JP5338471B2 - Shift control device for electric vehicle - Google Patents

Description

  The present invention relates to a shift control device for an electric vehicle including a stepped transmission having an input side connected to a drive motor and an output side connected to a drive wheel.

  2. Description of the Related Art Conventionally, there is provided a stepped transmission in which an input side is connected to a drive motor and an output side is connected to a drive wheel, and this transmission includes a high-side wet clutch that is fastened at the time of shifting from a low gear to a high gear. A speed change control device is known from, for example, Japanese Patent Application Laid-Open No. H10-228707.

This conventional shift control device for an electric vehicle keeps the hydraulic pressure of the high-side wet clutch at a constant value and shifts the motor speed by the friction torque of the high-side wet clutch when shifting from the low gear to the high gear with the accelerator depressed. It was decreasing.
Since the gear ratio is lowered by the speed change, the motor command torque is increased. Further, in order to prevent the output shaft torque from increasing due to the inertia torque, a correction for reducing the motor torque by the inertia torque is added.

JP 2004-203219 A

  However, since the conventional shift control device for an electric vehicle reduces the motor torque by a constant value in anticipation of the inertia torque, a negative torque corresponding to the inertia torque remains applied to the motor shaft even when the shift end condition is satisfied. It has become. For this reason, after the shift end condition is satisfied, the motor rotational speed continues to decrease and falls below the target motor rotational speed, which may cause a difference in the input / output rotational speed of the high-side wet clutch and cause a shift shock.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a shift control device for an electric vehicle capable of suppressing the occurrence of a shift shock while optimizing the shift time.

  In order to achieve the above object, the shift control device for an electric vehicle according to the present invention is configured so that the shift control means performs friction engagement during a shift as a shift process when shifting from the first shift stage to the second shift stage. A friction torque command that forms a slip engagement state that compensates for torque transmission from the motor to the drive wheels is output to the element, and after the shift that is the target motor torque after the shift to the second shift stage to the motor A shift correction process for outputting a torque command in which a correction torque proportional to the input / output rotational speed difference of the friction engagement element is added to the target motor torque in a direction to reduce the input / output rotational speed difference is included. A vehicle shift control device is provided.

In the shift control device for an electric vehicle according to the present invention, when shifting from the first shift stage to the second shift stage, the shift control means moves the drive wheel against the frictional engagement element during the shift. The friction torque command which compensates the torque transmission to is output.
In addition, during the gear shift, the correction torque proportional to the input / output rotational speed difference of the friction engagement element is added to the post-shift target motor torque after the shift to the second shift stage. Reduce the speed difference.

That is, when only the post-shift target motor torque is commanded to the motor, the change in the motor speed is small and the shift shock can be suppressed, but the shift time becomes longer.
On the other hand, when the motor is commanded only with a correction torque corresponding to the difference in input / output rotational speed of the friction engagement element, the shift time is fast, but the target motor torque is not generated after the shift is completed, and the friction torque generated by the friction engagement element The motor speed decreases and a shift shock occurs.

On the other hand, in the present invention, to output a motor torque command value obtained by adding a correction torque proportional to the input / output rotational speed difference of the friction engagement element to the target torque after the shift, when the input / output rotational speed difference is large, The correction torque increases and speeds up the motor speed reduction. Therefore, it is possible to suppress an increase in the shift time.
When the input / output rotational speed difference is reduced, the correction torque is reduced, and the motor torque after the shift of the motor torque is balanced with the friction torque of the frictional engagement element, so that the motor rotational speed is stabilized and the input / output rotational speed difference is balanced. Is kept within a certain value, it is possible to reduce the shift shock.
Therefore, it is possible to suppress the occurrence of a shift shock while optimizing the shift time.

