JP2007296933A - Vehicle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To regenerate the kinetic energy of a vehicle as power as much as possible, and to maintain the stability of a vehicle. <P>SOLUTION: In applying the brake in the middle of traveling at a relatively high speed, when an engine 22 is operated, the operation is stopped, and a crankshaft 26 is fixed so as not to be rotatable by a clutch C1 mounted on the crankshaft 26, and the regeneration of motors MG1 and MG2 is controlled based on the load distribution of front and back wheels during traveling, and a hydraulic brake is operated. Thus, it is possible to generate a large regeneration power even in not only the motor MG2 but also the motor MG1 in such a status that the stability of the vehicle is secured, and to regenerate the kinetic energy of the vehicle as power as much as possible. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

Conventionally, as this type of vehicle, a planetary gear connected to the front wheel side via a ring gear, an engine having an output shaft connected to the planetary gear carrier, a generator having a rotating shaft connected to the sun gear of the planetary gear, A vehicle including an electric motor coupled to the rear wheel side has been proposed (see, for example, Patent Document 1). In this vehicle, the power from the engine and the power from the generator are distributed and integrated by the planetary gear and output to the front wheel side, and the power from the electric motor is output to the rear wheel side to travel.
JP-A-2005-306214

  In the above-described vehicle, in order to improve the energy efficiency of the vehicle, it may be possible to control the electric motor and the generator so that more of the kinetic energy of the vehicle is regenerated as electric power during braking. Regeneration as energy power requires the reaction force of the carrier due to the characteristics of the planetary gear, so that large power cannot be regenerated. In addition, when the braking force acting on the front and rear wheels becomes unbalanced, the stability of the vehicle during braking may be hindered.

  One object of the vehicle and the control method thereof according to the present invention is to regenerate more of the kinetic energy of the vehicle as electric power. Another object of the vehicle and its control method of the present invention is to maintain the stability of the vehicle.

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

The vehicle of the present invention
An internal combustion engine;
A plurality of rotating elements including a first rotating element connected to an output shaft of the internal combustion engine and a second rotating element connected to a first axle; Electric power input / output means capable of inputting / outputting power to / from the first rotating element and the second rotating element;
Fixing means capable of fixing the first rotating element in a non-rotatable manner;
An electric motor capable of inputting and outputting power to a second axle different from the first axle;
A power storage means capable of exchanging power with the electric power drive input / output means and the electric motor;
Required driving force setting means for setting required driving force required for traveling;
When the set required driving force is a braking force and a predetermined condition is satisfied, the fixing means is controlled so that the first rotating element is unable to rotate, and the power power input / output means and the electric motor Control means for controlling the power drive input / output means and the motor so that regenerative power is generated;
It is a summary to provide.

  In the vehicle of the present invention, when the braking force is required and the predetermined condition is satisfied, the first rotating element connected to the output shaft of the internal combustion engine among the electric power power input / output means is fixed so as not to rotate. Power and power input / output so that regenerative power is generated from power power input / output means for controlling power and input / output power to and from the second rotating element connected to the first axle and motor for inputting and outputting power to the second axle. Control means and motor. Thereby, not only the electric motor but also the electric power drive input / output means can generate a large regenerative electric power, and more of the kinetic energy of the vehicle can be regenerated as electric power. Here, the “predetermined condition” includes a condition in which the vehicle speed is equal to or higher than a threshold, a condition in which the required driving force as a braking force is equal to or higher than the threshold, and the like.

  In such a vehicle of the present invention, the first axle braking force to be output to the first axle and the second axle to be output based on the vehicle weight distribution with respect to the first axle and the second axle. Axle braking force setting means for setting the second axle braking force, and a first target braking torque to be output from the electric power input / output means based on the set first axle braking force and the set value. Target braking torque setting means for setting a second target braking torque to be output from the electric motor based on the second axle braking force, and the control means has the set first target braking torque as the electric power. The power input / output means and the electric motor may be controlled so that the set second target braking torque is output from the electric motor and output from the electric power input / output means. . If it carries out like this, the braking force based on a vehicle weight distribution can be output to a 1st axle shaft and a 2nd axle shaft, and, thereby, the stability of a vehicle can be ensured.

  Further, in the vehicle of the present invention, the first maximum braking force that can be output to the first axle and the second axle can be output based on the vehicle weight distribution with respect to the first axle and the second axle. A maximum braking force setting means for setting a second maximum braking force, a first target braking torque to be output from the electric power drive input / output means within a range of the set first maximum braking force, and Target braking torque setting means for setting a second target braking torque to be output from the electric motor within a range of the set second maximum braking force, and the control means has the set first target braking torque. Is outputted from the electric power drive input / output means and is a means for controlling the electric power drive input / output means and the electric motor so that the set second target braking torque is outputted from the electric motor. it canIn this way, since the electric power drive input / output means is driven within the range of the first maximum braking force and the electric motor is driven within the range of the second maximum braking force, more kinetic energy of the vehicle can be regenerated as electric power. The stability of the vehicle can be ensured.

