JP2011126421A - Controller for vehicle driving system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably prevent overcharge or over-discharge of a battery that transfers power to/from first and second MGs (motor generators) in a hybrid vehicle. <P>SOLUTION: A discharge-side torque guard value is calculated from a discharge-side limited power (Wout-Pg) as a difference between the allowable discharge power Wout of the battery 21 and the generated power Pg of the first MG12, and the rotation speed of the second MG13. A charge-side torque guard value is calculated from a charge-side limited power (Win-Pg) as a difference between the allowable charge power Win of the battery 21 and the generated power Pg of the first MG12, and the rotation speed of the second MG13. In this case, hysteresis is applied to the characteristics of changing the rotation speed of the second MG13 to be used for calculating the discharge-side torque guard value, or to the characteristics of changing the rotation speed of the second MG13 to be used for calculating the charge-side torque guard value. Directions of applying the hysteresis are set according to the discharge-side restriction value (Wout-Pg) and the charge-side limited power (Win-Pg). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle drive system including a first motor generator connected to an internal combustion engine, a second motor generator connected to a drive shaft of the vehicle, and a battery that exchanges power with these motor generators. The invention relates to a control device.

  In recent years, the demand for hybrid vehicles has increased due to the social demand for low fuel consumption and low exhaust emissions. In a hybrid vehicle currently on the market, for example, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2001-329884), an engine (internal combustion engine) and a first used mainly as a generator are used. MG (motor generator) and a second MG that mainly drives the wheels, and connects the engine, the first MG, and the drive shaft of the wheels via a power split mechanism (for example, a planetary gear mechanism). There is a system in which the second MG and the drive shaft of the wheel are connected.

JP 2001-329884 A

  Thus, in the hybrid vehicle equipped with the first MG and the second MG, in order to prevent overdischarge or overcharge of the battery that exchanges power with the first MG and the second MG, the second MG The required power of MG (= requested torque × rotational speed) is determined by the discharge side limit amount (Wout−Pg) which is the difference between the discharge allowable power Wout of the battery and the generated power Pg of the first MG, and the charge allowable power of the battery It is necessary to limit within the range between the charge side limit (Win−Pg), which is the difference between Win and the generated power Pg of the first MG. Here, discharging is a positive value and charging is a negative value (the same applies hereinafter).

Therefore, the present inventors have studied the following system. In order to limit the required power of the second MG within a range between the discharge side limit (Wout-Pg) and the charge side limit (Win-Pg), the discharge side limit (Wout-Pg) The discharge side torque guard value Tm (out) for limiting the required torque of the second MG is calculated from the rotation speed Nm of the second MG, and the charge side limit amount (Win-Pg) and the rotation of the second MG are calculated. A charge side torque guard value Tm (in) for limiting the required torque of the second MG is calculated from the speed Nm.
Tm (out) = (Wout-Pg) / Nm
Tm (in) = (Win-Pg) / Nm

  At this time, in order to prevent deterioration of drivability due to fluctuation (vibration) of the rotation speed of the second MG, the second MG rotation speed (torque guard value calculation) used for calculating the torque guard value on the discharge side or the charge side. For the purpose of calculating the torque guard value, a hysteresis is given to the switching characteristic of the increase / decrease of the rotation speed for the second MG, and the rotation speed (peak value) having the larger absolute value when the rotation speed of the second MG fluctuates (vibrates). The rotation speed is recognized.

  As shown in FIG. 7A, during the operation of the vehicle, the discharge side limit (Wout-Pg) is often 0 or more and the charge side limit (Win-Pg) is smaller than 0. In this case, If the rotational speed (peak value) with the larger absolute value is recognized as the rotational speed for calculating the torque guard value when the rotational speed of the second MG fluctuates (vibrates), the torque guard value Both the discharge side torque guard value and the charge side torque guard value calculated from the rotation speed for calculation are the original torque limit ranges (the discharge side torque guard value and the charge side torque calculated from the actual rotation speed of the second MG). Therefore, overcharge and overdischarge of the battery can be prevented.

  However, depending on the driving conditions of the vehicle, the discharge side limit amount (Wout−Pg) may be smaller than 0, or the charge side limit amount (Win−Pg) may be 0 or more. For example, as shown in FIG. 7B, when the discharge side limit (Wout−Pg) is 0 or more and the charge side limit (Win−Pg) is 0 or more, the rotation speed of the second MG is If the rotational speed (peak value) with the larger absolute value when it fluctuates (vibrates) is recognized as the rotational speed for calculating the torque guard value, the charging-side torque calculated from the rotational speed for calculating the torque guard value Since the guard value is set outside the original torque limit range (overcharge side), the battery may be overcharged.

