 43, and battery 50 A battery electronic control unit (hereinafter referred to as “battery ECU”) 52 and a hybrid electronic control unit (hereinafter referred to as “hybrid ECU”) that controls the entire vehicle while communicating with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like. 70) No.

  The engine ECU 24 is configured as a microcomputer centered on a CPU (not shown). The engine ECU 24 receives signals from various sensors that are provided to the engine 22 and detect the operating state of the engine 22. The engine ECU 24 receives the intake air amount, fuel injection amount, ignition timing, and the like of the engine 22. A control signal or the like for controlling is output. Further, the engine ECU 24 communicates with the hybrid ECU 70 to control the engine 22 based on a signal from the hybrid ECU 70, a signal from the sensor, and the like, and outputs data related to the operating state of the engine 22 to the hybrid ECU 70 as necessary. .

  Planetary gear 30 is connected to a sun gear (first element) 31 connected to the rotor (rotating shaft) of motor MG1 and to the front wheel drive shaft 37 and to the rotor (rotating shaft) of motor MG2 via transmission 60. And a planetary carrier (third element) 34 that supports a plurality of pinion gears 33 and is connected to a crankshaft (output shaft) of the engine 22 via a damper (not shown). The transmission 60 can connect and release the rotor of the motor MG2 and the front wheel drive shaft 37, and can set the gear ratio between the rotor and the front wheel drive shaft 37 in a plurality of stages. It is controlled by the hybrid ECU 70 according to the traveling state of the hybrid vehicle 20 and the like.

  When the motor MG1 functions as a generator that generates power using at least part of the power from the engine 22, the planetary gear 30 transmits the power from the engine 22 transmitted to the planetary carrier 34 to the sun gear 31 and the ring gear 32. Distribute according to gear ratio. In addition, planetary gear 30 integrates the power from engine 22 transmitted to planetary carrier 34 and the power from motor MG1 transmitted to sun gear 31 when motor MG1 functions as an electric motor, and outputs it to ring gear 32. The power output to the ring gear 32 is finally output to the front wheels 35a and 35b via the front wheel drive shaft 37, the differential gear 36, and the like.

  Motors MG1, MG2 and MG3 are configured as well-known synchronous generator motors, and exchange electric power with battery 50 through inverters 41, 42 or 43, respectively. The power line connecting inverters 41, 42 and 43 and battery 50 is configured as a positive and negative bus shared by inverters 41 to 43, and is generated by at least one of motors MG1, MG2 and MG3. Power can be consumed by the remaining motor. Therefore, the battery 50 is charged / discharged according to the electric power generated or consumed by the motors MG1 to MG3, and is not charged / discharged if the electric power balance is balanced between the motors MG1 to MG3.

  The motor ECU 40 is configured as a microcomputer centering on a CPU (not shown). The motor ECU 40 includes signals from rotational position detection sensors 45, 46 and 47 that detect the rotational positions of the rotors of the motors MG1 to MG3, phase currents applied to the motors MG1 to MG3 detected by a current sensor (not shown), and the like. The motor ECU 40 outputs a switching control signal and the like to the inverters 41 to 43. Further, motor ECU 40 calculates the rotational speeds Nm1, Nm2, and Nm3 of the rotors of motors MG1, MG2, and MG3 based on the signals input from rotational position detection sensors 45-47. Further, the motor ECU 40 communicates with the hybrid ECU 70, controls the driving of the motors MG1 to MG3 based on signals from the hybrid ECU 70, and outputs data related to the states of the motors MG1 to MG3 to the hybrid ECU 70 as necessary.

  The battery 50 is, for example, a nickel hydride secondary battery or a lithium ion secondary battery having a rated output voltage of 200 to 300V. The battery ECU 52 that manages the battery 50 is also configured as a microcomputer centering on a CPU (not shown). The battery ECU 52 includes a terminal voltage Vb from a voltage sensor (not shown) installed between terminals of the battery 50, and a charge / discharge current Ib from a current sensor (not shown) installed in a power line connected to the output terminal of the battery 50. The battery temperature Tb from a temperature sensor (not shown) installed in the battery 50 is input. Further, the battery ECU 52 communicates with the hybrid ECU 70 and the engine ECU 24 and outputs data relating to the state of the battery 50 to the hybrid ECU 70 and the engine ECU 24 as necessary. Further, the battery ECU 52 calculates the remaining capacity SOC indicating the charging ratio of the battery 50 based on the integrated value of the charging / discharging current Ib, or the charge / discharge required power as the target charging / discharging power of the battery 50 based on the remaining capacity SOC. As Pb * (here, the discharge side is positive and the charge side is negative), or the allowable charge power that is the power allowed for charging the battery 50 based on the remaining capacity SOC and the battery temperature Tb The input limit Win and the output limit Wout as the allowable discharge power that is the power allowed for the discharge of the battery 50 are calculated.

