JP2010111182A - Hybrid vehicle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress excessive rotation of a generator caused by rapid deceleration of a drive wheel without an electric storage device such as a secondary battery being over charged. <P>SOLUTION: When it is determined that a motor MG1 will reach excessive rotation and predetermined conditions are satisfied (S120, S240 to S260), an engine 22 and motors MG1 and MG2 are controlled so that power is output to a ring gear shaft 32a within a range that satisfies a condition that a value of rotation angular acceleration (ωm1/dt) of the motor MG1 becomes 0, a condition that a sum of power generated at the motor MG1 and power consumed at the motor MG2 becomes input limit Win when a battery is charged, and a condition that a sum of torque acting to the ring gear shaft by the power output from the motors MG1 and MG2 becomes less than required friction breaking torque FBT* (S280 to S300, S230). By this means, the excessive rotation of the motor MG1 can be suppressed without the battery 50 being over charged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

Conventionally, this type of hybrid vehicle is connected to an engine, a planetary gear mechanism in which a carrier is connected to a crankshaft of the engine and a ring gear is connected to an axle connected to a drive wheel, and a sun gear of the planetary gear mechanism. A first motor capable of generating electric power, a second motor that outputs power to the axle, and a battery that exchanges electric power with the first motor and the second motor, and slip caused by idling of the drive wheels is detected. In some cases, an allowable rotational speed for controlling the first motor is made smaller than when no slip of the driving wheel is detected (see, for example, Patent Document 1). In this hybrid vehicle, when slipping occurs due to idling of the drive wheels, the rotational speed of the drive wheels increases and the rotational speed of the engine also increases. Thereafter, when the gripping force of the driving wheel is restored, the rotational speed of the driving wheel rapidly decreases. At this time, the moment of inertia of the engine is much larger than the moment of inertia of the first motor, so that the rotational speed of the engine slightly decreases while the rotational speed of the first motor rapidly increases. Therefore, when the engine rotational speed is relatively high, the rotational speed of the first motor may exceed the allowable rotational speed. For this reason, in this hybrid vehicle, when the drive wheel slips, the allowable maximum number of rotations in the control of the first motor is set to a smaller value than usual, and the allowable number of rotations of the first motor is set. Regenerative torque is output from the first motor so as not to exceed the maximum rotational speed, and the first motor is prevented from over-rotating even if the rotational speed of the first motor suddenly increases when the gripping force of the drive wheels is restored.
JP 2007-20993 A

  However, in the above-described hybrid vehicle, the battery may be overcharged when the power generated by the first motor cannot be charged to the battery, such as when the battery is near full charge or when the battery temperature is low. Moreover, if the regenerative torque is not output from the first motor in order to avoid overcharging of the battery, the first motor will over-rotate.

  The main purpose of the hybrid vehicle and the control method thereof of the present invention is to suppress over-rotation of the generator caused by sudden deceleration of the drive wheels without overcharging the power storage device such as a secondary battery.

  The hybrid vehicle of the present invention and its control method employ the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An internal combustion engine, a generator capable of inputting / outputting power, an electric motor capable of inputting / outputting power to / from a drive shaft connected to drive wheels, a first rotating element, a second rotating element, and a third arranged in order in the alignment chart A planet having a rotating element, the first rotating element connected to the rotating shaft of the generator, the second rotating element connected to the output shaft of the internal combustion engine, and the third rotating element connected to the driving shaft. A hybrid vehicle comprising: a gear mechanism; a power storage means capable of exchanging electric power with the generator and the motor; and a braking means for applying a braking force to the vehicle based on a driver's operation,
A rotational speed detection means for detecting rotational speeds of at least two of the three shafts of the output shaft of the internal combustion engine, the rotational shaft of the generator, and the drive shaft;
Braking force calculating means for calculating a braking force applied to the vehicle by the braking means;
Based on the detected rotational speeds of at least two axes, the generator that estimates that the rotational speed of the generator is in an overspeed state exceeding the maximum rotational speed allowed for the generator due to sudden deceleration of the drive wheel Overspeed estimation means;
Input limit setting means for setting an input limit as the maximum allowable power when charging the power storage means based on the state of the power storage means;
When the generator overspeed estimation means estimates that the generator will be in an overspeed state and the calculated braking force is equal to or greater than a predetermined braking force, the generator rotational speed is The sum of the first condition in which the increase rate of the rotational speed of the generator is 0 at the maximum rotational speed and the power generated by the generator and the power consumed by the motor is the set input. The sum of the second condition that is within the limit, the torque that acts on the drive shaft by the power input / output from the generator, and the torque that acts on the drive shaft by the power input / output from the motor The internal combustion engine, the generator, and the motor are controlled so that power is output to the drive shaft within a range that satisfies the third condition that is less than the torque acting on the drive shaft by the calculated braking force. Realizes over-rotation suppression control And control means for,
It is a summary to provide.

  In the hybrid vehicle of the present invention, the generator overspeed estimation means estimates that the generator will be in an overspeed state, and the braking force applied to the vehicle by the braking means exceeds a predetermined braking force. Sometimes, the first condition that the rate of increase in the number of rotations of the generator is 0 when the number of rotations of the generator is the maximum allowable number of rotations, the power generated by the generator, and the power consumed by the motor Is the second condition that is within the range of the input limit as the maximum allowable power when charging the power storage means, the torque acting on the drive shaft by the power input / output from the generator, and the power input / output from the motor The internal combustion engine, the generator, and the electric motor so that power is output to the drive shaft within a range that satisfies the third condition in which the sum of the torque acting on the drive shaft is less than the torque acting on the drive shaft due to braking force. Control overtime Suppression control is executed. That is, when the drive shaft connected to the third rotating element suddenly decelerates, the moment of inertia at the output shaft of the internal combustion engine connected to the second rotating element is the moment of inertia at the output shaft of the generator connected to the first rotating element. The rotation speed of the generator is slightly decreased while the rotation speed of the internal combustion engine is slightly reduced because the first rotation element, the second rotation element, and the third rotation element are arranged in order in the collinear diagram. Soars. At this time, depending on the number of revolutions of the internal combustion engine, there is a possibility that an overspeed state exceeding the maximum number of revolutions allowed for the generator may occur. When the over-rotation state is estimated and the braking force applied to the vehicle by the braking means is in a predetermined rotational braking force state where the braking force is greater than or equal to the predetermined braking force, the first condition is that the generator speed exceeds the maximum rotational speed. The second condition is that the power storage means is not overcharged, and the third condition is the torque output from the generator to the drive shaft via the planetary gear mechanism, the torque output from the motor to the drive shaft, and the braking means. The internal combustion engine, the generator, and the electric motor are configured so that power is output to the drive shaft within a range that satisfies a condition in which the vehicle does not accelerate due to a torque that is the sum of the torque that acts on the drive shaft by the braking force applied to the vehicle. Be controlled. That is, the electric power generated by outputting a torque for reducing the rotational speed of the generator from the generator is consumed by the electric motor within a range where the vehicle does not accelerate. Thereby, the excessive rotation of the generator caused by the sudden deceleration of the drive wheels can be suppressed without overcharging the power storage means.