  Further, when the discharge side limit amount (Wout-Pg) is smaller than 0 and the charge side limit amount (Win-Pg) is smaller than 0 (not shown), the rotation speed of the second MG fluctuates (vibrates). ) Is recognized as the rotational speed for calculating the torque guard value, the discharge-side torque guard value calculated from the rotational speed for calculating the torque guard value is Since it is set outside the original torque limit range (overdischarge side), there is a possibility that overdischarge of the battery may occur.

  Therefore, the problem to be solved by the present invention is that in the hybrid vehicle equipped with the first MG and the second MG, the torque guard values on the discharge side and the charge side of the second MG can be set appropriately. An object of the present invention is to provide a control device for a vehicle drive system that can reliably prevent overcharge and overdischarge of a battery.

  In order to solve the above-described problem, an invention according to claim 1 is directed to a first motor generator (hereinafter referred to as “first MG”) connected to an internal combustion engine, and a first motor generator connected to a drive shaft of a vehicle. In a control device for a vehicle drive system including two motor generators (hereinafter referred to as “second MG”) and a battery that exchanges power with the first and second MGs, A discharge-side torque guard value for limiting the required torque of the second MG is calculated based on the difference from the generated power of the first MG (hereinafter referred to as “discharge-side limit amount”) and the rotation speed of the second MG. In addition, in order to limit the required torque of the second MG based on the difference between the allowable charging power of the battery and the generated power of the first MG (hereinafter referred to as “charge side limit amount”) and the rotation speed of the second MG. Calculate the charge side torque guard value of Torque guard value calculating means for calculating the rotation speed of the second MG used for calculating the discharge-side torque guard value (hereinafter referred to as “rotation speed for calculating the discharge-side torque guard value”). Hysteresis is added to the switching characteristic of increase / decrease, and the switching characteristic of increase / decrease of the rotation speed of the second MG used for calculation of the charge side torque guard value (hereinafter referred to as “rotation speed for calculation of charge side torque guard value”) is provided. The direction in which hysteresis is given is set according to the discharge side limit amount and the charge side limit amount.

  By doing so, the direction of the rotational speed hysteresis for calculating the discharge side torque guard value and the direction of the rotational speed hysteresis for calculating the charge side torque guard value are appropriately set according to the discharge side limit amount and the charge side limit amount. Therefore, the discharge-side torque guard value calculated from the rotation speed for calculating the discharge-side torque guard value or the discharge-side torque guard value calculated from the rotation speed for calculating the charge-side torque guard value can be changed to the original torque limit range. (The range between the discharge side torque guard value calculated from the actual rotation speed of the second MG and the charge side torque guard value) can be set inside. Thereby, the torque guard value on the discharge side and the charge side can be set appropriately, and overcharge and overdischarge of the battery can be reliably prevented.

  Specifically, as in claim 2, when the discharge-side limit amount is 0 or more and the charge-side limit amount is smaller than 0, the second MG is related to the rotational speed for calculating the discharge-side torque guard value. When the rotational speed fluctuates, the hysteresis direction is set so that the rotational speed with the larger absolute value is recognized as the rotational speed for calculating the discharge-side torque guard value. It is preferable to set the direction of hysteresis so that when the rotation speed of the second MG fluctuates, the rotation speed having the larger absolute value is recognized as the rotation speed for calculating the charge side torque guard value.

  In this way, as shown in FIG. 4, when the discharge side limit amount is 0 or more and the charge side limit amount is smaller than 0, the second rotational speed for calculating the discharge side torque guard value is When the rotational speed of the MG fluctuates (vibrates), the rotational speed (peak value) with the larger absolute value can be recognized as the rotational speed for calculating the discharge-side torque guard value. The discharge-side torque guard value calculated from the rotation speed can be set inside the original torque limit range. On the other hand, regarding the rotation speed for calculating the charge side torque guard value, when the rotation speed of the second MG fluctuates (vibrates), the rotation speed (peak value) having the larger absolute value is used for calculating the charge side torque guard value. The charge side torque guard value calculated from the rotation speed for calculating the charge side torque guard value can be set inside the original torque limit range.

  Further, as in claim 3, when the discharge side limit amount is 0 or more and the charge side limit amount is 0 or more, the rotation speed of the second MG varies with respect to the rotation speed for calculating the discharge side torque guard value. The direction of hysteresis is set so that the rotational speed with the larger absolute value is recognized as the rotational speed for calculating the discharge-side torque guard value, and the second MG is set for the rotational speed for calculating the charge-side torque guard value. It is preferable to set the direction of hysteresis so that the rotational speed with the smaller absolute value is recognized as the rotational speed for calculating the charge side torque guard value when the rotational speed of the motor changes.