  The hybrid ECU 70 is configured as a microcomputer centering on the CPU 72, and includes a ROM 74 for storing various programs, a RAM 76 for temporarily storing data, an input / output port and a communication port (not shown), and the like in addition to the CPU 72. As described above, the hybrid ECU 70 communicates with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like, and exchanges various signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like. Further, the hybrid ECU 70 includes a shift range SR from the shift range sensor 82 that detects an ignition signal from the ignition switch (start switch) 80, a shift range SR corresponding to the operation position (shift position) of the shift lever 81, an accelerator pedal. Accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the depression amount (accelerator operation amount) of 83, brake pedal stroke BS from the brake pedal stroke sensor 86 that detects the depression amount of the brake pedal 85, and from the vehicle speed sensor 87 The vehicle speed V or the like is input via the input port.

  In the hybrid vehicle 20 configured as described above, the required torque T * required for traveling of the hybrid vehicle 20 is calculated based on the accelerator opening Acc and the vehicle speed V, and the torque corresponding to the required torque T * is the front wheel. The engine 22 and the motors MG1 to MG3 are controlled so as to be output to at least one of the drive shaft 37 and the rear wheel drive shaft 39. In the control mode of the engine 22 and the motors MG1 to MG3, the engine 22 is controlled so that power corresponding to the required torque T * is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. Torque conversion operation mode for driving and controlling the motors MG1 to MG3 so that torque is converted by one or both of the motors MG2 and MG3 and output to at least one of the front wheel drive shaft 37 and the rear wheel drive shaft 39; The engine 22 is controlled so that the power corresponding to the sum of the torque T * and the power required for charging / discharging the battery 50 is output from the engine 22 and the power output from the engine 22 with charging / discharging of the battery 50 is controlled. All or part of it is connected to planetary gear 30, motor MG1, and motor. The motors MG1 to MG3 are driven and controlled so that torque based on the required torque T * is output to at least one of the front wheel drive shaft 37 and the rear wheel drive shaft 39 with torque conversion by one or both of the motors MG2 and MG3. The motors MG2 and MG3 so that a torque based on the required torque T * is output to at least one of the front wheel drive shaft 37 and the rear wheel drive shaft 39 when the operation of the engine 22 is stopped. A motor operation mode for driving one or both is included.

  Next, the operation of the hybrid vehicle 20 configured as described above will be described. FIGS. 2 and 3 are flowcharts showing an example of a drive control routine executed by the hybrid ECU 70 every predetermined time (for example, every several msec) when the hybrid vehicle 20 travels with the engine 22 operated. .

  At the start of the drive control routine of FIG. 2, the hybrid ECU 70 (CPU 72) determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 87, the rotational speeds Nm1 to Nm3 of the motors MG1 to MG3, the battery. Input of data necessary for control such as 50 charge / discharge required power Pb *, current transmission ratio γ of transmission 60, rear wheel torque distribution ratio Dr, upper limit torques Tm2lim and Tm3lim of motors MG2 and MG3, and distribution ratio change prohibition flag Fp Processing is executed (step S100). The rotational speeds Nm1 to Nm3 of the motors MG1 to MG3 are input from the motor ECU 40 through communication, and the charge / discharge request power Pb * of the battery 50 is input from the battery ECU 52 through communication. The current transmission gear ratio γ of the transmission 60 is a transmission gear ratio set by the transmission 60 when the process of step S100 is executed according to the vehicle speed V, the required torque T *, etc., for example, and is a storage area (not shown) of the hybrid ECU 70 Is stored.