  The vehicle according to the present invention further includes a braking force applying unit capable of applying a braking force to the vehicle, and the control unit controls the braking force applying unit so that a braking force based on the set required driving force acts. It can also be a means to do. In this way, the braking force based on the required driving force can be applied to the vehicle even when the braking force by the power power input / output means and the electric motor is insufficient.

  Alternatively, the vehicle according to the present invention includes connection release means for connecting and releasing the connection between the output shaft of the internal combustion engine and the first rotating element, and the control means includes the output shaft of the internal combustion engine and the first shaft. It may be a means for controlling the connection release means so that the connection with the rotating element is released. If it carries out like this, the 1st rotation element of an electric power motive power input / output means can be made non-rotatable without the operation stop of an internal combustion engine.

  In addition, in the vehicle of the present invention, the power / power input / output means includes a plurality of rotating elements including the first rotating element, the second rotating element, and a third rotating element connected to a rotating shaft. The remaining rotating elements rotate based on the rotation of any two rotating elements of the plurality of rotating elements, and the first rotating element and the second rotating element have a balance of power input to and output from the plurality of rotating elements. And a plurality of rotating element power input / output means for inputting / outputting power to / from the third rotating element, and a generator capable of inputting / outputting power to / from the rotating shaft. The power drive input / output means is a counter-rotor motor that includes a first rotor as the first rotating element and a second rotor as the second rotating element, and rotates relatively by electromagnetic action. It can also be.

The vehicle control method of the present invention includes:
A plurality of rotating elements including an internal combustion engine, a first rotating element connected to the output shaft of the internal combustion engine, and a second rotating element connected to the first axle, and with input and output of electric power and power Power power input / output means capable of inputting / outputting power to / from at least the first rotating element and the second rotating element, fixing means capable of fixing the first rotating element so as not to rotate, and the first axle. A vehicle control method comprising: an electric motor capable of inputting / outputting power to / from a different second axle; and an electric power input / output means and an electric storage means capable of exchanging electric power with the electric motor,
When a braking force is required and a predetermined condition is established, the fixing means is controlled so that the first rotating element cannot rotate, and regenerative electric power is generated from the electric power input / output means and the electric motor. Controlling the power drive input / output means and the motor;
It is characterized by that.

  In the vehicle control method of the present invention, when a braking force is required and a predetermined condition is satisfied, the first rotating element connected to the output shaft of the internal combustion engine among the power power input / output means becomes non-rotatable. Electric power is generated so that regenerative power is generated from an electric power input / output means for controlling the fixing means and inputting / outputting power to / from the second rotating element connected to the first axle and an electric motor inputting / outputting power to / from the second axle. The power input / output means and the electric motor are controlled. Thereby, not only the electric motor but also the electric power drive input / output means can generate a large regenerative electric power, and more of the kinetic energy of the vehicle can be regenerated as electric power. Here, the “predetermined condition” includes a condition in which the vehicle speed is equal to or higher than a threshold, a condition in which the required driving force as a braking force is equal to or higher than the threshold, and the like.

  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 is connected to an engine 22 and a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and a differential gear 62 and a gear mechanism 60 are connected to front wheels 63a and 63b. Via a three-shaft type power distribution and integration mechanism 30 connected via the power distribution motor 30, a motor MG1 capable of generating electricity connected to the power distribution and integration mechanism 30, and the rear wheels 68a and 68b via a differential gear 67 and a gear mechanism 65. A motor MG2 capable of generating electricity and a hybrid electronic control unit 70 for controlling the entire vehicle are provided.

