JP6237432B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle, and more specifically, three rotary elements are connected to an engine, a first motor, a drive shaft coupled to an axle, an output shaft of the engine, and a rotary shaft of the first motor. The present invention relates to a control device for a hybrid vehicle, comprising: a planetary gear; a second motor having a rotation shaft connected to a drive shaft; and a battery that exchanges power with the first motor and the second motor.

  Conventionally, this type of hybrid vehicle control device includes an engine, a first motor, a drive shaft coupled to the axle, a planetary gear in which a ring gear, a carrier, and a sun gear are connected to the engine and the first motor, and a drive In a hybrid vehicle control device including a second motor connected to a shaft and a battery that exchanges electric power with the first motor and the second motor, when the shift position is the reverse travel position, It has been proposed to control the engine by setting the engine operating point (target speed and target torque) using the engine command power and the operation line in which the target speed becomes larger and the target torque becomes smaller than the operating line. (For example, refer to Patent Document 1). In this control device, when the shift position is in the reverse travel position, the engine is operated at the operating point on the lower side of the higher rotation speed and lower torque than in the forward travel position in this way. The forward torque acting on the drive shaft is reduced to prevent the reverse drive torque from being reduced.

JP 2010-163090 A

  In the above-described control device, when the shift position is the reverse travel position, the engine is operated at the operating point on the high speed and low torque side compared to the forward travel position, so the engine and the first motor have a high rotational speed. Cheap. For this reason, in the range where the upper limit rotational speed of the first motor is lower than the rotational speed for over-rotation determination determined from the design requirements of the first motor, the rotation speed is higher at the reverse travel position than at the forward travel position. It is considered to be a number. Further, when the rotation speed of the first motor approaches the upper limit rotation speed, it is necessary to perform control for suppressing the rotation speed from exceeding the upper limit rotation speed. This control is uniformly performed regardless of the shift position. If the reverse drive position is set, the difference between the upper limit rotational speed and the overspeed determination rotational speed is smaller in the reverse travel position than in the forward travel position, so the rotational speed of the first motor is the overspeed determination rotational speed. (Easy to over-rotate). If the first motor is over-rotated, there is a possibility that an abnormality caused by the first motor may occur. Therefore, it is required to prevent the first motor from over-rotating.

  The control device for a hybrid vehicle of the present invention is mainly intended to prevent the first motor from over-rotating during reverse travel.

  The control device for a hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The control device for a hybrid vehicle of the present invention includes:
An engine, a first motor, a drive shaft connected to an axle, a planetary gear in which three rotation elements are connected to an output shaft of the engine and a rotation shaft of the first motor, and a rotation shaft connected to the drive shaft A control device for a hybrid vehicle, comprising: the second motor that has been made; and a battery that exchanges electric power with the first motor and the second motor,
The upper limit rotational speed of the first motor is set to be lower than the rotational speed for over-rotation determination of the first motor and higher than the forward traveling position when the shift position is the backward traveling position,
When the rotational speed of the first motor approaches the upper limit rotational speed, the first motor is controlled to decrease the rotational speed of the first motor with respect to the upper limit rotational speed;
The amount of decrease is greater when the shift position is the reverse drive position and when the forward drive position is
It is characterized by that.

  In the hybrid vehicle control device of the present invention, the first motor is set within a range lower than the rotational speed for over-rotation determination of the first motor and higher when the shift position is the reverse travel position than at the forward travel position. Set to the maximum motor speed. Then, when the rotation speed of the first motor approaches the upper limit rotation speed, the first motor is controlled so as to decrease the rotation speed of the first motor relative to the upper limit rotation speed. The reverse travel position is larger than the forward travel position. When the shift position is the reverse travel position, the difference between the upper limit rotational speed and the overspeed determination rotational speed is smaller than in the forward travel position. By performing such control, the first motor rotational speed is the upper limit rotational speed. It is possible to prevent the number from excessively exceeding the number and reaching the overspeed determination speed (becomes overspeed). As a result, it is possible to suppress the occurrence of an abnormality due to the excessive rotation of the first motor.