  In this way, as shown in FIG. 5, when the discharge side limit amount is 0 or more and the charge side limit amount is 0 or more, the second MG is used for the rotational speed for calculating the discharge side torque guard value. When the rotation speed of the motor fluctuates (vibrates), the rotation speed (peak value) with the larger absolute value can be recognized as the rotation speed for calculating the discharge-side torque guard value. The discharge-side torque guard value calculated from the rotation speed can be set inside the original torque limit range. On the other hand, regarding the rotation speed for calculating the charge side torque guard value, when the rotation speed of the second MG fluctuates (vibrates), the rotation speed (peak value) having the smaller absolute value is used for calculating the charge side torque guard value. The charge side torque guard value calculated from the rotation speed for calculating the charge side torque guard value can be set inside the original torque limit range.

  Further, as in claim 4, when the discharge side limit amount is smaller than 0 and the charge side limit amount is smaller than 0, the rotational speed of the second MG is the rotational speed for calculating the discharge side torque guard value. The direction of hysteresis is set so that the rotational speed with a smaller absolute value is recognized as the rotational speed for calculating the discharge-side torque guard value when the value fluctuates. It is preferable to set the direction of hysteresis so that the rotational speed with the larger absolute value is recognized as the rotational speed for calculating the charge side torque guard value when the rotational speed of the MG varies.

  In this way, as shown in FIG. 6, when the discharge side limit amount is smaller than 0 and the charge side limit amount is smaller than 0, the second rotational speed for calculating the discharge side torque guard value is the second. When the rotational speed of the MG fluctuates (vibrates), the rotational speed (peak value) with the smaller absolute value can be recognized as the rotational speed for calculating the discharge-side torque guard value, and the discharge-side torque guard value is calculated. The discharge-side torque guard value calculated from the rotational speed for use can be set inside the original torque limit range. On the other hand, regarding the rotation speed for calculating the charge side torque guard value, when the rotation speed of the second MG fluctuates (vibrates), the rotation speed (peak value) having the larger absolute value is used for calculating the charge side torque guard value. The charge side torque guard value calculated from the rotation speed for calculating the charge side torque guard value can be set inside the original torque limit range.

FIG. 1 is a diagram showing a schematic configuration of a hybrid vehicle drive system in an embodiment of the present invention. FIG. 2 is a flowchart for explaining the processing flow of the torque guard value calculation routine. FIG. 3 is a flowchart for explaining the processing flow of the rotational speed calculation routine for calculating the torque guard value. FIG. 4 illustrates the direction of the rotational speed hysteresis for calculating the torque guard value when the discharge side limit (Wout−Pg) is 0 or more and the charge side limit (Win−Pg) is smaller than 0. FIG. FIG. 5 is a diagram for explaining the direction of the hysteresis of the rotational speed for calculating the torque guard value when the discharge side limit (Wout−Pg) is 0 or more and the charge side limit (Win−Pg) is 0 or more. It is. FIG. 6 illustrates the direction of the hysteresis of the rotational speed for calculating the torque guard value when the discharge side limit (Wout−Pg) is smaller than 0 and the charge side limit (Win−Pg) is smaller than 0. FIG. FIG. 7 is a diagram for explaining a problem when the direction of the hysteresis of the rotational speed for calculating the torque guard value is fixed.

Hereinafter, an embodiment embodying a mode for carrying out the present invention will be described.
First, the overall configuration of the hybrid vehicle drive system will be described with reference to FIG. An engine 11 that is an internal combustion engine, a first motor generator (hereinafter referred to as “first MG”) 12, and a second motor generator (hereinafter referred to as “second MG”) 13 are mounted. The second MG 13 serves as a power source for driving the wheels 14. The power of the crankshaft 15 of the engine 11 is divided into two systems by the power split mechanism 16.

  The power split mechanism 16 includes a planetary gear mechanism including a sun gear, a pinion gear, a ring gear (all not shown), and the like. A crankshaft 15 of the engine 11 is connected to the pinion gear via a carrier (not shown), and a rotation shaft of the first MG 12 mainly used as a generator is connected to the sun gear. Further, the ring gear is connected to a peller shaft 17 (drive shaft), and the power of the peller shaft 17 is transmitted to the wheels 14 via the differential gear mechanism 32, the axle 33, and the like. The rotating shaft of the second MG 13 is connected to the propeller shaft 17 via the reduction gear mechanism 18. Between the axle 33 and the wheel 14, a hydraulic brake device 34 that applies a braking force to the wheel 14 is provided.