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 front wheels 63a and 63b are connected to the ring gear 32 via the gear mechanism 60 and the differential gear 62, respectively. Yes. The carrier 34 of the power distribution and integration mechanism 30 can be non-rotatably fixed to a case (not shown) by the clutch C1, and the sun gear 31 can be non-rotatably fixed to the case (not shown) by the clutch C2. In a state where both the clutch C1 and the clutch C2 are turned off, the power distribution and integration mechanism 30 functions as a normal operating gear. When the motor MG1 functions as a generator, the power from the engine 22 input from the carrier 34 is transmitted to the sun gear. It distributes to the 31 side and the ring gear 32 side according to the gear ratio, and when the motor MG1 functions as an electric motor, the power from the engine 22 input from the carrier 34 and the power from the motor MG1 input from the sun gear 31 are integrated. To the ring gear 32 side. The power output to the ring gear 32 is output to the front wheels 63a and 63b via the gear mechanism 60 and the differential gear 62. In a state where the clutch C1 is turned on and the clutch C2 is turned off, the power distribution and integration mechanism 30 functions as a speed reducer with respect to the rotating shaft of the motor MG1, and amplifies the torque from the motor MG1 to a front wheel 63a, Output to the 63b side. When the clutch C1 is turned off and the clutch C2 is turned on, the power distribution and integration mechanism 30 functions as a speed increaser for the crankshaft 26 of the engine 22 and reduces the torque from the engine 22 to reduce the front wheel. Output to the 63a, 63b side. The state in which both the clutch C1 and the clutch C2 are turned on is not normally used because all the rotating elements of the power distribution and integration mechanism 30 cannot be rotated.

  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 the 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 from the temperature sensor (not shown) 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 brake actuator 69 has a braking torque corresponding to the share of the brake in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder (not shown) generated in response to the depression of the brake pedal 85 and the vehicle speed V. Regardless of adjusting the hydraulic pressure of the brake wheel cylinders 64a and 64b for the front wheels and the brake wheel cylinders 66a and 66b for the rear wheels so as to act on the 63b and the rear wheels 68a and 68b, The hydraulic pressure of the brake wheel cylinders 64a, 64b, 66a, 66b can be adjusted so that the braking torque acts on 63b and the rear wheels 68a, 68b. Hereinafter, a case where a braking force is applied to the front wheels 63a and 63b and the rear wheels 68a and 68b by the operation of the brake actuator 69 is referred to as a hydraulic brake. The brake actuator 69 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 61. The brake ECU 61 inputs signals such as a wheel speed from a wheel speed sensor (not shown) attached to the front wheels 63a and 63b and the rear wheels 68a and 68b and a steering angle from a steering angle sensor (not shown) through a signal line (not shown). The anti-lock brake system function (ABS) that prevents any of the front wheels 63a, 63b and the rear wheels 68a, 68b from slipping due to the lock when the driver depresses the brake pedal 85, or the driver depresses the accelerator pedal 83. Traction control (TRC) that prevents any of the front wheels 63a and 63b and the rear wheels 68a and 68b from slipping when the vehicle is stepped on, and posture maintenance control (VSC) that maintains the posture when the vehicle is turning. ). The brake ECU 61 is in communication with the hybrid electronic control unit 70, and controls the drive of the brake actuator 69 by a control signal from the hybrid electronic control unit 70, and the data regarding the state of the brake actuator 69 is used for the hybrid as necessary. Output to the electronic control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. From the accelerator pedal position Acc, the brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the G sensor 89 that detects the longitudinal acceleration of the vehicle. The acceleration α is input through the input port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, and the brake ECU 61 via the communication port, and the engine ECU 24, the motor ECU 40, the battery ECU 52, the brake ECU 61, and various control signals. And exchanging data.

  The hybrid vehicle 20 of the embodiment configured in this way is a request to be output to the front wheels 63a and 63b and the rear wheels 68a and 68b based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Torque is calculated, and the engine 22, the motor MG1, and the motor MG2 are controlled so that the required power corresponding to the required torque is output to the front wheels 63a and 63b and the rear wheels 68a and 68b. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22 while the clutch C1 and the clutch C2 are both off. Torque conversion for driving and controlling the motor MG1 and the motor MG2 so that all of the output power is torque-converted by the power distribution and integration mechanism 30, the motor MG1 and the motor MG2 and output to the front wheels 63a and 63b and the rear wheels 68a and 68b. The engine 22 is operated and controlled so that the power corresponding to the sum of the operation mode and the required power and the power required for charging and discharging the battery 50 is output from the engine 22 and is output from the engine 22 with charging and discharging of the battery 50. All or part of the power to be Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the required power is output to the front wheels 63a and 63b and the rear wheels 68a and 68b with torque conversion by the MG1 and the motor MG2, and the operation of the engine 22 is stopped. There is a motor operation mode in which operation control is performed so that power corresponding to the required power from the motor MG2 is output to the front wheels 63a and 63b and the rear wheels 68a and 68b. In addition, as described above, the operation control of the engine 22, the motor MG1, and the motor MG2 is performed by fixing the motor that travels with the power from the engine 22 and the power from the motor MG2 with the clutch C1 turned off and the clutch C2 turned on. There are an operation mode and an engine fixed operation mode in which the clutch C1 is turned on and the clutch C2 is turned off to travel by the power from the motor MG1 and the power from the motor MG2.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when the brake pedal 85 is depressed while traveling at a relatively high vehicle speed will be described. FIG. 2 is a flowchart showing an example of a braking time control routine executed by the hybrid electronic control unit 70. In this routine, when the vehicle speed V is a threshold value (for example, 50 km / h or more) and the brake pedal 85 is depressed relatively large (for example, the brake pedal position BP is 25% or more), every predetermined time (for example, every several msec) Repeatedly.