  The rear wheel torque distribution ratio Dr is separately set by the hybrid ECU 70 within a range of, for example, a value of 0 to a value of 0.5 according to the traveling state of the hybrid vehicle 20 (vehicle speed V, required torque T *, steering angle, etc.). And is stored in a storage area (not shown) of the hybrid ECU 70. The upper limit torque Tm2lim is the maximum torque that is allowed to be output from the motor MG2 at that time. In step S100, the torque set by the motor ECU 40 according to the temperature of the motor MG2 and the rotational speed Nm2 is communicated. Entered. Similarly, the upper limit torque Tm3lim is the maximum torque that is allowed to be output from the motor MG3 at that time. In step S100, the upper limit torque Tm3lim is set by the motor ECU 40 according to the temperature of the motor MG3, the rotational speed Nm3, or the like. Is input by communication. The distribution ratio change prohibition flag Fp is set to a value of 0 when the change of the rear wheel torque distribution ratio Dr set as described above is allowed, and the change of the rear wheel torque distribution ratio Dr is not allowed. Is set to a value of 1. In the present embodiment, the distribution ratio change prohibition flag Fp is set by the hybrid ECU 70 in accordance with the traveling state (vehicle speed V, required torque T *, steering angle, etc.) of the hybrid vehicle 20, the road surface state, the state of the battery 50, and the like. It is what is done. The distribution ratio change prohibition flag Fp is, for example, when the vehicle speed V is included in a predetermined range, when the required torque T * is included in a predetermined range, when the hybrid vehicle 20 is turning, when traveling on a low μ road, and when the battery 50 Is set to 1 when the remaining capacity SOC of the battery 50 is less than a predetermined value, or when the output limit Wout of the battery 50 is less than a predetermined value.

  After the data input process in step S100, the hybrid ECU 70 derives and sets the required torque T * corresponding to the accelerator opening Acc and the vehicle speed V input in step S100 from the required torque setting map illustrated in FIG. Thus, the engine required power Pe * required for the engine 22 is set (step S110). The required engine power Pe * is obtained by subtracting the required charge / discharge power Pb * from the product of the required torque T * and the product of the vehicle speed V and the conversion factor k (the rotational speed of the front wheel drive shaft 37 and the rear wheel drive shaft 39). It is obtained by adding the loss Loss to the value. Next, the hybrid ECU 70 determines whether or not the set required engine power Pe * is larger than a predetermined value P1 and smaller than a predetermined value P2 (whether P1 <Pe * <P2). Is determined (step S120).

  If the engine required power Pe * is equal to or less than the value P1, or equal to or greater than the value P2, the hybrid ECU 70 sets the engine required power Pe set in step S110 from a fuel efficiency optimum operation line that is determined in advance so as to improve fuel efficiency. A target operating point of the engine 22 corresponding to *, that is, a target rotational speed Ne * and a target torque Te * are set (step S130). When engine required power Pe * is larger than value P1 and smaller than value P2, hybrid ECU 70 further determines whether or not distribution ratio change prohibition flag Fp input in step S100 is value 1. (Step S140). When the distribution ratio change prohibition flag Fp is 1 and the change of the rear wheel torque distribution ratio Dr is not permitted, the hybrid ECU 70 sets the engine required power Pe set in step S110 from a predetermined noise avoidance operation line. The target operating point of the engine 22 corresponding to *, that is, the target rotational speed Ne * and the target torque Te * are derived and set (step S150).

  FIG. 5 illustrates a fuel efficiency optimum operation line and a noise avoidance operation line. The optimum fuel consumption operation line indicated by a solid line in FIG. 3 is obtained by connecting operating points at which the engine 22 is operated most efficiently for each engine required power Pe * obtained through experiments and analyses. In addition, the noise avoidance operation line indicated by the alternate long and short dash line in FIG. 5 can avoid a noise generation region (see the shaded portion in FIG. 5) that generates noise such as a booming noise of the engine 22 among the operable regions of the engine 22. It is determined so that the fuel consumption of the engine 22 is as good as possible within the range. That is, in the example of FIG. 5, when the engine 22 operates at an operating point on the low rotation side (left side in the figure) or high torque side (upper side in the figure) with respect to the operating point on the noise avoidance operation line, This will increase the risk of occurrence.