1 is an overall system diagram illustrating a configuration of a drive system and a control system of a hybrid vehicle (an example of an electric vehicle) to which a shift control device for an electric vehicle according to a first embodiment is applied. FIG. 3 is a velocity diagram showing the rotation speed (number of rotations) of each rotation element in a drive system of a hybrid vehicle to which the shift control device for an electric vehicle according to the first embodiment is applied, with the vertical axis representing the rotation speed. It is a speed diagram which shows the low gear which fastened the low side dog clutch 8 which has in the drive system of the hybrid vehicle to which the transmission control apparatus of the electric vehicle of Example 1 was applied. It is a speed diagram which shows the high gear which fastened the high side wet clutch (friction fastening element) 7 which has in the drive system of the hybrid vehicle to which the transmission control apparatus of the electric vehicle of Example 1 was applied. 4 is a flowchart illustrating a flow of processing executed by an integrated controller when shifting from a low gear to a high gear in the shift control apparatus for an electric vehicle according to the first embodiment. In the shift control apparatus for an electric vehicle according to the first embodiment, motor rotation indicating the motor rotation speed ideal characteristic during power-up upshift, and the first rotation speed decrease change rate threshold value a1 and the second rotation speed decrease change rate threshold value a2 FIG. 3 is a flowchart showing a flow of a first torque correction process in the shift control apparatus for an electric vehicle according to the first embodiment. 6 is a flowchart showing a flow of a second torque correction process in the shift control apparatus for an electric vehicle according to the first embodiment. 3 is a time chart showing an operation example when shifting from a low gear to a high gear of the shift control apparatus for an electric vehicle according to the first embodiment. 6 is a flowchart illustrating a flow of a first torque correction process in the shift control device for an electric vehicle according to the second embodiment. 6 is a flowchart showing a flow of a second torque correction process in the shift control apparatus for an electric vehicle according to the second embodiment. FIG. 10 is an overall system diagram illustrating a configuration of a drive system and a control system of a hybrid vehicle (an example of an electric vehicle) to which a shift control device for an electric vehicle according to a third embodiment is applied. 10 is a time chart illustrating an operation example of a shift control device for an electric vehicle according to a third embodiment when shifting from a low gear to a high gear.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The clutch control device according to the embodiment of the present invention is provided in a motor (5) that applies drive torque to the drive wheels (32, 32) and a drive transmission path between the motor (5) and the drive wheels (32, 32). The stepped transmission (6) and a plurality of fastening elements (7, 7) including a friction fastening element (8) provided on the transmission (6) and capable of changing the friction torque by opening and fastening at the time of shifting. 8) and shift control means (46, 48) for executing shift control for switching the torque transmission state of the fastening elements (7, 8) when shifting the transmission (6), the shift control means (46, 48) is a shift process at the time of shifting from the first shift speed to the second shift speed, during the shift, the motor (5) to the drive wheel ( 32, 32) forms a slip fastening state that compensates for torque transmission to The frictional torque command is output, and the input / output rotation of the frictional engagement element (8) is changed to the post-shift target motor torque, which is the target motor torque after the shift to the second shift stage, with respect to the motor (5). The shift control apparatus for an electric vehicle includes a shift correction process for outputting a torque command in which a correction torque proportional to the number difference is added in a direction to decrease the input / output rotation speed difference.

  A clutch control apparatus according to Embodiment 1 of the best mode for carrying out the invention will be described with reference to FIGS.

(Configuration of Example 1)
FIG. 1 is an overall system diagram illustrating a configuration of a drive system and a control system of a hybrid vehicle (an example of an electric vehicle) to which the control device of the first embodiment is applied. The drive system configuration and control system configuration will be described below with reference to FIG.

  The hybrid vehicle drive system of the first embodiment includes an engine 1, a damper 2, a first motor generator 3, an oil pump 4, a second motor generator (motor) 5, and a transmission 6, as shown in the figure. , A high-side wet clutch (friction engagement element) 7, a low-side dog clutch 8, and a planetary gear device 10.

  The engine 1 distributes the output torque to the power generation torque to the first motor generator 3 and the travel torque by the planetary gear device 10. Then, the second motor generator 5 outputs torque via the transmission 6 using the electric power generated by the first motor generator 3. Then, the output torque from the planetary gear device 10 and the output torque from the transmission 6 are combined by the final output shaft 23.

  The planetary gear device 10 includes a single pinion planetary gear having a ring gear 11, a pinion 12, a sun gear 13, and a carrier 14 that supports the pinion 12. An output gear 15 is connected to the ring gear 11. The engine 1 is connected to the carrier 14 via the damper 2. The first motor generator 3 is connected to the sun gear 13. The oil pump 4 is connected to the sun gear 13 and the carrier 14. That is, it has a continuously variable transmission function that automatically determines the rotational speed of the output gear 15 (ring gear 11) when the rotational speed of the first motor generator 3 (sun gear 13) and the rotational speed of the engine 1 (carrier 14) are determined. . Note that the output gear 15 meshes with a high-side driven gear 21 fixed to the final output shaft 23.

  The transmission 6 is a stepped transmission, and the high-side drive gear 25 that is rotatably supported by the motor output shaft 29 via a bearing 27, and the motor output shaft 29 and the high-side drive gear 25 are slidably connected. A high-side wet clutch 7, a low-side drive gear 24 rotatably supported on a motor output shaft 29 via a bearing 28, a low-side dog clutch 8 that meshes and connects the motor output shaft 29 and the low-side drive gear 24; It is comprised.