  When the braking control routine is executed, the CPU 72 of the hybrid electronic control unit 70 firstly, the brake pedal position BP from the brake pedal position sensor 86, the vehicle speed V from the vehicle speed sensor 88, the acceleration α from the G sensor 89, A process of inputting data necessary for control such as the rotational speeds Nm1, Nm2 of the motors MG1, MG2 is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do.

  When the data is input in this way, the required braking torque T * required for the axle is set based on the input brake pedal position BP and the vehicle speed V (step S110). Here, in the embodiment, the required braking torque T * is stored in the ROM 74 as a required braking torque setting map by previously determining the relationship among the brake pedal position BP, the vehicle speed V, and the required braking torque T *. When the position BP and the vehicle speed V are given, the corresponding required braking torque T * is derived from the map. An example of the required braking torque setting map is shown in FIG.

  Subsequently, it is checked whether or not the engine 22 is in operation (step S120). When the engine 22 is in operation, fuel injection is stopped so as to stop the operation of the engine 22 (step S130). Here, whether or not the engine 22 is in operation can be determined from a signal obtained from the engine ECU 24 indicating the operating state of the engine 22, the rotational speed of the engine 22, and the like. The process of stopping the operation of the engine 22 in step S130 is a process of maintaining the operation stop state when the engine 22 is stopped.

  Next, the clutch C1 is turned on and the clutch C2 is turned off (step S140). This process is a process of turning off the clutch C1 from off when the clutch C1 and the clutch C2 are both turned off and running in the torque conversion operation mode, the charge / discharge operation mode, and the motor operation mode, and the clutch C1 is turned off. At the same time, when the vehicle is traveling in the motor fixed operation mode with the clutch C2 turned on, the clutch C2 is turned off and then the clutch C1 is turned on. The clutch C1 is turned on and the clutch C2 is turned off to run in the engine fixed operation mode. When it is, it is a process of holding the state. FIG. 4 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 with the clutch C1 turned on and the clutch C2 turned off. 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 of the engine 22, and the R-axis indicates the rotation speed of the ring gear 32. Indicates.

  Thus, when the clutch C1 is turned on and the clutch C2 is turned off, the front wheel relative to the wheel base length L, which is the length between the axles of the front and rear wheels, is calculated on the vehicle weight Mg calculated as the product of the vehicle mass M and the gravitational acceleration g. The stationary rear wheel load Mr (= Mg · Lf / L), which is the load acting on the rear wheels 68a and 68b when stationary by multiplying the ratio of the horizontal length Lf from the axles 63a and 63b to the center of gravity of the vehicle And a stationary front wheel load Mf (= Mg−Mr), which is a load acting on the front wheels 63a and 63b when stationary, is calculated by subtracting the stationary rear wheel load Mr from the vehicle weight Mg (step S150). Here, the vehicle mass M, the gravitational acceleration g, the wheel base length L, and the length Lf are those previously stored in the ROM 74, but the vehicle mass M includes the weight of the occupant and the load. Alternatively, the vehicle weight Mg as the total weight may be obtained from a value detected by a sensor capable of detecting.

  Next, the calculated center of gravity of the rear wheel load Mr at rest, the front wheel load Mf at rest, the acceleration α, the mass M of the vehicle, the height of the axle of the front and rear wheels and the height of the center of gravity position of the vehicle. Based on the high H, a rear wheel drag Nr during traveling, which is a drag from the road surface acting on the rear wheels 68a and 68b during traveling, is calculated according to the following equation (1), and the front wheels 63a, A front wheel drag Nf during traveling which is a drag from the road surface acting on 63b is calculated (step S160). Here, the center-of-gravity height H is stored in the ROM 74 in advance. Since the time of braking of the vehicle is considered, the acceleration α is a negative value, and the running rear wheel drag Nr is smaller than the stationary rear wheel load Mr.

Nr = Mr ＋ α ・ M ・ H / L (1)
Nf = Mf−α ・ M ・ H / L (2)

  Then, a rear wheel load distribution ratio Dr (= Nr / (Nf + Nr)) is calculated by dividing the driving rear wheel drag Nr by the sum of the driving front wheel drag Nf and the driving rear wheel drag Nr (step S170). The front wheel load distribution ratio (= 1−Dr) obtained by subtracting the rear wheel load distribution ratio Dr from the value 1 is multiplied by the required braking torque T * to set the front wheel required torque Tf * required for the front wheels 63a and 63b and the rear wheel A required rear wheel torque Tr * required for the rear wheels 68a and 68b is set by multiplying the load distribution ratio Dr by the required braking torque T * (step S180).