  Such a hybrid vehicle of the present invention includes a collision detection prediction unit that detects or predicts a vehicle collision, and the control unit detects the vehicle collision when the collision detection prediction unit detects or predicts a vehicle collision. Even at this time, it may be a means that does not execute the over-rotation suppression control. That is, before and after the collision of the vehicle, the braking force of the vehicle is prevented from being reduced by the power output to the drive shaft by the execution of the overspeed suppression control. As a result, it is possible to reduce the damage at the time of collision by prioritizing the deceleration of the vehicle.

  In the hybrid vehicle of the present invention, the first condition may be a means for controlling so as to satisfy a condition that the rate of increase in the number of revolutions of the generator is zero. Thereby, it is possible to prevent the rate of increase of the rotational speed from becoming zero or more before the rotational speed of the generator reaches the maximum rotational speed.

  Further, in the hybrid vehicle of the present invention, the rotation speed detection means is a means for detecting rotation speeds of the output shaft and the drive shaft of the internal combustion engine, and the generator overspeed estimation means is the detected output. When the rotational state of the planetary gear mechanism indicated by the rotational speed of the shaft and the rotational speed of the drive shaft becomes a value of 0 when the rotational speed of the drive shaft is suddenly decelerated, the rotational speed of the generator exceeds the maximum rotational speed. It is also possible to assume that the generator is assumed to be in an over-rotation state when the rotation state is within a preset range.

The hybrid vehicle control method of the present invention includes:
An internal combustion engine, a generator capable of inputting / outputting power, an electric motor capable of inputting / outputting power to / from a drive shaft connected to drive wheels, a first rotating element, a second rotating element, and a third arranged in order in the alignment chart A planet having a rotating element, the first rotating element connected to the rotating shaft of the generator, the second rotating element connected to the output shaft of the internal combustion engine, and the third rotating element connected to the driving shaft. A control method for a hybrid vehicle comprising: a gear mechanism; a power storage means capable of exchanging electric power with the generator and the motor; and a braking means for applying a braking force to the vehicle based on a driver's operation,
Based on the rotational speed of at least two of the three shafts of the output shaft of the internal combustion engine, the rotating shaft of the generator, and the driving shaft, the rotational speed of the generator is caused to the generator by rapid deceleration of the driving wheel. When it is estimated that an overspeed state exceeding an allowable maximum number of rotations will occur and the braking force applied to the vehicle by the braking means is equal to or greater than a predetermined braking force, the rotational speed of the generator is The sum of the first condition where the rate of increase in the number of revolutions of the generator is 0 at the maximum number of revolutions and the power generated by the generator and the power consumed by the motor is A second condition that is within a range of input restriction set as a maximum allowable power when charging the power storage means based on the state, a torque that acts on the drive shaft by the power input and output from the generator, and the Power input / output from the motor Further, power is applied to the drive shaft within a range satisfying the third condition in which the sum of the torque acting on the drive shaft is less than the torque acting on the drive shaft by the braking force applied to the vehicle by the braking means. Controlling the internal combustion engine, the generator and the motor to be output;
This is the gist.

  In this hybrid vehicle control method of the present invention, when the generator is estimated to be in an over-rotation state and the braking force applied to the vehicle by the braking means is greater than or equal to a predetermined braking force, The sum of the first condition in which the rate of increase in the number of revolutions of the generator is 0 when the number of revolutions of the generator is the maximum allowed and the power generated by the generator and the power consumed by the motor is The second condition that is within the range of input restriction as the maximum allowable power when charging the power storage means, the torque acting on the drive shaft by the power input / output from the generator, and the drive shaft by the power input / output from the motor The internal combustion engine, the generator, and the electric motor are controlled so that power is output to the drive shaft within a range that satisfies the third condition that the sum of the torque acting on the drive shaft is less than the torque that acts on the drive shaft by the braking force. . That is, when the drive shaft connected to the third rotating element suddenly decelerates, the moment of inertia at the output shaft of the internal combustion engine connected to the second rotating element is the moment of inertia at the output shaft of the generator connected to the first rotating element. The rotation speed of the generator is slightly decreased while the rotation speed of the internal combustion engine is slightly decreased because the first rotation element, the second rotation element, and the third rotation element are arranged in order in the collinear diagram. Soars. At this time, depending on the number of revolutions of the internal combustion engine, there is a possibility that an overspeed state exceeding the maximum number of revolutions allowed for the generator may occur. When the over-rotation state is estimated and the braking force applied to the vehicle by the braking means is a predetermined rotational braking force state in which the braking force is greater than or equal to the predetermined braking force, the first condition is that the generator rotational speed is the normal maximum rotational speed. The condition that the power storage means is not overcharged as the second condition, the torque that is output from the generator to the drive shaft through the planetary gear mechanism, the torque that is output from the electric motor to the drive shaft, and the braking as the third condition An internal combustion engine, a generator, and an electric motor so that power is output to the drive shaft within a range that satisfies a condition in which the vehicle is not accelerated by a torque that is the sum of the torque acting on the drive shaft by the braking force applied to the vehicle by the means Is controlled. In other words, the electric power generated by outputting the torque for reducing the rotational speed of the generator from the generator is consumed by the electric motor within a range where the vehicle does not accelerate. Thereby, the excessive rotation of the generator caused by the sudden deceleration of the drive wheels can be suppressed without overcharging the power storage means.