  The first MG 12 and the second MG 13 are connected to the battery 21 via the power control unit 20. The power control unit 20 is provided with a first inverter 22 that drives the first MG 12 and a second inverter 23 that drives the second MG 13. Each MG 12, 13 has an inverter 22, 23. Via the battery 21, power is exchanged.

  A crank angle sensor 24 that outputs a pulse signal every time the crankshaft 15 rotates a predetermined crank angle is attached to the engine 11, and the crank angle and the engine rotation speed are detected based on the output signal of the crank angle sensor 24. . The first MG 12 is provided with a first rotor rotational position sensor 35 that detects the rotational position of the rotor, and the rotational speed of the first MG 12 is based on the output signal of the first rotor rotational position sensor 35. Is detected. Further, the second MG 13 is provided with a second rotor rotational position sensor 36 that detects the rotational position of the rotor, and the rotational speed of the second MG 13 is based on the output signal of the second rotor rotational position sensor 36. Is detected.

  The hybrid ECU 25 is a computer that comprehensively controls the entire hybrid vehicle, and detects an accelerator sensor 26 that detects an accelerator opening (amount of operation of an accelerator pedal), a shift switch 27 that detects an operation position of a shift lever, and a brake operation. The operation signal of the vehicle is detected by reading the output signals of various sensors and switches such as the brake switch 28 for performing the operation and the vehicle speed sensor 29 for detecting the vehicle speed. The hybrid ECU 25 includes an engine ECU 30 that controls the operation of the engine 11 and an MG-ECU 31 that controls the operations of the first and second MGs 12 and 13 by controlling the first and second inverters 22 and 23. Then, control signals and data signals are transmitted and received, and the ECUs 30, 31 control the operation of the engine 11, the first MG 12, and the second MG 13 according to the driving state of the vehicle.

  For example, at the time of starting or at a low load (a region where the fuel efficiency of the engine 11 is poor), the engine 11 is maintained in a stopped state, the second MG 13 is driven by the power of the battery 21, and the power of the second MG 13 is Only the motor travels by driving the wheel 14 and traveling.

  When starting the engine 11, the first MG 12 is driven by the electric power of the battery 21, and the power of the first MG 12 is transmitted to the crankshaft 15 of the engine 11 via the power split mechanism 16. The shaft 11 is rotationally driven to start the engine 11.

  During normal travel, the power of the crankshaft 15 of the engine 11 is divided into two systems, the first MG 12 side and the peller shaft 17 side, by the power split mechanism 16, and the peller shaft 17 is driven by the output of one of the wheels. 14 is driven, the first MG 12 is driven by the output of the other system, the first MG 12 is used to generate power, the second MG 13 is driven by the generated power, and the wheels 14 are also driven by the power of the second MG 13. To do. Further, at the time of rapid acceleration, in addition to the power generated by the first MG 12, the power of the battery 21 is also supplied to the second MG 13 to increase the driving amount of the second MG 13.

  During deceleration, the second MG 13 is driven by the power of the wheels 14 to operate the second MG 13 as a generator, whereby the kinetic energy of the vehicle is converted into electric power by the second MG 13 and recovered (charged). )

  Further, the hybrid ECU 25 calculates the required power of the vehicle based on the accelerator opening, the vehicle speed, the state of charge of the battery 21 and the like, and the required torque of the engine 11 and the first MG 12 so as to realize the required power of the vehicle. The required torque and the required torque of the second MG 13 are calculated. At this time, in order to prevent overdischarge and overcharge of the battery 21 that exchanges power with the first and second MGs 12 and 13, the second MG 13 Required power (= requested torque × rotational speed), the discharge side limit amount (Wout−Pg), which is the difference between the discharge allowable power Wout of the battery 21 and the generated power Pg of the first MG 12, and the charge allowable of the battery 21 It is necessary to limit within the range between the electric power Win and the charge side limit (Win−Pg) which is the difference between the electric power Win and the generated electric power Pg of the first MG 12. Here, discharging is a positive value and charging is a negative value (the same applies hereinafter).