  When the front and rear wheel required torques Tf * and Tr * are set in this way, the maximum value of the regenerative torque that can be output from the motor MG1 based on the input rotational speed Nm1 of the motor MG1 (the minimum value if the sign during regeneration is negative). The rated regenerative torque Tm2lim is derived as the maximum value of the regenerative torque that can be output from the motor MG2 based on the input rotational speed Nm2 of the motor MG2 (step S190). In order to derive the rated regenerative torques Tm1lim and Tm2lim, in the embodiment, the relationship between the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 and the rated regenerative torques Tm1lim and Tm2lim of the motors MG1 and MG2 is set in advance. The map is stored in the ROM 74, and when the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are given, the corresponding rated regenerative torques Tm1lim and Tm2lim are derived from the map. An example of the rated regenerative torque of the motor is shown in FIG.

  Subsequently, the set front wheel required torque Tf * is divided by the gear ratio G1 as the ratio of the rotation speed of the ring gear 32 to the rotation speed of the axle of the front wheels 63a, 63b, and multiplied by the gear ratio ρ of the power distribution and integration mechanism 30. The temporary motor torque Tm1tmp as the regenerative torque to be output from the motor MG1 is calculated and the rear wheel required torque Tr * is set as the ratio of the rotational speed of the motor MG2 to the rotational speed of the axles of the rear wheels 68a and 68b. The temporary motor torque Tm2tmp as the regenerative torque to be output from the motor MG2 is calculated by dividing by G2 (step S200), and the torque command Tm1 of the motor MG1 is set as a value obtained by limiting the temporary motor torque Tm1tmp with the derived rated regenerative torque Tm1lim. * Temporarily set with the rated regenerative torque Tm2lim derived and set Tatoruku Tm2tmp to set a torque command Tm2 * of the motor MG2 as a value obtained by limiting the (step S210).

  When the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set in this way, the torque command Tm1 * of the motor MG1 is converted from the front wheel required torque Tf * by the gear ratio ρ of the power distribution and integration mechanism 30 as shown in the following equation (3). A front wheel brake torque command Tbf * as a torque to be applied to the front wheels 63a, 63b by the hydraulic brake is set as a value obtained by subtracting the product of the gear ratio G1 and the rear wheel and the rear wheel as shown in the equation (4). The rear wheel brake torque command Tbr * is set as the torque to be applied to the rear wheels 68a and 68b by the hydraulic brake as a value obtained by subtracting the torque command Tm2 * of the motor MG2 set from the required torque Tr * and the gear ratio G2 (Step S220). The torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40, and the front and rear wheel brake torque commands Tbf * and Tbr * are transmitted to the brake ECU 61 (step S230), and this routine is terminated. Upon receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 switches the switching elements of the inverters 41 and 42 so that the torque of the torque command Tm1 * is output from the motor MG1 and the torque of the torque command Tm2 * is output from the motor MG2. Switching control is performed. When the brake ECU 61 receives the front and rear wheel brake torque commands Tbf * and Tbr *, a braking force corresponding to the front wheel brake torque command Tbf * is applied to the axles of the front wheels 63a and 63b, and the rear wheel brakes are applied to the axles of the rear wheels 68a and 68b. The brake actuator 69 is controlled so that a braking force corresponding to the torque command Tbr * is applied.

Tbf * = Tf * -G1 ・ Tm1 * / ρ (3)
Tbr * = Tr * -G2 ・ Tm2 * (4)

  According to the hybrid vehicle 20 of the embodiment described above, when braking at a relatively high vehicle speed, the carrier 34 of the power distribution and integration mechanism 30 is fixed to be non-rotatable by the clutch C1, and the motors MG1 and MG2 are fixed. Therefore, not only the motor MG2 but also the motor MG1 can generate large regenerative power, and more of the kinetic energy of the vehicle can be regenerated as electric power. Further, since the motors MG1 and MG2 are controlled so that the front and rear wheel required torques Tf * and Tr * set based on the vehicle weight distribution are output, the stability of the vehicle can be ensured.

  In the hybrid vehicle 20 of the embodiment, the processing when the vehicle speed V is equal to or greater than the threshold and the brake pedal 85 is depressed is described as a processing when the vehicle speed V is equal to or greater than the threshold regardless of the depression of the brake pedal 85. Alternatively, the processing may be performed when the brake pedal 85 is depressed relatively large regardless of the vehicle speed.