  Then, the value P1 as the threshold used in step S120 is smaller than the minimum power among the powers defined by the operating points on the fuel efficiency optimal operation line included in the noise generation region and is close to the minimum power. It is determined as a value. Further, the value P2 as the threshold value used in step S120 is larger than the maximum power among the powers defined by the operating points on the fuel consumption optimal operation line included in the noise generation region, and is close to the maximum power. It is determined as a value. As a result, when it is determined in step S120 that the engine required power Pe * is equal to or less than the value P1, or equal to or greater than the value P2, the engine 22 at the target operating point set using the fuel efficiency optimal operation line. Even if the engine is operated, the possibility that the actual operating point of the engine 22 is included in the above-described noise generation region is extremely low, and the fuel efficiency of the engine 22 can be improved without generating a noise such as a booming noise. On the other hand, when it is determined in step S120 that the engine required power Pe * is larger than the value P1 and smaller than the value P2, the engine is operated at the target operating point set by using the fuel efficiency optimal operation line. When the engine 22 is operated, the possibility that the operating point of the engine 22 is included in the above-described noise generation region becomes extremely high. For this reason, an affirmative determination is made in step S120, and when the distribution ratio change prohibition flag Fp is 1 and the change of the rear wheel torque distribution ratio Dr is not permitted, a slight reduction in fuel consumption is caused. If so, the target operating point of the engine 22 is set using the noise avoiding operation line so that the generation of noise is suppressed (step S150).

  After setting the target operating point of the engine 22 in step S130 or S150, the hybrid ECU 70 determines the front wheel based on the rear wheel torque distribution ratio Dr input in step S100 and the required torque T * set in step S110. The front wheel required torque Tf * (= (1-Dr) · T *) to be output to 35a and 35b and the rear wheel required torque Tr * (= Dr · T *) to be output to the rear wheels 35c and 35d are set. (Step S160). Subsequently, the hybrid ECU 70 determines the target rotational speed Ne *, the rotational speed of the front wheel drive shaft 37 (= Nm2 / γ or k · V), and the gear ratio ρ of the planetary gear 30 (the number of teeth of the sun gear 31 / the number of teeth of the ring gear 32). Is calculated in accordance with the following equation (1), and the torque for the motor MG1 is calculated based on the target torque Te *, the target rotational speed Nm1 *, the current rotational speed Nm1, and the like of the engine 22. Command Tm1 * is set according to the following equation (2) (step S170). Expression (1) is a dynamic relational expression related to the rotating element of the planetary gear 30 and can be easily derived from a nomographic chart (not shown) showing a dynamic relation between the rotational speed and torque in the rotating element of the planetary gear 30. It is. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at a target rotation speed Nm1 * corresponding to the target rotation speed Ne * of the engine 22, and the second term on the right side in the expression (2). “K1” is a gain of the proportional term, and “k2” of the third term on the right side is a gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / (γ ・ ρ) (1)
Tm1 * =-ρ / (1 + ρ) ・ Te * + k1 ・ (Nm1 * -Nm1) + k2 ・ ∫ (Nm1 * -Nm1) dt (2)

  After setting the torque command Tm1 * for the motor MG1 in this way, the hybrid ECU 70 determines the front wheel required torque Tf * and the gear ratio Gf (= f (γ) between the rotor of the motor MG2 and the front wheels 35a and 35b (front wheel drive shaft). ), Based on the torque command Tm1 *, the gear ratio ρ of the planetary gear 30 and the current gear ratio γ of the transmission 60, a temporary torque command Tm2tmp, which is a temporary value of torque to be output from the motor MG2, is calculated according to the following equation (3). (Step S180). Further, hybrid ECU 70 sets the smaller of temporary torque command Tm2tmp and upper limit torque Tm2lim of motor MG2 input at step S100 as torque command Tm2 * for motor MG2 (step S190). Further, the hybrid ECU 70 temporarily calculates the torque to be output from the motor MG3 based on the rear wheel required torque Tr * and the gear ratio Gr between the rotor of the motor MG3 and the rear wheels 35c and 35d (rear wheel drive shaft). Is calculated according to the following equation (4) (step S200). Further, hybrid ECU 70 sets the smaller of temporary torque command Tm3tmp and upper limit torque Tm3lim of motor MG3 input at step S100 as torque command Tm3 * for motor MG3 (step S210).