  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 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, A hybrid electronic control unit 70 for controlling the entire vehicle, an electronically controlled hydraulic brake unit (hereinafter simply referred to as “brake unit”) 90 capable of outputting a friction braking force, and the like 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 engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature from the temperature sensor 51 attached to the battery 50, and the like are input, and the data on the state of the battery 50 is electronically controlled by communication as necessary. Output to unit 70. Further, the battery ECU 52 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, or the battery ECU 52 based on the calculated remaining capacity SOC and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge 50, are calculated. The input / output limits Win and Wout of the battery 50 set basic values of the input / output limits Win and Wout based on the battery temperature, and the output limiting correction coefficient and the input limiting correction based on the remaining capacity SOC of the battery 50. The coefficient can be set, and the basic value of the set input / output limits Win and Wout can be multiplied by the correction coefficient.

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

  The brake unit 90 is attached to the brake master cylinder 91, the hydraulic (fluid pressure) brake actuator 92, the drive wheels 63a and 63b, and the driven wheels (not shown), and holds the brake disc to apply friction braking force to the corresponding wheels. Brake wheel cylinder pressure sensors 94a to 94d for detecting the hydraulic pressure (brake wheel cylinder pressure) of the brake wheel cylinders provided for each of the brake wheel cylinders 93a to 93d and the brake wheel cylinders 93a to 93d for driving the brake pads that can be applied. , A brake electronic control unit (hereinafter referred to as “brake ECU”) 95 for controlling the brake actuator 92, and the like. The brake actuator 92 is a pump or accumulator as a hydraulic pressure generation source (not shown), a master cylinder cut solenoid valve for controlling the communication state between the brake master cylinder 91 and the brake wheel cylinders 93a to 93d, and a pedal according to the depression amount of the brake pedal 85 A stroke simulator or the like that creates a reaction force against the pedaling force is provided, and a friction braking force can be applied to the drive wheels 63a and 63b and other driven wheels. Further, the brake ECU 95 detects a master cylinder pressure from a master cylinder pressure sensor (not shown), a brake wheel cylinder pressure from the brake wheel cylinder pressure sensors 94a to 94d, and a vehicle speed via a signal line (not shown). A vehicle speed V from the sensor 88, a brake pedal stroke BS from the brake pedal stroke sensor 86, a wheel speed from a wheel speed sensor (not shown), a steering angle from a steering angle sensor (not shown), and the like are input to the hybrid ECU 70 and the like. Various signals are exchanged by communication.

  When the brake pedal 85 is depressed by the driver, the brake ECU 95 uses the pedal depression force Fpd applied to the brake pedal 85 by the driver using the brake pedal stroke BS from the brake pedal stroke sensor 86 and a predetermined depression force setting map. And the required braking force BF * required by the driver is set based on the calculated pedal depression force Fpd. Further, the brake ECU 95 uses the set required braking force BF *, the vehicle speed V from the vehicle speed sensor 88, and a predetermined distribution ratio setting map to request the required drive system braking force RBF * (= d ×) for the motor MG2 and the engine 22. BF *) and the required friction braking force FBF * (= (1-d) × BF *) for the brake unit 90 (brake actuator 92) are set. Then, the brake ECU 95 calculates the required friction braking obtained by multiplying the required driving system braking torque RBF * obtained by multiplying the required driving system braking force RBF * by the predetermined conversion coefficient and the required friction braking force FBF * by the predetermined conversion coefficient. Torque FBT * is transmitted to the hybrid ECU 70 and acts on the hybrid vehicle 20 based on the drive system braking torque and the required friction braking force FBF * output from the motor MG2 and the engine 22 obtained based on the signal from the hybrid ECU 70. The brake actuator 92 is controlled so that the friction braking force according to the share of the braking force to be applied by the brake unit 90 acts on the drive wheels 63a and 63b and the driven wheels (not shown). In the embodiment, the required braking force setting map is predetermined and stored in the ROM of the brake ECU 95 so as to define the relationship between the pedal depression force Fpd by the driver and the required braking force BF *. FIG. 2 shows an example of the required braking force setting map. In the embodiment, the distribution ratio setting map defines the relationship between the vehicle speed V and the distribution ratio d between the drive braking force by the motor MG2 and the engine 22 and the friction braking force by the brake unit 90 with respect to the required braking force BF *. Thus, it is created in advance and stored in the ROM of the brake ECU 95. FIG. 3 shows an example of the distribution ratio setting map.

  Further, the hybrid vehicle 20 of the present embodiment is provided with a collision detection unit 100 for detecting the collision of the vehicle and the possibility of the collision. The collision detection unit 100 includes a G sensor that detects acceleration generated in the vehicle, a radar sensor that recognizes an object existing in front of the vehicle, a camera, and the like, and transmits signals from these sensors and cameras to the hybrid electronic control unit 70. is doing. The hybrid electronic control unit 70 that has received such a signal determines the collision of the vehicle based on the acceleration from the G sensor, or processes the signal from the radar sensor or camera to detect the collision with an object existing in front of the vehicle. A process of determining whether or not there is a possibility is executed.

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

  Next, when the accelerator pedal 83 is released and the brake pedal 85 is depressed during the operation of the hybrid vehicle 20 of the embodiment thus configured, in particular, while traveling with the operation of the engine 22. The operation will be described. FIG. 4 is a flowchart showing an example of a braking drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec) when the accelerator is off and the brake is on.

  When the braking drive control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the vehicle speed V from the vehicle speed sensor 88, the engine speed Ne, the motors MG1, MG2 engine speeds Nm1, Nm2, and the battery. Processing for inputting data necessary for control, such as 50 input / output limits Win, Wout, required drive system braking torque RBT *, required friction braking torque FBT *, and collision detection flag F, is executed (step S100). Here, the rotational speed Ne of the engine 22 is calculated based on a signal from the crank position sensor 140 and is input from the engine ECU 24 by communication. Further, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. It was supposed to be. The requested drive system braking torque RBT * and the requested friction braking torque FBT * are set by the brake ECU 95 and input by communication. The collision detection flag F is set to 1 when the hybrid electronic control unit 70 determines a collision or the possibility of a collision based on a signal from the collision detection unit 100, and is set to 0 at other normal times. Flag.