  In the hybrid vehicle 20 of the embodiment, the motor MG1 and MG2 are controlled so that the braking force by the motors MG1 and MG2 acts on the front and rear wheels, and the brake actuator 69 is controlled so that the braking force by the hydraulic brake acts on the front and rear wheels. However, when the required braking torque T * can be output by regenerative control of the motors MG1 and MG2, the braking force by the hydraulic brake may not be used. Absent.

  In the hybrid vehicle 20 of the embodiment, the torque commands Tm1 * and Tm2 * are set to control the motors MG1 and MG2 so that the front and rear wheel required torques Tf * and Tr * based on the vehicle weight distribution are output. As long as control is performed so that regenerative power is generated from the motor MG1 and the motor MG2, the motors MG1 and MG2 may be controlled by setting the torque commands Tm1 * and Tm2 * without being based on vehicle weight distribution.

  In the hybrid vehicle 20 of the embodiment, the front wheel required torque Tf * and the rear wheel required torque Tr * are set based on the vehicle weight distribution, and the torque command Tm1 * and the rear wheel required torque Tr * based on the front wheel required torque Tf * are set. Although the motors MG1 and MG2 are controlled by the torque command Tm2 * based on them, the maximum braking force that can be output to the front wheels 63a and 63b based on the vehicle weight distribution (the minimum braking force if the sign of the braking force is negative) The front wheel maximum braking force Nfmax and the rear wheel maximum braking force Nrmax that is the maximum braking force that can be output to the rear wheels 68a and 68b are set, and the torque command Tm1 * within the range of the front wheel maximum braking force Nfmax and the rear wheel maximum The motors MG1 and MG2 may be controlled by a torque command Tm2 * within the range of the braking force Nrmax. In this case, the braking time control routine of FIG. 6 may be executed instead of the braking time control routine of FIG. In the braking control routine of FIG. 6, the processing up to step S170 is the same as the processing up to step S170 of the braking control routine of FIG. When the front and rear wheel drag forces Nf and Nr are calculated (step S160), and the rear wheel load distribution ratio Dr is set (step S170), the maximum static friction coefficient between the road surface and the front and rear wheels is set to the front and rear wheel drag forces Nf and Nr. Multiplying μ by the conversion factor k sets the front and rear wheel maximum braking torques Nfmax and Nrmax (step S300). Here, the conversion coefficient k is for converting the braking force acting on the front and rear wheels into the braking torque for the axle. As the maximum static friction coefficient μ, for example, in a vehicle having a low μ road switch (not shown), when the low μ road switch is turned off, a static friction coefficient μ1 set in a normal state is used, and the low μ road switch is used. When is turned on, a static friction coefficient μ2 (<μ1) on a low μ road smaller than the static friction coefficient μ1 is used, or in a vehicle equipped with a raindrop sensor (not shown) when no raindrop is detected by the raindrop sensor The normal friction coefficient μ1 is used, and when a raindrop is detected by a raindrop sensor, the static friction coefficient μ2 on a low μ road is used, or the driving force acting on the wheel when the wheel slips due to idling The static friction coefficient calculated by the load based on the vehicle weight distribution at that time can be used. When the front and rear wheel maximum braking torques Nfmax and Nrmax are thus set, the rated regenerative torques Tm1lim and Tm2lim of the motors MG1 and MG2 are derived as in step S190 (step S310), and as much as possible of the required braking torque T * required for the axle. As shown in the following equation (5), the required braking torque T * is converted into the torque for the rotating shaft of the motor MG1 and the front wheel maximum braking torque Nfmax is set to the rotating shaft of the motor MG1 so as to output a lot of torque from the motor MG1. The largest torque (smallest as an absolute value) is selected from the converted torque for the motor MG1 and the rated regenerative torque Tm1lim of the derived motor MG1, and set as the torque command Tm1 * for the motor MG1 (step S320). When the torque command Tm1 * of the motor MG1 is set, as shown in the following equation (6), the torque that is insufficient with the torque command Tm1 * of the motor MG1 with respect to the required braking torque T * is calculated as the required rear wheel torque Tr *. The rear wheel required torque Tr * calculated as shown in the following equation (7) so as to output as much torque as possible from the rear wheel required torque Tr * from the motor MG2 is converted into torque with respect to the rotating shaft of the motor MG2. And the rear wheel maximum braking torque Nrmax converted to torque with respect to the rotation shaft of the motor MG2 and the rated regenerative torque Tm2lim of the motor MG2, the largest (absolutely smallest) torque is selected and the torque command Tm2 of the motor MG2 is selected. * Is set (step S330). When the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set in this way, the following equation (8) is used to output from the hydraulic brake a torque that is insufficient with the torque from the motors MG1 and MG2 with respect to the required braking torque T *. Thus, the required braking torque Tb * is calculated by subtracting the braking torque from the motor MG1 and the braking torque from the motor MG2 from the required braking torque T * (step S340), and the rear wheel load distribution ratio Dr is reduced from the value 1. The front wheel load distribution ratio (= 1-Dr) is multiplied by the calculated required brake torque Tb * to set the front wheel brake torque command Tbf *, and the rear wheel load distribution ratio Dr is multiplied by the required brake torque Tb * to rear wheel brake torque. Command Tbr * is set (step S350). Here, when the required braking torque T * can be output by the torque from the motors MG1, MG2, the brake torque command Tb * is set to a value of zero. When each set value is set, the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40, and the front and rear wheel brake torque commands Tbf * and Tbr * are transmitted to the brake ECU 61 (step S360). finish. The operation of the motor ECU 40 that has received the torque commands Tm1 * and Tm2 * and the operation of the brake ECU 61 that has received the front and rear wheel brake torque commands Tbf * and Tbr * have been described in the embodiment. In this way, as much torque as possible out of the required braking torque T * within the range of the front wheel maximum braking torque Nfmax and the rated regenerative torque Tm1lim is output from the front wheel side motor MG1, and the remaining torque is output to the rear wheel maximum braking torque Nrmax. By outputting from the rear wheel side motor MG2 within the range of the rated regenerative torque Tm2lim, more of the kinetic energy of the vehicle can be regenerated as electric power while ensuring the stability of the vehicle.