Therefore, in the present embodiment, the hybrid ECU 25 controls the power demanded by the second MG 13 within the range between the discharge side limit (Wout−Pg) and the charge side limit (Win−Pg). The discharge side torque guard for limiting the required torque of the second MG 13 from the discharge side limit amount (Wout-Pg) and the rotation speed Nm of the second MG 13 by executing the routines of FIGS. While calculating the value Tm (out), the charging side torque guard value Tm (in) for limiting the required torque of the second MG 13 from the charging side limit (Win−Pg) and the rotation speed Nm of the second MG 13. Is calculated.
Tm (out) = (Wout-Pg) / Nm
Tm (in) = (Win-Pg) / Nm

  At this time, in this embodiment, the rotation of the second MG 13 used for calculating the discharge side torque guard value Tm (out) in order to prevent the drivability from deteriorating due to the fluctuation (vibration) of the rotation speed of the second MG 13. Hysteresis is added to the switching characteristics of increase / decrease of the speed (hereinafter referred to as “rotation speed for calculating the discharge side torque guard value”), and the rotation speed of the second MG 13 used for calculating the charge side torque guard value Tm (in) ( Hereinafter, hysteresis is given to the switching characteristic of increase / decrease of “rotation speed for calculating the charge side torque guard value”, and the direction in which those hysteresis is given is defined as the discharge side limit (Wout−Pg) and the charge side limit (Win). Set according to -Pg).

  Here, an example of a method of giving hysteresis to the switching characteristics of increase / decrease in the rotational speed for calculating the torque guard value on the discharge side or the charge side will be described.

  When hysteresis is provided in the decreasing direction of the absolute value of the rotational speed for calculating the torque guard value, the actual rotational speed of the second MG 13 (the rotational speed of the second MG 13 detected by the second rotor rotational position sensor 36). ) Is reversed from the increasing direction of the absolute value to the decreasing direction, and then the actual rotational speed of the second MG 13 is changed to a predetermined hysteresis interval (for example, when the changing direction of the actual rotational speed of the second MG 13 is reversed). The rotation speed for calculating the torque guard value is maintained at a constant value until the absolute value exceeds the interval from the value of (1) to a value that is smaller than the absolute value by a predetermined value). Otherwise, the second MG 13 The actual rotational speed (or the smoothed value of the actual rotational speed of the second MG 13) is used as the rotational speed for calculating the torque guard value.

  On the other hand, when a hysteresis is provided in the increasing direction of the absolute value of the rotational speed for calculating the torque guard value, when the change direction of the actual rotational speed of the second MG 13 is reversed from the decreasing direction of the absolute value to the increasing direction. Thereafter, the actual rotational speed of the second MG 13 is a predetermined hysteresis section (for example, a section from the value at the time of reversing the changing direction of the actual rotational speed of the second MG 13 to a value whose absolute value is larger than that by a predetermined value). ) Is maintained at a constant value without changing the rotational speed for calculating the torque guard value until it exceeds (), otherwise the actual rotational speed of the second MG 13 (or the annealing value of the actual rotational speed of the second MG 13) is maintained. ) Is adopted as the rotational speed for calculating the torque guard value.

  In this embodiment, the direction in which the hysteresis is given is set as follows according to the discharge side limit (Wout-Pg) and the charge side limit (Win-Pg).

[First method]
As shown in FIG. 4, when the discharge side limit (Wout-Pg) is 0 or more and the charge side limit (Win-Pg) is smaller than 0, the direction of hysteresis is set by the first method. . In this case, with respect to the rotational speed Nm (out) for calculating the discharge-side torque guard value, the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the absolute value decreasing direction. The hysteresis direction is set so that the rotational speed (peak value) on the side with a larger absolute value is sometimes recognized as the rotational speed Nm (out) for calculating the discharge side torque guard value. As a result, when the rotational speed of the second MG 13 fluctuates within the hysteresis interval, the rotational speed having the larger absolute value can be recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. The discharge-side torque guard value Tm (out) calculated from the rotation speed Nm (out) for calculating the discharge-side torque guard value is set to the original torque limit range (discharge-side torque guard calculated from the actual rotation speed of the second MG 13). Value and the charging side torque guard value).

  On the other hand, with respect to the rotational speed Nm (in) for calculating the charge side torque guard value, when the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the decreasing direction of the absolute value. The direction of hysteresis is set so that the rotation speed (peak value) with the larger absolute value is recognized as the rotation speed Nm (in) for calculating the charge side torque guard value. As a result, when the rotational speed of the second MG 13 fluctuates within the hysteresis interval, the rotational speed having the larger absolute value can be recognized as the rotational speed Nm (in) for calculating the charge side torque guard value. The charging side torque guard value Tm (in) calculated from the rotation speed Nm (in) for calculating the charging side torque guard value can be set inside the original torque limit range.