Tm2tmp = (Tf * / Gf + Tm1 * / ρ) / γ (3)
Tm3tmp = Tr * / Gr (4)

  After setting the torque commands Tm1 *, Tm2 * and Tm3 * for the motors MG1 to MG3 as described above, the hybrid ECU 70 transmits the target rotational speed Ne * and the target torque Te * of the engine 22 to the engine ECU 24 and Torque commands Tm1 * to Tm3 * of MG1 to MG3 are transmitted to the motor ECU 40 (step S220), and this routine is temporarily terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * from the hybrid ECU 70 executes intake air amount control, fuel injection control, ignition timing control, and the like based on the target rotational speed Ne * and the target torque Te *. To do. Further, the motor ECU 40 that receives the torque commands Tm1 * to Tm3 * from the hybrid ECU 70 performs switching control of the switching elements of the inverters 41 to 43 based on the torque commands Tm1 * to Tm3 *.

  On the other hand, it is determined in step S120 that the engine required power Pe * is larger than the value P1 and smaller than the value P2, and in step S140, the distribution ratio change prohibition flag Fp is 0 and the rear wheel torque distribution ratio. When it is determined that the change of Dr is permitted, the hybrid ECU 70 determines the required engine power Pe * set in step S110, the above-described value P1, the rotational speed Nm3 of the motor MG3 input in step S100, and the above-described value. Based on the gear ratio Gr, the rear wheel required torque Tr * to be output to the rear wheels 35c and 35d is set according to the following equation (5), and the rear wheel required torque Tr set from the required torque T * according to the following equation (6): By subtracting *, the front wheel required torque Tf * to be output to the front wheels 35a and 35b is set (step S230). Here, Expression (5) is to convert the shortage of the value P1 (power output from the engine 22) with respect to the original engine required power Pe * into torque to the rear wheels 35c and 35d.

Tr * = (Pe * -P1) / (Nm3 / Gr) (5)
Tf * = T * -Tr * (6)

  Subsequently, the hybrid ECU 70 determines whether or not the rear wheel required torque Tr * set in step S230 is equal to or less than the product of the upper limit torque Tm3lim and the gear ratio Gr of the motor MG3 input in step S100, that is, the upper limit torque Tm3lim. It is determined whether or not the rear wheel required torque Tr * can be output from the motor MG3 to the rear wheels 35c and 35d within the range of (rated torque) (step S240). When the rear wheel required torque Tr * is equal to or less than the product of the upper limit torque Tm3lim and the gear ratio Gr, the hybrid ECU 70 sets the rear wheel required torque Tr * set in step S230 to the required torque T * set in step S110. The predicted rear wheel torque distribution ratio Dpre is calculated by dividing (step S250). Further, the hybrid ECU 70 determines whether or not the calculated predicted rear wheel torque distribution ratio Dpre exceeds a predetermined upper limit rear wheel torque distribution ratio Dlim (step S260). In the present embodiment, the upper limit rear wheel torque distribution ratio Dlim as a threshold used in step S260 is the maximum value (for example, 0.5) of the rear wheel torque distribution ratio Dr set according to the traveling state of the hybrid vehicle 20. ).

  When the predicted rear wheel torque distribution ratio Dpre is equal to or less than the upper limit rear wheel torque distribution ratio Dlim, the hybrid ECU 70 sets the target operating point of the engine 22 to the operating point corresponding to the value P1 on the fuel efficiency optimal operating line (the equal power of the value P1). (Intersection of line and fuel efficiency optimal operation line) (step S270). In other words, if engine required power Pe * is larger than value P1 or smaller than value P2, change of rear wheel torque distribution ratio Dr is permitted, and output of motor MG3 is not limited by upper limit torque Tm3lim, step S270. The target rotational speed Ne * is set to the value Ne1, and the target torque Te * is set to the value Te1 (= P1 / Ne1). Then, the hybrid ECU 70 executes the processes of steps S170 to S220 described above, and once ends this routine.

  On the other hand, when it is determined in step S260 that the predicted rear wheel torque distribution ratio Dpre exceeds the upper limit rear wheel torque distribution ratio Dlim, the hybrid ECU 70 outputs excessive torque to the rear wheels 35c and 35d. Based on the upper limit rear wheel torque distribution ratio Dlim and the required torque T * set in step S110 in order to prevent the running state from becoming unstable, the front wheel required torque Tf * ( = (1-Dlim) · T *) and the rear wheel required torque Tr * (= Dlim · T *) to be output to the rear wheels 35c and 35d are reset (step S280). Further, the hybrid ECU 70 requests the engine request based on the engine required power Pe * set in step S110, the reset rear wheel required torque Tr *, the rotation speed Nm3 of the motor MG3 input in step S100, and the gear ratio Gr. The power Pe * is reset according to the following equation (7) (step S290), and the target rotational speed Ne * and the target torque Te * of the engine 22 corresponding to the engine required power Pe * reset from the noise avoidance operation line described above are set. Derivation and setting (step S300). Thereafter, the hybrid ECU 70 executes the processes of steps S170 to S220 described above, and once ends this routine.