  The second motor generator 5 is connected to the motor output shaft 29. The high side driven gear 21 fixed to the final output shaft 23 meshes with the high side drive gear 25. The low-side drive gear 24 meshes with the low-side driven gear 22 fixed to the final output shaft 23. When the high-side wet clutch 7 is engaged and the low-side dog clutch 8 is released, the high gear is determined by the gear ratio between the high-side drive gear 25 and the high-side driven gear 21, and the high-side wet clutch 7 is released. When the side dog clutch 8 is engaged, a low gear determined by the gear ratio between the low side drive gear 24 and the low side driven gear 22 is obtained. That is, the transmission 6 has a two-stage shift function of a high gear and a low gear. The high-side wet clutch 7 is a multi-plate or single-plate wet clutch.

  Both ends of the final output shaft 23 are supported by bearings 26, 26, and the final output gear 30 is fixed together with the high side driven gear 21 and the low side driven gear 22. The torque transmitted to the final output gear 30 is transmitted to a pair of drive wheels 32 and 32 via a final reduction gear (not shown) and a differential device 31.

  The control system of the hybrid vehicle of the first embodiment includes a first inverter 41, a second inverter 42, a battery 43, a motor controller 44, an engine controller 45, a shift controller (shift control means) 46, and a CAN communication line. 47 and an integrated controller (shift control means) 48.

  The motor controller (charge amount detection means) 44 controls the operating point (first torque Tm1, first rotation speed Nm1) of the first motor generator 3 according to a control command for the first inverter 41. Further, the operating point (second torque Tm2, second rotation speed Nm2) of the second motor generator 5 is controlled by a control command to the second inverter 42. Further, the motor controller 44 monitors the battery charge amount SOC indicating the charge capacity of the battery 43, and this battery charge amount SOC information is used as control information for both the motor generators 3, 5, and the CAN communication line 47. To the integrated controller 48.

  The engine controller 45 controls the operating point (engine torque Te, engine speed Ne) of the engine 1 by a control command to an electronic control throttle actuator (not shown).

  The shift controller 46 controls the operating point (engagement / slip engagement / release) of the high-side wet clutch 7 by a control command to a friction clutch actuator (not shown). The operating point (engagement / release) of the low-side dog clutch 8 is controlled by a control command to a dog clutch actuator (not shown).

The integrated controller 48 manages the energy consumption of the entire vehicle and bears the function of running the hybrid vehicle with maximum efficiency while ensuring the required driving force. The integrated controller 48 is connected to the motor controller 44 and the engine via the CAN communication line 47. The controller 45 is connected to the speed change controller 46 and the like. The integrated controller 48 includes an accelerator operation amount sensor 49, a vehicle speed sensor 50, an engine speed sensor 51, a first motor generator speed sensor 52, a second motor generator speed sensor 53, a dog clutch sensor 54, a battery temperature sensor 55, an oil Necessary information is input from the temperature sensor 56 or the like. Based on the input information, a predetermined calculation process is performed, and operating point command values are output to the controllers 44, 45, 46.
The dog clutch sensor 54 is a sensor that detects whether the low-side dog clutch 8 is in the engaged state or the released state.
The battery temperature sensor 55 is a sensor that detects the temperature of the battery 43.
The oil temperature sensor 56 detects the oil temperature supplied from the oil pump 4 to the transmission 6 and the high-side wet clutch 7.

  FIG. 2 is a velocity diagram in which the rotation speed (number of rotations) of each rotation element included in the drive system of the hybrid vehicle to which the control device of the first embodiment is applied is represented on the vertical axis. FIG. 3 is a velocity diagram illustrating a low gear in which a low-side dog clutch 8 having a drive system of a hybrid vehicle to which the control device of the first embodiment is applied is fastened. FIG. 4 is a velocity diagram showing a high gear in which a high-side wet clutch (friction engagement element) 7 included in a drive system of a hybrid vehicle to which the control device of the first embodiment is applied.

  As shown in FIG. 2, the electric transmission portion includes a first motor generator 3 connected to the planetary gear device 10, the engine 1, and an output gear 15. The electric transmission portion is a continuously variable step in which the rotational speed of the output gear 15 is automatically determined when the rotational speed of the first motor generator 3 and the rotational speed of the engine 1 are determined by the two-degree-of-freedom planetary gear device 10. Has a shifting function.