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 alignment chart which shows the relationship of the rotation speed in each rotation element of the planetary gear 30 at the time of reverse drive in HV driving mode. It is explanatory drawing which shows an example of the relationship between the value (Nm1max-Nm1) obtained by subtracting the rotation speed Nm1 from the upper limit rotation speed Nm1max (Nm1max (D) or Nm1max (R)) of the motor MG1 and the upper limit torque Tm1max of the motor MG1. is there.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 including a control device for a hybrid vehicle as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline, light oil, or the like as fuel, and an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 that drives and controls the engine 22. A planetary gear 30 in which a carrier is connected to the crankshaft 26 of the engine 22 and a ring gear is connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a synchronous generator motor, for example. A motor MG1 having a rotor (rotating shaft) connected to the sun gear of the planetary gear 30, a motor MG2 configured as a synchronous generator motor and having a rotor (rotating shaft) connected to the drive shaft 36, and motors MG1, MG2 Inverters 41 and 42 for driving, and inverters 41 and 4 And a motor electronic control unit (hereinafter referred to as “motor ECU”) 40 for driving and controlling the motors MG1 and MG2 by switching control of a switching element (not shown), and inverters 41 and 42 configured as, for example, a lithium ion secondary battery. A battery 50 that exchanges electric power with the motors MG1 and MG2, via a battery electronic control unit (hereinafter referred to as “battery ECU”) 52 that manages the battery 50, and a hybrid electronic control unit (hereinafter referred to as “battery ECU”). , “HVECU”) 70. The “hybrid vehicle control device” of the present invention corresponds to the HVECU 70, the engine ECU 24, and the motor ECU 40.

  The engine ECU 24 receives signals from various sensors necessary to control the operation of the engine 22, and the engine ECU 24 outputs various control signals for controlling the operation of the engine 22. The engine ECU 24 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 of the engine 22.

  The motor ECU 40 receives signals from various sensors necessary to drive and control the motors MG1 and MG2, and the motor ECU 40 outputs switching control signals to switching elements (not shown) of the inverters 41 and 42. Has been. The motor ECU 40 determines the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensor that detects the rotational positions of the rotors of the motors MG1, MG2. Arithmetic.

  Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52. The battery ECU 52 manages the battery 50 based on the integrated value of the charge / discharge current Ib of the battery 50 detected by a current sensor (not shown), and the ratio of the capacity of power that can be discharged from the battery 50 at that time to the total capacity Is calculated.

  The HVECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator opening from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Acc, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input. The HVECU 70 is communicably connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. In the hybrid vehicle 20 of the embodiment, the operation position of the shift lever 81 (shift position SP detected by the shift position sensor 82) includes a parking position (P position) used during parking, and a reverse position (R for reverse travel). Position), neutral position (N position), forward drive position (D position), etc.

  The hybrid vehicle 20 of the embodiment thus configured travels in a hybrid travel mode (HV travel mode) that travels with the operation of the engine 22 or an electric travel mode (EV travel mode) that travels with the engine 22 stopped. To do.

  During travel in the HV travel mode, the HVECU 70 sets the required torque Tr * required for travel based on the accelerator opening Acc and the vehicle speed V, and sets the rotational speed Nr ( For example, the traveling power Pdrv * required for traveling is calculated by multiplying the rotational speed Nm2 of the motor MG2 and the rotational speed obtained by multiplying the vehicle speed V by a conversion factor), and the battery 50 is calculated from the calculated traveling power Pdrv *. The required power Pe * required for the vehicle is set by subtracting the charge / discharge required power Pb * based on the storage ratio SOC.