  Pe * = Pe * -Tr * ・ Nm3 / Gr (7)

  Further, when it is determined in step S240 that the rear wheel required torque Tr * exceeds the product of the upper limit torque Tm3lim and the gear ratio Gr, the hybrid ECU 70 increases the output torque of the motor MG3 from the viewpoint of protecting the motor MG3. The rear wheel required torque Tr * is reset to the product of the upper limit torque Tm3lim and the gear ratio Gr to limit the torque within the range of the torque Tm3lim, and the rear wheel required torque set from the required torque T * according to the above equation (6). The front wheel required torque Tf * to be output to the front wheels 35a and 35b is reset by reducing Tr * (step S310). Thereafter, the hybrid ECU 70 executes the processes of steps S290 and S300 and S170 to S220 described above, and once ends this routine.

  When the drive control routine as described above is executed, the operating point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimum operation line determined in advance so as to improve fuel efficiency is a noise generation region (FIG. 5). Included in the two-dot chain line), the output of the motor MG3 should be limited from the viewpoint of stabilizing the running state and protecting the motor MG3 (and also the battery 50) (the motor MG3 may output the shortage). The target operating point of the engine 22 is set to the operating point (Ne1, Te1) on the fuel efficiency optimal operating line on the lower load side (lower power side) than the noise generation region (step S270). Therefore, the engine 22 is controlled by the engine ECU 24 so as to operate at the operating point (Ne1, Te1) on the fuel efficiency optimal operation line on the lower load side (lower power side) than the noise generation region. In addition, as the target operating point of the engine 22 is set in this way, the torque command Tm3 of the motor MG3 is output so as to output a shortage of the power (value P1) output from the engine 22 with respect to the engine required power Pe *. * Is set (steps S210 and S230). Thus, when the motor MG3 is controlled by the motor ECU 40 in accordance with the torque command Tm3 *, when the required torque T * increases according to the accelerator opening Acc, the output (power) of the motor MG3 is basically the engine. The output (power) of 22 is increased by the amount that can be suppressed. Furthermore, even when the operating point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimal operation line is included in the noise generation region, the running state is stabilized and the motor MG3 (and the battery 50) is protected. When the output of the motor MG3 is to be limited from the viewpoint, the target operating point of the engine 22 is set to an operating point on the noise avoiding operation line determined so as to avoid the noise generation region (step S300). Torque command Tm3 * of motor MG3 is set so as to output torque within an allowable range (step S210, S280 or S310).

  As described above, in the hybrid vehicle 20, when the operating point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimal operation line determined in advance to improve fuel efficiency is included in the noise generation region, The engine 22 is controlled so as to operate at the operating point (Ne1, Te1) on the fuel efficiency optimal operation line on the lower load (low power) side than the generation region, and the output (power) of the engine 22 is suppressed. The output of motor MG3 is increased. As described above, when the operating point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimal operation line is included in the noise generation region, the engine 22 is operated at an operating point on the fuel efficiency optimal operation line other than the noise generation region. By doing so, it is possible to improve the fuel consumption of the engine 22 while suppressing the generation of noise. At this time, by increasing the output of the motor MG3, the shortage of output caused by operating the engine 22 at an operating point on the lower load (low power) side than the operating point corresponding to the engine required power Pe * is compensated. be able to. Therefore, it is possible to improve the fuel efficiency of the engine 22 while suppressing the generation of noise, and to ensure good running performance of the hybrid vehicle 20.

  Further, in the hybrid vehicle 20, when the operating point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimal operation line is included in the noise generation region, the engine request of the power (value P1) output from the engine 22 The motor MG3 is controlled so as to output the shortage relative to the power Pe *. As a result, the power (Pe *) originally required for the engine 22 when the hybrid vehicle 20 travels can be output from both the engine 22 and the motor MG3, and the traveling performance of the hybrid vehicle 20 can be ensured satisfactorily. Become.