  When the data is input in this way, a motor rotation change amount ΔNm2 as a change amount of the rotation speed Nm2 of the motor MG2 is calculated by subtracting the motor rotation speed Nm2 input this time from the motor rotation speed Nm2 input during the previous execution of this routine (step). S110), the calculated motor rotation change amount ΔNm2 is compared with a predetermined negative value threshold value ΔNref (step S120). Here, the motor rotation change amount ΔNm2 basically becomes a negative value during deceleration of the vehicle, and when the motor rotation change amount ΔNm2 is smaller than the threshold value ΔNref, it is determined that the drive wheels 63a and 63b may be locked. Can do.

  When the motor rotation change amount ΔNm2 is larger than the threshold value ΔNref, it is determined that the driving wheels 63a and 63b are not locked, and the axle is used as an axle at the time of braking when the accelerator is off (Acc = 0%) based on the input vehicle speed V. A ring torque shaft 32a as an axle is set by setting a base torque Tb as a driving force to be constantly output to the ring gear shaft 32a and adding the required driving system braking torque RBT * input at step S100 to the set base torque Tb. Is set to a required torque (required braking torque) Tr * to be output (step S130). Here, in the embodiment, the base torque Tb is stored in the ROM 74 as a base torque setting map in which the relationship between the vehicle speed V and the base torque Tb is predetermined, and the base torque Tb corresponding to the given vehicle speed V is stored. Is derived and set from the map. FIG. 5 shows an example of the base torque setting map.

  When the required torque Tr * is set, the target rotational speed Ne * of the engine 22 is set based on the vehicle speed V (step S140), and the vehicle speed V is compared with a predetermined vehicle speed Vfc (step S150). Here, in the embodiment, the relationship between the vehicle speed V and the target rotational speed Ne * is determined in advance and stored in the ROM 74 as a target rotational speed setting map, and when the vehicle speed V is given, the corresponding target rotational speed is stored from the stored map. The number Ne * was derived and set. When the vehicle speed V is relatively high, the target rotational speed Ne * is set so that the engine 22 in a fuel-cut state is motored by the motor MG1, so that the braking torque (friction torque) by the engine brake is applied from the engine 22 to the ring gear shaft 32a. The output speed is determined to increase as the vehicle speed V increases. When the vehicle speed V is relatively low, the idle speed Nidle (the rotation speed at which the engine 22 can be stably operated independently regardless of the vehicle speed V). For example, it is determined to be 800 rpm or 1200 rpm. FIG. 6 shows an example of the target rotation speed setting map. The predetermined vehicle speed Vfc is set as a vehicle speed at which the engine brake output from the engine 22 is stopped and fuel is supplied to the engine 22, and is set to a relatively low vehicle speed of about 20 to 30 km / h, for example. ing.

  Thus, when the vehicle speed V is compared with the predetermined vehicle speed Vfc and it is determined that the vehicle speed V is less than the predetermined vehicle speed Vfc, a self-sustained operation command for autonomously operating the engine 22 is transmitted to the engine ECU 24 (step S160), and the motor MG1. A value 0 is set in the torque command Tm1 * (step S170). Here, the engine ECU 24 that has received the self-sustained operation command performs intake air amount control, fuel injection control, ignition control, etc. so that the engine 22 operates autonomously at the target rotational speed Ne * (in the embodiment, the idle rotational speed Nidle). Control.

  On the other hand, when it is determined that the vehicle speed V is equal to or higher than the predetermined vehicle speed Vfc (step S150), a fuel cut command for stopping the fuel supply of the engine 22 is transmitted to the engine ECU 24 (step S180), the target rotational speed Ne * and the ring gear. The target rotational speed Nm1 * of the motor MG1 is calculated by the following equation (1) using the rotational speed (Nm2 / Gr) of the shaft 32a and the gear ratio ρ of the power distribution and integration mechanism 30, and the calculated target rotational speed Nm1 * Based on the current rotational speed Nm1, a torque command Tm1 * of the motor MG1 is calculated by the equation (2) (step S190). Here, the engine ECU 24 that has received the fuel cut command stops the fuel injection control and the like in the engine 22. Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 7 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30 when the vehicle speed V is equal to or higher than the predetermined vehicle speed Vfc. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by multiplying the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term. Here, the torque Tm1 output from the motor MG1 is a torque output from the motor MG1 for motoring so that the rotational speed Ne of the engine 22 is maintained at the target rotational speed Ne *, and is output from the motor MG1. The torque (−Tm1 / ρ) transmitted to the ring gear shaft 32a via the power distribution and integration mechanism 30 corresponds to the braking torque generated by the engine brake from the engine 22.

Nm1 * ＝ Ne * ・ (1 + ρ) / ρ−Nm2 / (Gr ・ ρ) (1)
Tm1 * = previous Tm1 * + k1 (Nm1 * −Nm1) + k2∫ (Nm1 * −Nm1) dt (2)

  Subsequently, the torque command Tm1 * divided by the gear ratio ρ of the power distribution and integration mechanism 30 is added to the required torque Tr * and further divided by the gear ratio Gr of the reduction gear 35 to temporarily output the torque to be output from the motor MG2. Is obtained by multiplying the input / output limits Win and Wout of the battery 50 and the torque command Tm1 * by the current rotational speed Nm1 of the motor MG1. Torque limits Tm2min and Tm2max as upper and lower limits of the torque that may be output from the motor MG2 by dividing the deviation from the power consumption (generated power) of the motor MG1 by the rotational speed Nm2 of the motor MG2 are expressed by the following equations (4) and (4): While calculating by (5) (step S210), the set temporary motor torque Tm2tmp is set to the torque limit T by the following equation (6). 2min, and limited by Tm2max to set a torque command Tm2 * of the motor MG2 (step S220).

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (3)
Tm2min ＝ (Win-Tm1 * ・ Nm1) / Nm2 (4)
Tm2max ＝ (Wout-Tm1 * ・ Nm1) / Nm2 (5)
Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (6)

  The torque command Tm1 * of the motor MG1 and the torque command Tm2 * of the motor MG2 set in this way are transmitted to the motor ECU 40 (step S230), and the braking drive control routine is temporarily terminated. Receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. . By such control, the motor 22 is driven at the target rotational speed Ne * or is driven independently while the required torque Tr * is output to the ring gear shaft 32a as the drive shaft within the range of the input / output limits Win and Wout of the battery 50. can do.