Tm1 * = max (ρ ・ T * / G1, ρ ・ Nfmax / G1, Tm1lim) (5)
Tr * = T * -G1 ・ Tm1 * / ρ (6)
Tm2 * = max (Tr * / G2, Nrmax / G2, Tm2lim) (7)
Tb * = T * -G1, Tm1 * / ρ-G2, Tm2 * (8)

  In the hybrid vehicle 20 of the embodiment, the clutch C1 is controlled so that the carrier 34 of the power distribution and integration mechanism 30 cannot rotate, and the motor MG1 and the motor MG2 are regeneratively controlled. 34 is provided on the engine 22 side with respect to the clutch C1, and the connection between the rotating shaft of the engine 22 and the carrier 34 is released by the connection release clutch, and then the carrier of the power distribution and integration mechanism 30 is connected. The clutch C1 may be controlled so that the motor 34 is not rotatable, and the motor MG1 and the motor MG2 may be regeneratively controlled. In this way, the carrier 34 of the power distribution and integration mechanism 30 can be made non-rotatable without stopping the operation of the engine 22. In this case, the engine 22 may be operated at idling speed, or the operation may be stopped.

  In the hybrid vehicle 20 of the embodiment, the power distribution and integration mechanism 30 is configured by the planetary gear having the three rotating elements of the sun gear 31, the ring gear 32, and the carrier 34. However, the two rotating elements of the two planetary gears are connected to each other. The power distribution and integration mechanism 30 may be configured to have four rotating elements obtained as described above, or the power distribution and integration mechanism 30 may be configured to have five or more rotating elements by connecting three or more planetary gears. It is good also as what to do. In this case, the power input / output to / from the sun gear 31 varies depending on the power input / output to / from the fourth and subsequent rotating elements, but when no power is input to and output from the fourth and subsequent rotating elements, or a constant power is input. When the power is being output, the power input / output to / from the sun gear 31 is determined by the power input / output to / from the ring gear 32 and the carrier 34. Therefore, if the carrier 34 is fixed in a non-rotatable manner, Electric power can be regenerated by the generated motor MG1. Can be fixed non-rotatable by clutch C1

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the front wheels 63a and 63b via the power distribution and integration mechanism 30. However, as illustrated in the hybrid vehicle 220 of the modified example of FIG. Has an inner rotor 232 connected to the crankshaft 26 via a clutch C1 and an outer rotor 234 connected to the front wheels 63a, 63b, and transmits a part of the power of the engine 22 to the front wheels and the remaining power. It is good also as what is provided with the counter-rotor electric motor 230 which converts this into electric power.

  In the embodiment, the hybrid vehicle 20 has been described. However, the hybrid vehicle 20 may be applied to a vehicle other than a vehicle such as a train, or a vehicle control method including a vehicle or a train may be used.