  The motor speed change portion includes a second motor generator 5 connected to the transmission 6 via a motor output shaft 29, a high-side wet clutch 7, a low-side dog clutch 8, a high-side drive gear 25 that is a meshing pair, and a high-side. A side driven gear 21, a low-side drive gear 24 and a low-side driven gear 22 that are meshing pairs are configured. The motor transmission portion is a two-stage shift that switches between a high gear by engaging the high-side wet clutch 7 (releasing the low-side dog clutch 8) and a low gear by engaging the low-side dog clutch 8 (releasing the high-side wet clutch 7). It has a function.

In the final output shaft 23, the engine direct drive torque from the electric speed change portion and the motor drive torque from the motor speed change portion are combined, and the combined drive torque transmitted to the final output gear 30 is the final reduction gear and the differential device 31. Is transmitted to the pair of drive wheels 32, 32, and the vehicle speed V is obtained.
At this time, as shown in FIG. 3, when the rotation speed of the second motor generator 5 is increased to bring the low-side dog clutch 8 into the engaged state and the high-side wet clutch 7 is released, the low gear is selected. On the other hand, as shown in FIG. 4, when the rotational speed of the second motor generator 5 is lowered to bring the high-side wet clutch 7 into the engaged state and the low-side dog clutch 8 is released, the high gear is selected.

  Here, the reason why the high-side wet clutch 7 is used in the high gear and the low-side dog clutch 8 is used in the low gear will be described. For example, when both are friction clutches, drag loss and hydraulic pump loss occur, and the loss is particularly noticeable in a low gear having a large transmitted torque. Further, for example, when both are dog clutches, there is an advantage that there is no loss, but it is necessary to completely release both the engagement side and the release side at the time of shifting, and to perform the engagement in rotation synchronization. That is, rotation synchronous control is required and torque loss occurs during the shift transition period. Therefore, the high gear uses the high-side wet clutch 7 that does not require rotation synchronization control, the low gear uses the low-side dog clutch 8 that suppresses loss, and the high-side wet clutch 7 during the shift transition period from the high gear to the low gear. Torque loss is compensated by the frictional force.

(Processing flow during upshifting)
Next, the flow of processing executed by the integrated controller 48 when upshifting from the low gear to the high gear will be described based on the flowchart of FIG. During upshifting, the low gear corresponds to the first gear and the high gear corresponds to the second gear.

  In step S1, it is determined whether or not the vehicle speed is equal to or higher than a preset shift vehicle speed αkm / h while traveling in low gear. If the vehicle speed has not reached the shift vehicle speed αkm / h, one process is performed without shifting. If the transmission vehicle speed αkm / h is exceeded, the process proceeds to step S2 to execute the shift from the low gear to the high gear. That is, in step S1, it is determined from the vehicle speed whether or not an upshift is performed.

  In step S2, it is determined whether or not the accelerator opening is greater than or equal to a predetermined opening determination value β%. If the opening determination value is less than β%, the process proceeds to step S3. Advances to step S4. This step S2 determines whether it is an upshift at power-up (acceleration) or an upshift at power-off (deceleration). In the case of an upshift at power-off, the process proceeds to step S3. In the case of a shift, the process proceeds to step S4, and the process proceeds to a shift process involving the shift correction process of the first embodiment.

  In the case of an upshift at the time of power-off, the second motor generator 5 is in a state where no torque is output. In this case, in step S3, both the low-side dog clutch 8 and the high-side wet clutch 7 are once released. After that, the high-side wet clutch 7 is engaged, and the shift from the low gear to the high gear is executed.

In the first step S4 that proceeds in the case of an upshift at the time of power-up, a release command is output to the low-side dog clutch 8, and at the same time, a half-clutch (slip engagement) command is output to the high-side wet clutch 7. .
In the case of this upshift at the time of power-up, the second motor generator 5 outputs torque, and when a half-clutch command is output to the high-side wet clutch 7, the hydraulic pressure of the high-side wet clutch 7 is gradually increased. The friction torque is gradually increased, and the driving force transmitted by the low gear is transferred to the high gear side. As a result, the torque applied to the low-side dog clutch 8 becomes zero, and the low-side dog clutch 8 is released.

  In step S5, it is determined whether or not the low-side dog clutch 8 is released based on a signal from the dog clutch sensor 54. If it is released, the process proceeds to step S6, and if it is not released, the process returns to step S4.