  On the other hand, when the motor rotation change amount ΔNm2 is equal to or smaller than the threshold value ΔNref in step S120, it is determined that the driving wheels 63a and 63b may be locked, and the rotation speed Nm1 of the motor MG1 is allowed to be the maximum motor MG1. It is determined whether or not an excessive rotation exceeding the rotation speed is reached (step S240). Here, in the embodiment, whether or not the motor MG1 is over-rotated is determined based on the rotational state of the carrier 34 and the ring gear 32 of the power distribution and integration mechanism 30 indicated by the engine speed Ne and the motor speed Nm2. Of these, the range of the rotational state in which it is estimated that the rotational speed Nm1 of the motor MG1 may exceed the normal maximum rotational speed allowed for the motor MG1 is determined in advance as an overspeed estimation region, and the rotational speed of the carrier 34 (= Ne ) And the rotational speed of the ring gear 32 (= Nm2 / Gr) are within the overspeed estimation region, it is determined that the motor MG1 reaches overspeed. Here, in FIG. 8, when the rotational speed of the ring gear 32 suddenly decelerates to a value of 0 (when the drive wheels 63a and 63b are locked), the power for explaining the state in which the rotational speed Nm1 of the motor MG1 is over-rotated. An example of an alignment chart of the distribution and integration mechanism 30 is shown. In the drawing, the solid line shows a state before the rotational speed of the ring gear 32 is suddenly decelerated, and the dotted line shows a state when the rotational speed of the ring gear 32 is suddenly decelerated to reach a value of zero. As shown in the figure, when the rotation speed of the ring gear 32 is suddenly decelerated, the increase amount of the rotation speed of the sun gear 31 is very large compared to the decrease amount of the rotation speed of the carrier 34. The rotational speed changes in this way because the inertia moment of the engine 22 connected to the carrier 34 is very large compared to the inertia moment of the motor MG1 connected to the sun gear 31, so the rotational speed of the carrier 34 changes. This is because the number of rotations of the sun gear 31 is likely to change while it is difficult. The reason why the rotational speed of the sun gear 31 rapidly increases and the rotational speed Nm1 of the motor MG1 may overspeed is that the rotational speed of the carrier 34 and the rotational speed Nm2 of the motor MG2 coincide with the rotational speed Ne of the engine 22. This is when the rotational speed of the ring gear 32 obtained by dividing by the gear ratio Gr of the reduction gear 35 is a relatively large value. In the embodiment, as shown in FIG. 9, the upper and lower limits of the number of rotations allowed for the sun gear 31 (motor MG1) (the maximum rotation speeds on the positive side and the negative side) and the upper and lower limits of the number of rotations allowed for the pinion gear 33 Power distribution integration mechanism 30 (ring gear) determined from (maximum normal rotation speed on the positive side and negative side) and upper and lower limits (range from 0 to the maximum normal rotation speed) allowed for the carrier 34 (engine 22) 32 and the carrier 34), an area in which the motor MG1 may exceed the normal maximum rotational speed when the ring gear shaft 32a is suddenly decelerated (locked) (the hatched area in FIG. 9). Is determined by experiment and analysis, a determination threshold for the other is set based on one of the rotational speed Ne of the engine 22 and the rotational speed Nm2 of the motor MG2, and the rotational speed By comparing the other of the determination threshold value e and the rotation speed Nm2, it is determined whether there is a risk that the motor MG1 reaches the overspeed.

  When it is determined that the motor MG1 may be over-rotated (step S240), the required friction braking torque FBT * is compared with the predetermined torque Tref (step S250), and when the required friction braking torque FBT * is equal to or greater than the predetermined torque Tref. Then, the value of the collision detection flag F is checked (step S260). Then, when it is determined that the motor MG1 does not cause excessive rotation (step S240), or when the required friction braking torque FBT * is less than the predetermined torque Tref (step S250), it is determined whether a vehicle collision or a collision may occur. When the collision detection flag F is set to the value 1 (step S260), the engine 22 is requested within the range of the input / output limits Win and Wout of the battery 50 while motoring or autonomously operating at the target rotational speed Ne *. The braking drive control routine is temporarily terminated by performing the processing in steps S130 to S230 of the braking drive control routine so that the torque Tr * is output to the ring gear shaft 32a serving as the drive shaft. In addition, as the predetermined torque Tref, a sufficiently large value can be used to execute the processes of steps S270 to S300 and S230 described later.

Further, when there is a possibility that the motor MG1 will over-rotate and the required friction braking torque FBT * is equal to or greater than the predetermined torque Tref and the collision detection flag F is 0 (steps S240 to S260), the fuel supply of the engine 22 to the engine ECU 24 is stopped. A fuel cut command is transmitted (step S270), and the condition that the rotational angular acceleration (ωm1 / dt) of the motor MG1 obtained based on the equation of motion of the sun gear 31 of the power distribution and integration mechanism 30 is 0 is shown. The following formula (7) (where “κ” in formula (7) is as shown in the following formula (8)) and the sum of electric power input / output by the motor MG1 and the motor MG2 is the input / output limit Win. Motor torques Tm1 and Tm2 satisfying the following equation (9) indicating equal conditions are set as motor temporary torques Tm1tmp and Tm2tmp. (Step S270). In Equation (7), ωm2 is the rotational angular velocity of the rotating shaft of the motor MG2, Ie is the moment of inertia on the crankshaft 26 side from the power distribution integration mechanism 30, and Im1 is the motor MG1 from the power distribution integration mechanism 30. Im2 is the moment of inertia on the motor MG2 side from the power distribution and integration mechanism 30. As the torque Te from the engine 22 in the equation (7), in the embodiment, the friction torque of the engine 22 estimated based on the rotational speed Ne of the engine 22 is obtained and stored in advance through experiments or the like, and the rotational speed Ne. Is given, the corresponding friction torque value is derived and used as the torque Te. Further, the required friction braking torque FBT * can be used for the friction braking torque FBT. Thus, the motor temporary torques Tm1tmp and Tm2tmp are not increased in the rotational speed Nm1 of the motor MG1, and the sum of the electric power generated by the motor MG1 and the electric power consumed by the motor MG2 is within the range of the input limit Win. Can be determined.