  Then, the target rotational speed Ne * and the target torque Te * of the engine 22 are set based on the shift position SP and the required power Pe *. In the embodiment, when the shift position SP is the D position, the rotational speed and torque (hereinafter, this operating point) based on the required power Pe * and an operation line (for example, an optimum fuel efficiency operation line) for operating the engine 22 efficiently. The fuel efficiency operating point) is set to the target rotational speed Ne * and the target torque Te * of the engine 22. This is for operating the engine 22 efficiently. Further, when the shift position SP is in the R position, the rotational speed and torque at the high rotational speed and low torque side from the fuel efficiency operating point (hereinafter, this operating point is referred to as “high rotational speed operating point”) based on the required power Pe *. The target rotational speed Ne * and the target torque Te * of the engine 22 are set. This suppresses an excessive decrease in the storage ratio SOC of the battery 50 and torque applied to the drive shaft 36 from the engine 22 through the planetary gear 30 (torque in the direction opposite to the reverse travel torque required by the vehicle). This is to reduce the engine torque (hereinafter, referred to as “engine direct torque”) (for example, to ensure climbing performance during climbing in reverse travel).

  Next, using the target torque Te * of the engine 22 and the gear ratio ρ of the planetary gear 30 (the number of teeth of the sun gear / the number of teeth of the ring gear), the target rotational speed Ne * of the engine 22 and the rotational speed Ne, the following equation (1) To set a temporary torque Tm1tmp as a temporary value of the torque command Tm1 * of the motor MG1, and set the torque command Tm1 * of the motor MG1 by limiting the set temporary torque Tm1tmp with upper and lower limit torques Tm1max and Tm1min. Here, Expression (1) is a relational expression in the rotational speed feedback control for rotating the engine 22 at the target rotational speed Ne *. In Expression (1), “k1” in the second term on the right side is a proportional term. It is a gain, and “k2” in the third term on the right side is the gain of the integral term. Then, as shown in the equation (2), the torque (−Tm1 * / ρ) output from the motor MG1 and acting on the drive shaft 36 via the planetary gear 30 is subtracted from the required torque Tr * to reduce the torque command Tm2 of the motor MG2. A temporary torque Tm2tmp is set as a temporary value of *, and the set temporary torque Tm2tmp is limited by upper and lower limit torques Tm2max and Tm2min to set a torque command Tm2 * of the motor MG2. In the embodiment, the lower limit torque Tm1min of the motor MG1 is set to the negative rated torque (−Tm1lim), and the upper and lower limit torques Tm2max and Tm2min of the motor MG2 are the positive and negative rated torques Tm2lim, -Set Tm2lim. Although the upper limit torque Tm1max of the motor MG1 will be described in detail later, basically, the rated torque Tm1lim on the positive side is set, and the rotation speed Nm1 of the motor MG1 approaches the upper limit rotation speed Nm1max according to the shift position SP. In some cases, a torque smaller than the rated torque Tm1lim is set.

Tm1tmp = -ρ ・ Te * / (1 + ρ) + k1 (Ne * -Ne) + k2∫ (Ne * -Ne) dt (1)
Tm2tmp = Tr * + Tm1 * / ρ (2)

  Then, the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * controls the intake air amount and the fuel injection control of the engine 22 so that the engine 22 is operated based on the target rotational speed Ne * and the target torque Te *. Perform ignition control. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  During traveling in the HV traveling mode, the storage ratio SOC of the battery 50 is larger than a threshold value Sch (for example, 40%) that requires forced charging of the battery 50, and the required power Pe * is a stop threshold value Pstop (for example, several kW). When it reaches less than, for example, it is determined that the stop condition of the engine 22 has been established, the operation of the engine 22 is stopped, and the travel is shifted to the EV travel mode.

  During travel in the EV travel mode, the HVECU 70 sets the required torque Tr * based on the accelerator opening Acc and the vehicle speed V, sets the value 0 to the temporary torque Tm1tmp of the motor MG1, and increases the set temporary torque Tm1tmp. The torque command Tm1 * of the motor MG1 is set by limiting with the lower limit torques Tm1max and Tm1min, the temporary torque Tm2tmp of the motor MG2 is set by the above equation (2), and the set temporary torque Tm2tmp is set to the upper and lower limit torques Tm2max and Tm2min The torque command Tm2 * of the motor MG2 is set in a limited manner, and the set torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40. Then, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * performs switching control of the switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *.