  Further, in the hybrid vehicle 20, the shortage of the power (value P1) output from the engine 22 with respect to the engine required power Pe * in order to stabilize the traveling state and protect the motor MG3 can be output from the motor MG3. If not, the engine 22 is controlled so as to operate at an operating point on the noise avoiding operation line determined to avoid the noise generation region. As a result, the fuel consumption of the engine 22 can be improved while stabilizing the running state and protecting the motor MG3.

  The hybrid vehicle 20 includes motors MG1 and MG2, a sun gear 31 connected to the rotor of the motor MG1, a front wheel drive shaft 37 connected to the front wheels 35a and 35b, and a ring gear 32 connected to the rotor of the motor MG2. And a planetary gear 30 having a planetary carrier 34 connected to the crankshaft of the engine 22. Thereby, in the hybrid vehicle 20, when the operating point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimal operating line is included in the noise generating region, the actual operating point of the engine 22 is set to be higher than the noise generating region. It is possible to easily set the operating point on the fuel efficiency optimum operating line on the low load side. However, it goes without saying that the rear wheel drive shaft 39 and the motor MG2 may be connected to the ring gear 32 of the planetary gear 30, and the motor MG3 may be connected to the front wheel drive shaft 37.

  Furthermore, the hybrid vehicle to which the present invention is applied may include a continuously variable transmission (CVT) 65 like a hybrid vehicle 200 according to the modification shown in FIG. The hybrid vehicle 200 according to the modification shown in FIG. 6 is connected to the crankshaft of the engine 22 and can exchange electric power with the battery 50 via the inverter 49f, the rotor (rotary shaft) of the motor MGf, and the front wheels. A mechanical (for example, belt type or toroidal) continuously variable transmission 65 connected to the front wheel drive shaft 37 coupled to 35a, 35b, a battery connected to the rear wheel drive shaft 39 and via an inverter 49r. 50 and a motor MGr capable of exchanging electric power. Also in the hybrid vehicle 200 configured as described above, when the operation point of the engine 22 corresponding to the engine required power Pe * on the fuel efficiency optimal operation line is included in the noise generation region, the actual operation point of the engine 22 is determined as noise. It is possible to easily set the operating point on the fuel efficiency optimal operating line on the lower load side than the generation region. However, in hybrid vehicle 200, motor MGf and inverter 49f may be omitted, and engine 22 (and motor MGf) is connected to rear wheel drive shaft 39 via continuously variable transmission 65, and motor MGr is connected to front wheel drive shaft. 37 may be connected.

  If the motor MG3 cannot output a shortage of the power (value P1) output from the engine 22 with respect to the original engine required power Pe *, the motor MG3 outputs a torque within an allowable range. Instead of setting the torque command Tm3 * (steps S210, S280, or S310), the torque command Tm3 * of the motor MG3 is set to the value 0, and the engine required power Pe * and the noise avoiding operation line set in step S110 are set. May be used to set the target operating point of the engine 22. Further, during the processing of steps S170 to S220 in FIG. 2, the torque command Tm1 for the motors MG1 to MG3 so that the electric power input / output by the motors MG1 to MG3 is included in the range of the input limit Win and the output limit Wout of the battery 50. * To Tm3 * may be set. In this case, the output (output torque) of the motor MG3 is limited by the input limit Win and the output limit Wout of the battery 50, and the shortage of the power (value P1) output from the engine 22 with respect to the original engine required power Pe * is calculated. If it is not possible to output from MG3, set torque command Tm3 * of motor MG3 to output torque within an allowable range, or set torque command Tm3 * to a value of 0 and a noise avoidance operation line The engine 22 may be controlled to operate at the upper operating point. Further, in the drive control routine of FIG. 2, the engine required power Pe * set in step S110 is within a range from a predetermined value Pref to a value P2 that is larger than the value P1 and smaller than the value P2 (Pref ≦ Pe * < When the input / output of the motor MG3 is not restricted and the input / output of the motor MG3 is not limited, the engine 22 is controlled so as to operate at the operating point (Ne2, Pe2) corresponding to the value P2 on the optimal fuel consumption operating line (operating line) (target) The motor MG3 may be controlled (the torque command Tm3 is set) so as to output the difference between the power (value P2) output from the engine 22 and the original engine required power Pe *. . In addition, the hybrid vehicle 20 may employ a simple reduction gear mechanism instead of the transmission 60.