  Thus, when the motor temporary torques Tm1tmp and Tm2tmp of the motors MG1 and MG2 are set, the required friction braking torque FBT *, the motor temporary torque Tm1tmp, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Gr of the reduction gear 35 are used. The torque limit Tm2max as the upper limit of the torque that may be output from the motor MG2 is calculated by the following equation (10) (step S290), the motor temporary torque Tm1tmp is set to the torque command Tm1 * of the motor MG1, and the set motor temporary Torque Tm2tmp is limited by torque limit Tm2max according to the following equation (11), and torque command Tm2 * for motor MG2 is set (step S290). As a result, the sum of the torque output from the motor MG1 to the ring gear shaft 32a via the power distribution and integration mechanism 30 and the torque output from the motor MG2 to the ring gear shaft 32a is set as a torque less than the required friction braking torque FBT *. Torque command Tm2 * can be set so that hybrid vehicle 20 does not accelerate.

Tm2max = (FBT * + Tm1tmp / ρ) / Gr (10)
Tm2 * = min (Tm2tmp, Tm2max) (11)

  When the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are set in this way, the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S230), and the braking drive control routine is terminated. Receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. .

  FIG. 10 shows the rotational speeds and torques of the rotating elements of the power distribution and integration mechanism 30 before and after the sudden braking in which the driver depresses the brake pedal 85 strongly while the hybrid vehicle 20 is traveling at a relatively high vehicle speed. An example of a collinear diagram showing the dynamic relationship with The dotted line in the figure indicates the rotation speed of each rotating element of the power distribution and integration mechanism 30 before sudden braking, and the solid line in the figure indicates the rotation speed of each rotation element of the power distribution and integration mechanism 30 during sudden braking. Also, two upward bold arrows on the R axis indicate the torque (−Tm1 / ρ) that is output from the motor MG1 upon sudden braking and acts on the ring gear shaft 32a via the power distribution and integration mechanism 30, and the motor MG2. The torque (Tm2 · Gr) acting on the ring gear shaft 32a via the reduction gear 35 is shown, and the downward bold arrow on the R-axis indicates the friction control output from the brake unit 90 due to sudden braking. A friction braking torque FBT acting on the ring gear shaft 32a by power is shown. While the hybrid vehicle 20 is traveling at a relatively high vehicle speed, the driver depresses the brake pedal 85 strongly. In the above-described braking drive control routine, the motor rotation change amount ΔNm2 is equal to or less than the threshold value ΔNref, and the motor MG1. If the required friction braking torque FBT * is equal to or greater than the predetermined torque Tref and the collision detection flag F is determined to be 0 (steps S120, S240 to S260), steps S270 to S300 are performed. Through the above process, the condition that the rotational angular velocity (ωm1 / dt) of the motor MG1 is 0, the condition that the power input / output by the motors MG1 and MG2 is equal to the input limit Win of the battery 50, and the output from the motors MG1 and MG2 are output. The torque acting on the ring gear shaft 32a is the required friction braking torque FBT * The condition and the torque command Tm1 * that is set so as to satisfy the composed, motors MG1, MG2 is driven and controlled in accordance with Tm2 *. As a result, as shown in the drawing, a negative torque (downward torque in the figure) is output from the motor MG1, so that an increase in the rotational speed Nm1 is suppressed. The motor MG2 consumes the electric power generated by the motor MG1 within a range where the electric power supplied to the battery 50 is equal to the input limit Win and the hybrid vehicle 20 is not accelerated by the torque acting on the ring gear shaft 32a. Output positive torque (upward torque in the figure). Such control is repeatedly executed until the motor rotation change amount ΔNm2 of the motor MG2 becomes larger than the threshold value ΔNref or the possibility of over-rotation of the motor MG1 is eliminated. Thereby, in the hybrid vehicle 20 of the embodiment, even if the motor MG1 may over-rotate, the over-rotation of the motor MG1 can be suppressed without overcharging the battery 50.

  According to the hybrid vehicle 20 of the embodiment described above, when it is determined that the motor MG1 is over-rotated and the required friction braking torque FBT * is greater than the predetermined torque Tref, the rotational angular acceleration (ωm1 / dt) of the motor MG1. And the condition that the sum of the power generated by the motor MG1 and the power consumed by the motor MG2 is equal to the input limit Win when charging the battery 50, and the power output from the motor MG1. Thus, torque is applied to the ring gear shaft 32a within a range that satisfies the condition that the sum of the torque acting on the ring gear shaft 32a and the torque acting on the ring gear shaft 32a by the power output from the motor MG2 is less than the required friction braking torque FBT *. Since the engine 22 and the motors MG1, MG2 are controlled so as to be output, the battery 50 Driving wheels 63a without being overcharged, over-rotation of the motor MG1 caused by rapid deceleration of 63b can be suppressed.

  Further, the hybrid vehicle 20 of the embodiment includes a collision detection unit 100 that detects the collision of the vehicle and the possibility of the collision. When the collision detection unit 100 detects the collision of the vehicle or the possibility of the collision, the motor MG1 is activated. Even when it is determined that overspeed is reached and the required friction braking torque FBT * is greater than the predetermined torque Tref, control for suppressing overspeed of the motor MG1 is not executed, so that it is output from the motors MG1 and MG2 before and after the vehicle collision. Therefore, it is possible to prevent the braking force of the vehicle from being reduced by the torque acting on the ring gear shaft 32a by the motive power, and to reduce the damage at the time of collision by giving priority to the deceleration of the vehicle.

  In the hybrid vehicle 20 according to the embodiment, when it is determined that the motor MG1 is over-rotated and the required friction braking torque FBT * is greater than the predetermined torque Tref, the rotational angular acceleration (ωm1 / dt) of the motor MG1 becomes 0. The condition is set so that the rotational angular acceleration (ωm1 / dt) of the motor MG1 becomes smaller after the rotational speed Nm1 of the motor MG1 reaches the normal maximum rotational speed allowed by the motor MG1 or a value slightly smaller than this. It is also possible to satisfy the condition of value 0.