[Second method]
As shown in FIG. 5, when the discharge side limit (Wout-Pg) is 0 or more and the charge side limit (Win-Pg) is 0 or more, the direction of hysteresis is set by the second method. In this case, with respect to the rotational speed Nm (out) for calculating the discharge-side torque guard value, the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the absolute value decreasing direction. The hysteresis direction is set so that the rotational speed (peak value) on the side with a larger absolute value is sometimes recognized as the rotational speed Nm (out) for calculating the discharge side torque guard value. As a result, when the rotational speed of the second MG 13 fluctuates within the hysteresis interval, the rotational speed having the larger absolute value can be recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. The discharge-side torque guard value Tm (out) calculated from the rotational speed Nm (out) for calculating the discharge-side torque guard value can be set inside the original torque limit range.

  On the other hand, regarding the rotational speed Nm (in) for calculating the charging side torque guard value, when the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the increasing direction of the absolute value. The direction of hysteresis is set so that the rotational speed (peak value) with the smaller absolute value is recognized as the rotational speed Nm (in) for calculating the charge side torque guard value. As a result, when the rotational speed of the second MG 13 fluctuates within the hysteresis interval, the rotational speed having a smaller absolute value can be recognized as the rotational speed Nm (in) for calculating the charge side torque guard value. The charging side torque guard value Tm (in) calculated from the rotation speed Nm (in) for calculating the charging side torque guard value can be set inside the original torque limit range.

[Third method]
As shown in FIG. 6, when the discharge side limit amount (Wout−Pg) is smaller than 0 and the charge side limit amount (Win−Pg) is smaller than 0 (however, Wout ≧ Win), the third Set the direction of hysteresis by the method. In this case, with respect to the rotational speed Nm (out) for calculating the discharge side torque guard value, the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the increasing direction of the absolute value. The direction of hysteresis is set so that the rotational speed (peak value) with the smaller absolute value is sometimes recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. As a result, when the rotational speed of the second MG 13 fluctuates within the hysteresis interval, the rotational speed with the smaller absolute value can be recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. The discharge side torque guard value Tm (out) calculated from the rotational speed Nm (out) for calculating the discharge side torque guard value can be set inside the original torque limit range.

  On the other hand, regarding the rotational speed Nm (in) for calculating the charge side torque guard value, when the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis section by providing hysteresis in the decreasing direction of the absolute value. The direction of hysteresis is set so that the rotation speed (peak value) with the larger absolute value is recognized as the rotation speed Nm (in) for calculating the charge side torque guard value. As a result, when the rotational speed of the second MG 13 fluctuates within the hysteresis interval, the rotational speed having the larger absolute value can be recognized as the rotational speed Nm (in) for calculating the charge side torque guard value. The charging side torque guard value Tm (in) calculated from the rotation speed Nm (in) for calculating the charging side torque guard value can be set inside the original torque limit range.

  Hereinafter, the processing content of each routine of FIG.2 and FIG.3 which hybrid ECU25 performs is demonstrated. Note that the processing of these routines may be executed by the engine ECU 30 or the MG-ECU 31.

[Torque guard value calculation routine]
The torque guard value calculation routine shown in FIG. 2 is repeatedly executed at a predetermined period while the hybrid ECU 25 is powered on, and serves as a torque guard value calculation means in the claims. When this routine is started, first, in step 101, the discharge allowable power Wout and the charge allowable power of the battery 21 are determined based on the temperature of the battery 21 and the state of charge SOC (= remaining capacity / full charge capacity) of the battery 21. Win is calculated.

  Thereafter, the process proceeds to step 102, and after calculating a discharge side limit amount (Wout−Pg) that is a difference between the discharge allowable power Wout of the battery 21 and the generated power Pg of the first MG 12, the process proceeds to step 103 and the battery 21 The charge side limit amount (Win−Pg), which is the difference between the charge allowable power Win of the first MG 12 and the generated power Pg of the first MG 12 is calculated.

  Thereafter, the process proceeds to step 104, and a rotation speed calculation routine for calculating the torque guard value shown in FIG. 3 described later is executed to calculate the rotation speed Nm (out) for calculating the discharge side torque guard value and the charge side torque guard value. Rotational speed Nm (in) is calculated.

Thereafter, the routine proceeds to step 105, where the required torque of the second MG 13 is limited by the following equation using the discharge side limit amount (Wout−Pg) and the rotation speed Nm (out) for calculating the discharge side torque guard value. The discharge side torque guard value Tm (out) is calculated.
Tm (out) = (Wout−Pg) / Nm (out)

Thereafter, the routine proceeds to step 106, where the required torque of the second MG 13 is limited by the following equation using the charging side limit amount (Win−Pg) and the rotation speed Nm (in) for calculating the charging side torque guard value. The charging side torque guard value Tm (in) is calculated.
Tm (in) = (Win-Pg) / Nm (in)

[Rotational speed calculation routine for torque guard value calculation]
The rotation speed calculation routine for calculating the torque guard value shown in FIG. 3 is a subroutine executed in step 104 of the torque guard value calculation routine of FIG. When this routine is started, first, at step 201, it is determined whether or not the discharge side limit amount (Wout−Pg) is 0 or more, and the discharge side limit amount (Wout−Pg) is 0 or more. If it is determined, the routine proceeds to step 202, where it is determined whether or not the charging side limit amount (Win-Pg) is smaller than zero.