  In step S6, the hydraulic pressure of the high-side wet clutch 7 is increased, the driving force is compensated by the friction torque of the high-side wet clutch 7, and the motor rotational speed Nm is decreased. A value obtained by adding a motor negative torque proportional to the input / output rotational speed difference of 7 is commanded to the second motor generator 5 as a target motor torque, and the process proceeds to step S7.

In step S7, it is determined whether or not the motor rotation decrease rate of change is smaller than a preset first rotation number decrease rate of change threshold a1, and if it is smaller than the first rotation number decrease rate of change threshold a1, the process proceeds to step S9. If it is greater than the first rotation speed decrease rate of change threshold a1, the process proceeds to step S8.
Further, in step S8, it is determined whether or not the motor rotational speed decrease change rate is larger than a preset second rotational speed decrease change rate threshold value a2, and if larger than the second rotational speed decrease change rate threshold value a2, step is performed. The process proceeds to S10, and if it is smaller than the second rotation speed decrease change rate threshold value a2, the process proceeds to Step S11.

Here, the first rotation speed decrease change rate threshold value a1 and the second rotation speed decrease change rate threshold value a2 will be described with reference to FIG.
The target motor torque at the time of the shift is a value obtained by adding a motor negative torque proportional to the input / output rotational speed difference of the high-side wet clutch 7 to the post-shift target motor torque. In this case, when the input / output rotational speed difference is large, the target motor torque is obtained by adding the motor negative torque having a large absolute value to the post-shift target motor torque, so that the driving torque of the second motor generator 5 is relative. The motor rotational speed Nm is rapidly reduced by the friction torque of the high-side wet clutch 7.

Thus, when the motor rotation speed Nm decreases, if the motor rotation speed decrease change rate is relatively small, the driver feels that the shift time is long. Therefore, the first rotation speed decrease change rate threshold value a1 is set as a reference value for determining whether or not the driver feels that the shift time is long.
On the other hand, when the motor rotation speed decrease rate of change is relatively large, the driver feels a shift shock. Therefore, the second rotation speed decrease change rate threshold value a2 is set as a reference value for determining whether or not the driver feels a shift shock.
Therefore, by controlling the motor rotation speed decrease change rate to an ideal decrease range between the first rotation speed decrease change threshold value a1 and the second rotation speed decrease change threshold value a2, it is difficult to feel a shift shock and the shift time. The gear shift which is not too long can be executed.

In step S9 that proceeds when the motor rotational speed decrease rate of change is smaller than the first rotational speed decrease rate of change threshold value a1, first torque correction is performed, and the process proceeds to step S11. This first torque correction is a correction that increases the rate of decrease in motor rotation speed (makes the slope steep), and is proportional to the friction torque of the high-side wet clutch 7 and the difference in input / output rotation speed of the wet clutch depending on the vehicle state. In step S10 that proceeds when the motor negative torque is increased to increase the negative torque applied to the motor output shaft 29 while the motor rotational speed decrease rate of change is greater than the second rotational speed decrease rate threshold a2. Then, the second torque correction is executed, and the process proceeds to step S11. This second torque correction is a correction that lowers the rate of change in the motor speed reduction (makes the slope gentle), and is proportional to the friction torque of the high-side wet clutch 7 and the difference in the input / output speed of the wet clutch according to the vehicle state. The negative torque applied to the motor output shaft 29 is reduced by reducing either of the negative motor negative torque.

  In both the torque corrections in steps S9 and S10 described above, whether the correction is performed with the friction torque of the high-side wet clutch 7 or the motor negative torque proportional to the difference in the input / output speed of the wet clutch depends on the battery charge amount SOC, the battery The determination is based on the vehicle state including the temperature Tb and the oil temperature To. Details thereof will be described later.

  When the difference between the input and output rotational speeds of the high-side wet clutch 7 becomes small, the second motor generator 5 outputs only the target torque after the shift, and is in a state substantially balanced with the friction torque generated by the high-side wet clutch 7. Therefore, in step S11, it is determined whether or not the input / output rotation difference of the high-side wet clutch 7 has become smaller than a preset rotation difference reference value γrpm that can be determined to be synchronized on the input / output side. Advances to step S12, and if not smaller, returns to step S7.

In step S12, the hydraulic pressure of the high-side wet clutch 7 is increased to shift to a fully engaged state, and the process proceeds to step S13.
In step S13, it is determined whether or not the hydraulic pressure of the high-side wet clutch 7 has reached the maximum hydraulic pressure value. If the maximum hydraulic pressure value is reached, the shift process is terminated. If the maximum hydraulic pressure value has not been reached, the process returns to step S11.