  In the hybrid vehicle 20 of the embodiment, the condition that the sum of the power generated by the motor MG1 and the power consumed by the motor MG2 is equal to the input limit Win when charging the battery 50 is satisfied. However, the condition that the sum of the power generated by the motor MG1 and the power consumed by the motor MG2 is slightly smaller than the input limit Win when charging the battery 50 or a value of 0 may be satisfied. .

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a, but the power of the motor MG2 is changed as in the hybrid vehicle 120 of the modified example illustrated in FIG. May be connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 11) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “internal combustion engine”, the motor MG1 corresponds to the “generator”, the motor MG2 connected to the ring gear shaft 32a as the drive shaft corresponds to the “electric motor”, and the sun gear 31 The power distribution and integration mechanism 30 in which the motor MG1 is connected, the crankshaft 26 of the engine 22 is connected to the carrier 34, and the ring gear shaft 32a is connected to the ring gear 32 corresponds to a “planetary gear mechanism”, and exchanges power with the motors MG1 and MG2. Rotating position detection sensors 43 and 44 for detecting the rotational position of the rotors of the motors MG1 and MG2 and the rotational position detecting sensor. Motor ECU 40 for calculating the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the signals from 43, 44 The engine ECU 24 that calculates the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26 corresponds to “rotational speed detection means”, and is a request given from the brake unit 90 to the vehicle. The brake ECU 95 that sets the friction braking force FBF * and calculates the required friction braking torque FBT * based on the set required friction braking force FBF * corresponds to the “braking force calculating means”, and the rotational speed Nm2 of the motor MG2 The hybrid electronic control unit 70 that executes the process of step S240 of the braking-time drive control routine of FIG. 4 that estimates the overspeed of the motor MG1 based on the engine speed Ne and the overspeed estimation region of FIG. It corresponds to “generator overspeed estimation means” and is based on the remaining capacity SOC and the battery temperature Tb. It corresponds to the battery ECU 52 “input limit setting means” that calculates the input limit Win, which is the maximum allowable power that may charge the battery 50, and it is estimated that the motor MG1 is over-rotated and the required friction braking torque FBT *. Is equal to or greater than the predetermined torque Tref and the collision detection flag F has a value of 0, the condition that the rotational angular acceleration (ωm1 / dt) of the motor MG1 has a value of 0 and the sum of electric power input and output by the motor MG1 and the motor MG2 Satisfies the condition that is equal to the input / output limit Win and limits the torque output from the motor MG2 with the torque limit Tm2max so as not to accelerate the vehicle, and sets torque commands Tm1 * and Tm2 * and transmits them to the motor ECU 40 The hybrid which executes the processing of steps S270 to S300 and S230 of the braking drive control routine of FIG. The engine ECU 24 for controlling the engine 22 based on the engine electronic control unit 70, the engine fuel cut command, and the motor ECU 40 for controlling the motors MG1, MG2 based on the torque commands Tm1 *, Tm2 * correspond to “control means”. . Further, the collision detection unit 100 for detecting the collision of the vehicle and the possibility of the collision is processed, and a signal from the collision detection unit 100 is processed to determine whether there is a possibility of a collision with an object existing in front of the vehicle. The hybrid electronic control unit 70 that executes the processing to correspond to “collision detection prediction means”.

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. The “generator” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of generator as long as it can input and output power, such as an induction motor. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any motor that can input and output power to the drive shaft, such as an induction motor. The “planetary gear mechanism” is not limited to the power distribution and integration mechanism 30 in which the motor MG1 is connected to the sun gear 31, the crankshaft 26 of the engine 22 is connected to the carrier 34, and the ring gear shaft 32a is connected to the ring gear 32. And a first rotating element, a second rotating element, and a third rotating element that are arranged in order in the nomograph, wherein the first rotating element is connected to the rotating shaft of the generator, and the second rotating element is connected to the internal combustion engine. As long as it is connected to the output shaft and the third rotating element is connected to the drive shaft, any configuration may be used. The “storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it can exchange power with a generator and an electric motor such as a capacitor. The “braking means” is not limited to the brake system 90, and any braking means may be used as long as it applies a braking force to the vehicle based on the operation of the driver. As the “rotation speed detection means”, the motor ECU 40 that calculates the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotation position detection sensors 43 and 44, and the engine 22 based on signals from the crank position sensor. Is not limited to the engine ECU 24 for calculating the rotational speed Ne of the engine, but at least two of the three axes of the output shaft of the internal combustion engine, the rotating shaft of the generator, and the driving shaft connected to each rotating element of the planetary gear mechanism. As long as it detects the number of rotations of the shaft, it may be anything. As the “braking force calculation means”, the required friction braking force FBF * to be applied to the vehicle from the brake unit 90 is set, and the required friction braking torque FBT * is calculated based on the set required friction braking force FBF *. The present invention is not limited, and any calculation is possible as long as the braking force applied to the vehicle by the braking means is calculated, such as calculating the required friction braking torque FBT * from the equation of motion of the ring gear 32 of the power distribution and integration mechanism 30. It doesn't matter. The “generator overspeed estimation means” is limited to one that estimates the overspeed of the motor MG1 based on the speed Nm2 of the motor MG2, the speed Ne of the engine 22, and the overspeed estimation region of FIG. Instead, any method may be used as long as it is estimated that the generator is over-rotated due to sudden deceleration of the drive wheels based on the rotational speeds of at least two axes detected by the rotational speed detection means. The “input limit setting means” is not limited to the one that calculates the input limit Win based on the remaining capacity SOC and the battery temperature Tb. In addition to the remaining capacity (SOC) and the battery temperature Tb, for example, the battery 50 As long as the input restriction is set based on the state of the power storage means, such as a calculation based on the internal resistance of the battery, any method may be used. The “control means” is not limited to the combination of the hybrid electronic control unit 70, the engine ECU 24, and the motor ECU 40, and may be any unit that performs over-rotation suppression control in a predetermined rotational braking state. It may be configured by one electronic control unit. The “collision detection predicting means” is not limited to the combination of the collision detection unit 100 and the hybrid electronic control unit 70, and may be anything as long as it detects or predicts a vehicle collision. Absent.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  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 manufacturing industry of hybrid vehicles.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is explanatory drawing which shows an example of the map for request | requirement braking force setting. It is explanatory drawing which shows an example of the map for distribution ratio setting. 4 is a flowchart showing an example of a braking-time drive control routine executed by a hybrid electronic control unit 70; It is explanatory drawing which shows an example of the map for base torque setting. It is explanatory drawing which shows an example of the map for target rotation speed 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. FIG. FIG. 6 is an explanatory diagram showing an example of a collinear diagram of the power distribution and integration mechanism 30 for explaining a state in which the rotation speed Nm1 of the motor MG1 becomes excessive when the rotation speed of the ring gear 32 suddenly decreases to a value of 0. . It is explanatory drawing which shows an example of an overspeed estimation area | region. While the hybrid vehicle 20 is traveling at a relatively high vehicle speed, the dynamics of the rotational speed and torque of each rotating element of the power distribution and integration mechanism 30 before and after sudden braking in which the driver depresses the brake pedal 85 strongly. It is explanatory drawing which shows an example of the collinear diagram which shows a special relationship. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification.