  When traveling in the EV traveling mode, the required power Pe * calculated when the storage ratio SOC of the battery 50 is equal to or less than the threshold Sch or when traveling in the hybrid traveling mode is larger than the stop threshold Pstop by a margin. When it reaches the threshold value Pstart or more, it is determined that the start condition of the engine 22 is satisfied, and the engine 22 is started to shift to travel in the HV travel mode.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when setting the torque command Tm1 * of the motor MG1 during traveling in the HV traveling mode will be described. FIG. 2 is an explanatory diagram showing an example of a collinear diagram showing the relationship between the rotational speeds of the rotating elements of the planetary gear 30 during reverse travel in the HV travel mode. In the figure, the left S-axis indicates the rotational speed of the sun gear, which is the rotational speed Nm1 of the motor MG1, the C-axis indicates the rotational speed of the carrier, which is the rotational speed Ne of the engine 22, and the R-axis indicates the rotational speed Nm2 of the motor MG2. The rotation speed Nr of the ring gear is shown. Further, in the figure, “Nm1os” indicates an overspeed determination rotational speed (for example, 13300 rpm, 13500 rpm, 13700 rpm, etc.) for determining the overspeed of the motor MG1, and “Nm1max (D)” indicates the shift position SP. Indicates an upper limit rotational speed (for example, 11800 rpm, 12000 rpm, 12200 rpm, etc.) when D is in the D position, and “Nm1max (R)” indicates an upper limit rotational speed (for example, 12300 rpm, 12,500 rpm, 12700 rpm) when the shift position SP is in the R position. Etc.) The reason why the upper limit rotational speed Nm1max (R) is made larger than the upper limit rotational speed Nm1max (D) is as follows. In the embodiment, as described above, when the shift position SP is in the R position, an excessive decrease in the storage ratio SOC of the battery 50 is suppressed and the engine direct torque is reduced (for example, climbing performance during climbing in reverse travel) In order to ensure the above, the high speed operating point is set as the target operating point of the engine 22. For this reason, the rotational speed Nm1 of the motor MG1 tends to be larger than when the shift position SP is the D position. On the other hand, when traveling backward in the HV traveling mode, the vehicle travels over a long distance (long time) on the uphill road (the required power Pe * is continuously increased over a long time, thereby increasing the rotational speed Ne of the engine 22 and the motor MG1. , Nm1 is large for a long time). Based on these, in the embodiment, the upper limit rotational speed Nm1max (R) is set to be larger than the upper limit rotational speed Nm1max (D). Accordingly, when the vehicle travels backward in the HV traveling mode, the engine speed of the engine 22 and the motor MG1 is allowed to increase, so that a decrease in output power of the engine 22 can be suppressed. Therefore, it is possible to suppress an excessive decrease in the storage ratio SOC of the vehicle, and to further improve the climbing performance (longer the climbable distance).