  When it is determined in step 201 that the discharge side limit (Wout−Pg) is 0 or more, and in step 202, it is determined that the charge side limit (Win−Pg) is smaller than 0, Proceeding to step 203, the direction of hysteresis is set by the first method.

  In the first method, as shown in FIG. 4, the rotational speed Nm (out) for calculating the discharge-side torque guard value is provided with hysteresis in the decreasing direction of the absolute value, thereby rotating the second MG 13. Sets the direction of hysteresis so that when the speed fluctuates (vibrates) within the hysteresis interval, the rotational speed (peak value) with the larger absolute value is recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. To do. On the other hand, with respect to the rotational speed Nm (in) for calculating the charge side torque guard value, when the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the decreasing direction of the absolute value. The direction of hysteresis is set so that the rotation speed (peak value) with the larger absolute value is recognized as the rotation speed Nm (in) for calculating the charge side torque guard value.

  Further, when it is determined in step 201 that the discharge side limit (Wout−Pg) is 0 or more, and in step 202, it is determined that the charge side limit (Win−Pg) is 0 or more. Advances to step 204 to set the direction of hysteresis in the second method.

  In the second method, as shown in FIG. 5, the rotational speed Nm (out) for calculating the discharge side torque guard value is provided with hysteresis in the decreasing direction of the absolute value, thereby rotating the second MG 13. Sets the direction of hysteresis so that when the speed fluctuates (vibrates) within the hysteresis interval, the rotational speed (peak value) with the larger absolute value is recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. To do. On the other hand, regarding the rotational speed Nm (in) for calculating the charging side torque guard value, when the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis interval by providing hysteresis in the increasing direction of the absolute value. The direction of hysteresis is set so that the rotational speed (peak value) with the smaller absolute value is recognized as the rotational speed Nm (in) for calculating the charge side torque guard value.

  When it is determined in step 201 that the discharge side limit (Wout−Pg) is smaller than 0, the discharge side limit (Wout−Pg) is smaller than 0 and the charge side limit (Win−) Pg) is smaller than 0 (however, Wout.gtoreq.Win), the process proceeds to step 205, and the direction of hysteresis is set by the third method.

  In this third method, as shown in FIG. 6, the rotational speed Nm (out) for calculating the discharge-side torque guard value is provided with hysteresis in the increasing direction of the absolute value, thereby rotating the second MG 13. Sets the direction of hysteresis so that when the speed fluctuates (vibrates) within the hysteresis interval, the rotational speed (peak value) with the smaller absolute value is recognized as the rotational speed Nm (out) for calculating the discharge-side torque guard value. To do. On the other hand, regarding the rotational speed Nm (in) for calculating the charge side torque guard value, when the rotational speed of the second MG 13 fluctuates (vibrates) within the hysteresis section by providing hysteresis in the decreasing direction of the absolute value. The direction of hysteresis is set so that the rotation speed (peak value) with the larger absolute value is recognized as the rotation speed Nm (in) for calculating the charge side torque guard value.

  Thereafter, the process proceeds to step 206, reflecting the hysteresis characteristic set in any of the above steps 203 to 205, and based on the actual rotational speed of the second MG 13, the rotational speed Nm (out ) Is calculated, the process proceeds to step 207 to reflect the hysteresis characteristic set in any of the above steps 203 to 205, and based on the actual rotational speed of the second MG 13, the rotational speed for calculating the charge side torque guard value Nm (in) is calculated.

  In the present embodiment described above, hysteresis is added to the switching characteristics for increasing / decreasing the rotational speed Nm (out) for calculating the discharge side torque guard value and the switching characteristics for increasing / decreasing the rotational speed Nm (in) for calculating the charge side torque guard value. The direction in which the hysteresis is given is set according to the discharge side limit amount (Wout−Pg) and the charge side limit amount (Win−Pg), so that the discharge side limit amount (Wout−Pg) and Depending on the charge side limit (Win-Pg), the hysteresis direction of the rotational speed Nm (out) for calculating the discharge side torque guard value and the hysteresis direction of the rotational speed Nm (in) for calculating the charge side torque guard value It is possible to switch appropriately, from the discharge side torque guard value Tm (out) calculated from the rotation speed Nm (out) for calculating the discharge side torque guard value and the rotation speed Nm (in) for calculating the charge side torque guard value. Calculated discharge side torque guard Tm and (in), it is possible to set the inside of the original torque limit range (range between the second charging side torque guard value and the discharge-side torque guard value calculated from the actual rotational speed of MG132). Thereby, the discharge side torque guard value Tm (out) and the charge side torque guard value Tm (in) can be set appropriately, and the overcharge and overdischarge of the battery 21 can be reliably prevented.