  Here, the correspondence between the main elements of the above embodiment and the main elements of the invention described in the column of means for solving the problems will be described. That is, in the above embodiment, the engine 22 as an internal combustion engine capable of outputting power to one of the front wheels 35a, 35b and the rear wheels 35c, 35d and power to the other of the front wheels 35a, 35b and the rear wheels 35c, 35d can be output. A hybrid vehicle 20 or 200 including a motor MG3 or MGr as a simple electric motor and a battery 50 as a power storage device capable of exchanging electric power with the motor MG3 or MGr corresponds to a “hybrid vehicle”. A combination of the hybrid ECU 70 that executes the drive control routine, the engine ECU 24, and the motor ECU 40 corresponds to a “control device”. Further, the motor MG1 corresponds to a “second electric motor”, the motor MG2 corresponds to a “third electric motor”, the planetary gear 30 corresponds to a “planetary gear”, and the continuously variable transmission 65 corresponds to a “continuously variable transmission”. It corresponds to. However, the correspondence between the main elements of the above embodiment and the main elements of the invention described in the column of means for solving the problem is described in the column of means for solving the problem by the embodiment. Since it is an example for concretely explaining the form for carrying out the invention, the element of the invention indicated in the column of the means for solving a subject is not limited. That is, the above embodiment is merely a specific example of the invention described in the section for solving the problem, and the interpretation of the invention described in the section for solving the problem is not limited to that section. This should be done based on the description.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention. .

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

  20,200 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 30 planetary gear, 31 sun gear, 32 ring gear, 33 pinion gear, 34 planetary carrier, 35a, 35b front wheel, 35c, 35d rear wheel, 36, 38 Differential gear, 37 Front wheel drive shaft, 39 Rear wheel drive shaft, 40 Motor electronic control unit (motor ECU), 41, 42, 43, 49f, 49r Inverter, 45, 46, 47 Rotation position detection sensor, 50 Battery, 52 Battery electronic control unit (battery ECU), 60 transmission, 65 continuously variable transmission, 70 hybrid electronic control unit (hybrid ECU), 72 CPU, 74 ROM, 76 RAM, 81 shift lever, 82 shift Range sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 87 vehicle speed sensor, MG1, MG2, MG3, MGf, MGr motor.

Claims (6)

Control of a hybrid vehicle comprising an internal combustion engine capable of outputting power to one of the front wheels and rear wheels, an electric motor capable of outputting power to the other of the front wheels and rear wheels, and a power storage device capable of exchanging electric power with the motor In the device
When an operation point corresponding to the required power for the internal combustion engine on the predetermined operation line so as to improve fuel consumption is included in the noise generation region, the operation line on the lower load side than the noise generation region A control apparatus for a hybrid vehicle, wherein the internal combustion engine is controlled to operate at an operating point, and the output of the electric motor is increased. In the hybrid vehicle control device according to claim 1,
Controlling the electric motor to output a shortage of the power output from the internal combustion engine with respect to the required power when an operating point corresponding to the required power on the operating line is included in the noise generation region. A hybrid vehicle control device. In the hybrid vehicle control device according to claim 2,
When the shortage of the power output from the internal combustion engine with respect to the required power cannot be output from the electric motor, the motor operates at an operating point on a second operating line determined to avoid the noise generation region. A control device for a hybrid vehicle, characterized by controlling the internal combustion engine. In the control apparatus of the hybrid vehicle as described in any one of Claim 1 to 3,
The hybrid vehicle includes second and third electric motors, a first element connected to a rotation shaft of the second electric motor, a drive shaft connected to one of the front wheels and the rear wheels, and the third electric motor. A hybrid vehicle, further comprising a planetary gear having a second element connected to a rotating shaft and a third element connected to an output shaft of the internal combustion engine. In the control apparatus of the hybrid vehicle as described in any one of Claim 1 to 3,
The hybrid vehicle further includes a continuously variable transmission that transmits power from the internal combustion engine to a drive shaft connected to one of the front wheels and the rear wheels. Control of a hybrid vehicle comprising an internal combustion engine capable of outputting power to one of the front wheels and rear wheels, an electric motor capable of outputting power to the other of the front wheels and rear wheels, and a power storage device capable of exchanging electric power with the motor In the method
When an operation point corresponding to the required power for the internal combustion engine on the predetermined operation line so as to improve fuel consumption is included in the noise generation region, the operation line on the lower load side than the noise generation region A control method for a hybrid vehicle, wherein the internal combustion engine is controlled to operate at an operating point and the output of the electric motor is increased.

Images