  FIG. 3 shows an example of the relationship between the value (Nm1max−Nm1) obtained by subtracting the rotation speed Nm1 from the upper limit rotation speed Nm1max (Nm1max (D) or Nm1max (R)) of the motor MG1 and the upper limit torque Tm1max of the motor MG1. It is explanatory drawing shown. As shown in the figure, the upper limit torque Tm1max is a positive value of the motor MG1 in the region where the value (Nm1max−Nm1) is equal to or greater than a predetermined value α1 (for example, 400 rpm, 500 rpm, 600 rpm, etc.) The rated torque Tm1lim on the side is set. In the region where the value (Nm1max−Nm1) is less than the predetermined value α1, the upper limit torque Tm1max tends to be smaller as the value (Nm1max−Nm1) is smaller regardless of whether the shift position SP is the D position or the R position. When the position SP is the R position, it is set to be smaller than when the position SP is the D position. In the figure, “αd” and “αr” are values (Nm1max−Nm1) when the upper limit torque Tm1max is 0 when the shift position SP is the D position and the R position, respectively. “Is 70 rpm, 100 rpm, 130 rpm, etc., and“ αr ”is 170 rpm, 200 rpm, 230 rpm, etc. In the embodiment, as described above, the temporary torque Tm1tmp is limited by the upper limit torque Tm1max and the lower limit torque Tm1min to which the negative rated torque (−Tm1lim) is set, and the torque command Tm1 * of the motor MG1 is set. By setting the upper limit torque Tm1max in the tendency of FIG. 3, the torque command Tm1 * of the motor MG1 is such that when the shift position SP is the D position and the R position, the rotational speed Nm1 of the motor MG1 is a value (Nm1max When higher than (d) −αd), (Nm1max (r) −αr), the upper limit torque Tm1max is limited to a negative value. When the rotational speed Nm1 of the motor MG1 approaches the upper limit rotational speeds Nm1max (D) and Nm1max (R) according to the shift position SP (when the shift position SP is in the D position, from the value (Nm1max (d) −αd) When the shift position SP is in the R position, the rotation speed Nm1 of the motor MG1 is set to a value higher than the upper limit rotation speed Nm1max when the shift position SP is in the R position and higher than in the value (Nm1max (r) −αr). Thus, a torque that greatly decreases (a large torque on the negative side) is output from the motor MG1. The upper limit rotational speed Nm1max (R) is larger than the upper limit rotational speed Nm1max (D), that is, close to the overspeed determination rotational speed Nm1os. Thus, by controlling the motor MG1, the rotational speed Nm1 of the motor MG1 is increased to the upper limit rotational speed. It is possible to suppress the number Nm1max (R) from being greatly exceeded and reaching the overspeed determination speed Nm1os (becomes overspeed). As a result, it is possible to suppress the occurrence of an abnormality due to the excessive rotation of the motor MG1.

  According to the control apparatus for hybrid vehicle 20 of the embodiment described above, the motor MG1 has a motor so that the shift position SP is higher than the D position when the shift position SP is the R position within the range below the overspeed determination rotational speed Nm1os. In setting the upper limit rotational speed Nm1max of MG1, when the rotational speed Nm1 of the motor MG1 approaches the upper limit rotational speed Nm1max, the motor MG1 is controlled so as to decrease the rotational speed Nm1 of the motor MG1 with respect to the upper limit rotational speed Nm1max. Since the decrease amount is larger when the shift position SP is the R position than when the shift position SP is the D position, the rotation speed Nm1 of the motor MG1 is set to the upper limit rotation speed Nm1max when the shift position SP is the R position. Greatly exceeded the speed Nm1os for overspeed determination To from (a overspeed) can be suppressed.

  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 “engine”, the motor MG1 corresponds to the “first motor”, the planetary gear 30 corresponds to the “planetary gear”, the motor MG2 corresponds to the “second motor”, and the battery 50 Corresponds to the “battery”, and the HVECU 70, the engine ECU 24, and the motor ECU 40 correspond to the “control device”.

  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. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. 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.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

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

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 40 motor electronic control unit (motor ECU), 41, 42 Inverter, 50 Battery, 52 Electronic control unit for battery (battery ECU), 70 Electronic control unit for hybrid (HVECU), 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position Sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motor.

Claims (1)

An engine, a first motor, a drive shaft connected to an axle, a planetary gear in which three rotation elements are connected to an output shaft of the engine and a rotation shaft of the first motor, and a rotation shaft connected to the drive shaft A control device for a hybrid vehicle, comprising: the second motor that has been made; and a battery that exchanges electric power with the first motor and the second motor,
Set the upper limit rotational speed of the first motor to be higher than when the forward traveling position when said first and shift position in a range lower than the over-rotation determination rotation speed of the motor is reverse traveling position,
When the rotation speed of the first motor approaches the upper limit rotation speed, the upper limit torque of the first motor is reduced to reduce the rotation speed of the first motor compared to when the rotation speed is not approaching . Controlling the first motor to decrease with respect to the rotational speed;
Further, the amount of decrease in the upper limit torque is larger when the shift position is the reverse travel position and when the shift position is the forward travel position.
A control device for a hybrid vehicle.

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