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

  The present invention can be used in the 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 control routine at the time of a braking performed by the electronic control unit for hybrids 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement braking torque setting. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of the power distribution and integration mechanism 30. It is explanatory drawing which shows an example of the rated regeneration torque of a motor. It is a flowchart which shows an example of a part of brake control routine of 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

20,220 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, 33 pinion gear, 34 carrier, 40 electronic control for motor Unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 52 electronic control unit for battery (battery ECU), 54 power line, 60, 65 gear mechanism, 61 electronic control unit for brake ( Brake ECU), 62, 67 differential gear, 63a, 63b front wheel, 64a, 64b, 66a, 66b brake wheel cylinder, 68a, 68b rear wheel, 69 brake actuator, 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, 89 G sensor 230 rotor motor, 232 inner rotor, 234 outer rotor, MG1, MG2 motor, C1, C2 clutch.

Claims (8)

An internal combustion engine;
A plurality of rotating elements including a first rotating element connected to an output shaft of the internal combustion engine and a second rotating element connected to a first axle; Electric power input / output means capable of inputting / outputting power to / from the first rotating element and the second rotating element;
Fixing means capable of fixing the first rotating element in a non-rotatable manner;
An electric motor capable of inputting and outputting power to a second axle different from the first axle;
A power storage means capable of exchanging power with the electric power drive input / output means and the electric motor;
Required driving force setting means for setting required driving force required for traveling;
When the set required driving force is a braking force and a predetermined condition is satisfied, the fixing means is controlled so that the first rotating element cannot rotate, and the power power input / output means and the electric motor Control means for controlling the power drive input / output means and the motor so that regenerative power is generated;
A vehicle comprising: The vehicle according to claim 1,
A first axle braking force to be output to the first axle and a second axle braking force to be output to the second axle based on a vehicle weight distribution with respect to the first axle and the second axle. Axle braking force setting means for setting,
A first target braking torque to be output from the electric power driving input / output means is set based on the set first axle braking force, and a first output to be output from the electric motor based on the set second axle braking force. 2 target braking torque setting means for setting the target braking torque;
With
The control means is configured to output the set first target braking torque from the electric power driving input / output means and output the set second target braking torque from the electric motor. A vehicle which is means for controlling the electric motor. The vehicle according to claim 1,
A first maximum braking force that can be output to the first axle and a second maximum braking force that can be output to the second axle based on a vehicle weight distribution with respect to the first axle and the second axle. Maximum braking force setting means to be set;
A first target braking torque to be output from the electric power driving input / output means is set within the range of the set first maximum braking force and is output from the motor within the set second maximum braking force. Target braking torque setting means for setting the power second target braking torque;
With
The control means is configured to output the set first target braking torque from the electric power driving input / output means and output the set second target braking torque from the electric motor. A vehicle which is means for controlling the electric motor. A vehicle according to any one of claims 1 to 3,
A braking force applying means capable of applying a braking force to the vehicle;
The control means is means for controlling the braking force applying means so that a braking force based on the set required driving force acts. The vehicle according to any one of claims 1 to 4,
Connection releasing means for connecting and releasing the connection between the output shaft of the internal combustion engine and the first rotating element;
The control means is means for controlling the connection release means so that the connection between the output shaft of the internal combustion engine and the first rotation element is released.   The power / power input / output means has a plurality of rotating elements including the first rotating element, the second rotating element, and a third rotating element connected to a rotating shaft, and any one of the plurality of rotating elements. The remaining rotating elements rotate based on the rotation of one rotating element, and power is supplied to the first rotating element, the second rotating element, and the third rotating element with a balance of power input to and output from the plurality of rotating elements. The vehicle according to any one of claims 1 to 5, wherein the vehicle includes: a plurality of rotating element power input / output means for inputting / outputting power; and a generator capable of inputting / outputting power to / from the rotating shaft.   2. The electric power input / output means is a counter-rotor electric motor that includes a first rotor as the first rotating element and a second rotor as the second rotating element and rotates relatively by electromagnetic action. The vehicle according to any one of 5 to 5. A plurality of rotating elements including an internal combustion engine, a first rotating element connected to the output shaft of the internal combustion engine, and a second rotating element connected to the first axle, with input and output of electric power and power The power axle input / output means capable of inputting / outputting power to / from at least the first rotating element and the second rotating element, the fixing means capable of fixing the first rotating element so as not to rotate, and the first axle are different. A vehicle control method comprising: an electric motor capable of inputting / outputting power to / from a second axle; and the electric power driving input / output means and an electric storage means capable of exchanging electric power with the electric motor,
When a braking force is required and a predetermined condition is established, the fixing means is controlled so that the first rotating element cannot rotate, and regenerative electric power is generated from the electric power input / output means and the electric motor. Controlling the power drive input / output means and the motor;
A method for controlling a vehicle.

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