Explanation of symbols

  20, 120 Hybrid vehicle, 22 Engine, 26 Crankshaft, 28 Damper, 30 Power distribution and integration mechanism, 31 Sun gear, 32 Ring gear, 32a Ring gear shaft, 33 Pinion gear, 34 Carrier, 35 Reduction gear, 40 Electronic control unit for motor (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b drive Wheel, 64a, 64b Wheel, 70 Hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 A Cell pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 88 vehicle speed sensor, 90 electronically controlled hydraulic brake unit (brake unit), 91 brake master cylinder, 92 brake actuator, 93a to 93d brake wheel cylinder, 94a to 94d Brake wheel cylinder pressure sensor, 95 Brake electronic control unit (brake ECU), MG1, MG2 motor.

Claims (5)

An internal combustion engine, a generator capable of inputting / outputting power, an electric motor capable of inputting / outputting power to / from a drive shaft connected to drive wheels, a first rotating element, a second rotating element, and a third arranged in order in the alignment chart A planet having a rotating element, the first rotating element connected to the rotating shaft of the generator, the second rotating element connected to the output shaft of the internal combustion engine, and the third rotating element connected to the driving shaft. A hybrid vehicle comprising: a gear mechanism; a power storage means capable of exchanging electric power with the generator and the motor; and a braking means for applying a braking force to the vehicle based on a driver's operation,
A rotational speed detection means for detecting rotational speeds of at least two of the three shafts of the output shaft of the internal combustion engine, the rotational shaft of the generator, and the drive shaft;
Braking force calculating means for calculating a braking force applied to the vehicle by the braking means;
Based on the detected rotational speeds of at least two axes, the generator that estimates that the rotational speed of the generator is in an overspeed state exceeding the maximum rotational speed allowed for the generator due to sudden deceleration of the drive wheel An overspeed estimation means;
Input limit setting means for setting an input limit as the maximum allowable power when charging the power storage means based on the state of the power storage means;
When the generator overspeed estimation means estimates that the generator will be in an overspeed state and the calculated braking force is equal to or greater than a predetermined braking force, the generator rotational speed is The sum of the first condition in which the increase rate of the rotational speed of the generator is 0 at the maximum rotational speed and the power generated by the generator and the power consumed by the motor is the set input. The sum of the second condition that is within the limit, the torque that acts on the drive shaft by the power input / output from the generator, and the torque that acts on the drive shaft by the power input / output from the motor The internal combustion engine, the generator, and the motor are controlled so that power is output to the drive shaft within a range that satisfies the third condition that is less than the torque acting on the drive shaft by the calculated braking force. Realizes over-rotation suppression control And control means for,
A hybrid car with The hybrid vehicle according to claim 1,
A collision detection and prediction means for detecting or predicting a collision of the vehicle,
The control means is means for not executing the overspeed suppression control even in the predetermined rotational braking state when a collision of a vehicle is detected or predicted by the collision detection prediction means.
Hybrid car.   The hybrid vehicle according to claim 1 or 2, wherein the control means is a means for controlling the first condition to satisfy a condition that an increase rate of the rotational speed of the generator is a value of zero. A hybrid vehicle according to any one of claims 1 to 3,
The rotational speed detecting means is means for detecting rotational speeds of the output shaft and the drive shaft of the internal combustion engine,
The generator over-rotation estimating means determines that the rotation state of the planetary gear mechanism indicated by the detected rotation speed of the output shaft and the rotation speed of the drive shaft is suddenly decelerated to a value of 0. Then, it is means for estimating that the generator is in an over-rotation state when the rotation speed of the generator is within a preset range as a rotation state estimated to exceed the maximum rotation speed.
Hybrid car. An internal combustion engine, a generator capable of inputting / outputting power, an electric motor capable of inputting / outputting power to / from a drive shaft connected to drive wheels, a first rotating element, a second rotating element, and a third arranged in order in the alignment chart A planet having a rotating element, the first rotating element connected to the rotating shaft of the generator, the second rotating element connected to the output shaft of the internal combustion engine, and the third rotating element connected to the driving shaft. A control method for a hybrid vehicle comprising: a gear mechanism; a power storage means capable of exchanging electric power with the generator and the motor; and a braking means for applying a braking force to the vehicle based on a driver's operation,
Based on the rotational speed of at least two of the three shafts of the output shaft of the internal combustion engine, the rotating shaft of the generator, and the driving shaft, the rotational speed of the generator is caused to the generator by rapid deceleration of the driving wheel. When it is estimated that an overspeed state exceeding an allowable maximum number of rotations will occur and the braking force applied to the vehicle by the braking means is equal to or greater than a predetermined braking force, the rotational speed of the generator is The sum of the first condition where the rate of increase in the number of revolutions of the generator is 0 at the maximum number of revolutions and the power generated by the generator and the power consumed by the motor is A second condition that is within a range of input restriction set as a maximum allowable power when charging the power storage means based on the state, a torque that acts on the drive shaft by the power input and output from the generator, and the Power input / output from the motor Further, power is applied to the drive shaft within a range satisfying the third condition in which the sum of the torque acting on the drive shaft is less than the torque acting on the drive shaft by the braking force applied to the vehicle by the braking means. Controlling the internal combustion engine, the generator and the motor to be output;
Control method of hybrid vehicle.

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