  In the above embodiment, the present invention is applied to a hybrid vehicle in which the engine, the first MG, and the drive shaft of the wheel are connected via a power split mechanism and the second MG and the drive shaft of the wheel are connected. Although applied, the present invention is not limited to this type of hybrid vehicle, and any other type of hybrid vehicle can be used as long as it has a first MG connected to the engine and a second MG connected to the drive shaft of the vehicle. The present invention may be applied to a car.

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 12 ... 1st MG, 13 ... 2nd MG, 14 ... Wheel, 16 ... Power split mechanism, 17 ... Peller shaft (drive shaft), 21 ... Battery, 22 ... First Inverter, 23 ... second inverter, 25 ... hybrid ECU (torque guard value calculation means), 30 ... engine ECU, 31 ... MG-ECU

Claims (4)

A first motor generator (hereinafter referred to as “first MG”) connected to the internal combustion engine and a second motor generator (hereinafter referred to as “second MG”) connected to the drive shaft of the vehicle. And a control device for a vehicle drive system comprising the first and second MGs and a battery for transferring power.
The required torque of the second MG is limited based on the difference between the discharge allowable power of the battery and the generated power of the first MG (hereinafter referred to as “discharge-side limit amount”) and the rotation speed of the second MG. And calculating a discharge side torque guard value for performing the charging, a difference between the charge allowable power of the battery and the generated power of the first MG (hereinafter referred to as “charge side limit amount”), and the rotation speed of the second MG. Torque guard value calculating means for calculating a charging side torque guard value for limiting the required torque of the second MG based on
The torque guard value calculating means has hysteresis in a switching characteristic of increase / decrease in the rotation speed of the second MG used for calculation of the discharge side torque guard value (hereinafter referred to as “rotation speed for calculating discharge side torque guard value”). And a switching characteristic of increase / decrease in the rotation speed of the second MG used for calculation of the charge side torque guard value (hereinafter referred to as “rotation speed for calculation of charge side torque guard value”) is provided with hysteresis, and the discharge side A control device for a vehicle drive system, wherein a direction in which the hysteresis is provided is set according to a limit amount and the charge side limit amount.   The torque guard value calculating means determines the second MG rotation speed for calculating the discharge side torque guard value when the discharge side limit amount is 0 or more and the charge side limit amount is less than 0. The direction of the hysteresis is set so as to recognize the rotation speed having the larger absolute value as the rotation speed for calculating the discharge side torque guard value when the rotation speed fluctuates, and the rotation for calculating the charge side torque guard value Regarding the speed, means for setting the direction of the hysteresis so as to recognize a rotational speed having a larger absolute value as a rotational speed for calculating the charge side torque guard value when the rotational speed of the second MG fluctuates. The control device for a vehicle drive system according to claim 1, comprising:   The torque guard value calculating means rotates the second MG with respect to the rotational speed for calculating the discharge side torque guard value when the discharge side limit amount is 0 or more and the charge side limit amount is 0 or more. When the speed fluctuates, the hysteresis direction is set so as to recognize the rotation speed having the larger absolute value as the rotation speed for calculating the discharge side torque guard value, and the rotation speed for calculating the charge side torque guard value. With respect to the second MG, there is provided means for setting the direction of the hysteresis so as to recognize the rotational speed having a smaller absolute value as the rotational speed for calculating the charging side torque guard value when the rotational speed of the second MG fluctuates. The control device for a vehicle drive system according to claim 1 or 2.   The torque guard value calculation means, when the discharge side limit amount is smaller than 0 and the charge side limit amount is smaller than 0, regarding the rotation speed for calculating the discharge side torque guard value, the second MG. The direction of the hysteresis is set so that the rotational speed with a smaller absolute value is recognized as the rotational speed for calculating the discharge side torque guard value when the rotational speed of With respect to the rotational speed, means for setting the direction of the hysteresis so as to recognize the rotational speed having the larger absolute value as the rotational speed for calculating the charging side torque guard value when the rotational speed of the second MG fluctuates. The control device for a vehicle drive system according to any one of claims 1 to 3, further comprising:

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