(Torque correction)
Next, the first torque correction and the second torque correction described above will be described. In these torque corrections, as described above, whether to correct with the friction torque of the high-side wet clutch 7 or to correct with the motor negative torque proportional to the difference in the input / output speed of the wet clutch is selected according to the vehicle condition. .

  As the vehicle state, in the first embodiment, the battery charge amount SOC, the battery temperature Tb, and the oil temperature To are used, and the determination order is set in the order of battery charge amount SOC> battery temperature Tb> oil temperature To. Yes.

  The reason is that the battery charge amount SOC is closely related to fuel consumption and power performance. That is, when the battery charge amount SOC is high in a scene with many decelerations, regeneration cannot be performed to avoid an overcharge state, and regeneration energy cannot be obtained efficiently. On the other hand, when the battery charge amount SOC is small in a scene that requires motor assist, motor assist cannot be performed to avoid discharging the battery 43, and power performance is significantly reduced. Therefore, the battery charge amount SOC is set as the highest priority.

  Further, when the battery temperature Tb is not stable, input / output restriction is imposed on the battery 43, regeneration and motor assist cannot be performed, and both fuel consumption and power performance are reduced. For this reason, the battery temperature Tb was set as the second criterion.

Further, the oil temperature To is set to the third in terms of power performance because the target friction torque can be obtained when the oil temperature state is stable.
(First torque correction)
Next, the flow of the first torque correction process executed in step S9 will be described based on the flowchart of FIG.
In step S21, it is determined whether or not the battery charge amount SOC is greater than a preset first charge amount threshold value v1, and if greater than the first charge amount threshold value v1 (close to overcharging), the process proceeds to step S22. If it is not greater than the first charge amount threshold value v1 (there is room until overcharge occurs), the process proceeds to step S23. The first charge amount threshold value v1 is a threshold value for determining the overcharge state, and is set immediately before the overcharge state.

  In step S22 which proceeds when the battery 43 is in a state close to overcharging, a correction for increasing the friction torque of the high-side wet clutch 7 is performed.

  In step S23 that proceeds when the battery 43 has a margin for overcharge, it is determined whether or not the battery charge amount SOC is smaller than the second charge amount threshold value v2, and is smaller than the second charge amount threshold value v2 (nearly charged). ), The process proceeds to step S27, and if it is not smaller than the second charge amount threshold v2 (there is a sufficient charge amount), the process proceeds to step S24. The second charge amount threshold value v2 is a threshold value for determining the state of insufficient charge / discharge amount, and is set immediately before the charge amount becomes insufficient.

  In step S27, motor negative torque increase correction proportional to the input / output rotational speed difference of the high-side wet clutch 7 is performed.

  In step S24, it is determined whether or not the battery temperature Tb detected by the battery temperature sensor 55 is lower than the first temperature threshold t1, and if it is lower than the first temperature threshold t1, the process proceeds to step S27, and from the first temperature threshold t1. If not, the process proceeds to step S25. The first temperature threshold t1 is set to a low temperature at which the battery 43 is positively charged and discharged.

  In step S25, it is determined whether or not the battery temperature Tb is higher than the second temperature threshold t2. If the battery temperature Tb is higher than the second temperature threshold t2, the process proceeds to step S22, and if the battery temperature Tb is not higher than the second temperature threshold t2. Advances to step S26. The second temperature threshold value t2 is set to a high temperature at which battery input / output restriction needs to be applied.

  In step S26, it is determined whether or not the oil temperature To detected by the oil temperature sensor 56 is greater than the oil temperature threshold T1, and if it is greater than the oil temperature threshold T1, the process proceeds to step S27 and is not greater than the oil temperature threshold T1. In this case, the process proceeds to step S22. The oil temperature threshold T1 is a normal oil temperature average value.

(Second torque correction)
Next, the flow of the second torque correction process executed in step S10 will be described based on the flowchart of FIG.
In step S31, it is determined whether or not the battery charge amount SOC is greater than a preset first charge amount threshold value v1, and if greater than the first charge amount threshold value v1, the process proceeds to step S37, where the first charge amount threshold value is determined. If it is not greater than v1, the process proceeds to step S32.

  In step S32, it is determined whether or not the battery charge amount SOC is smaller than the second charge amount threshold value v2. If the battery charge amount SOC is smaller than the second charge amount threshold value v2, the process proceeds to step S36 and is smaller than the second charge amount threshold value v2. If not, the process proceeds to step S33.

  In step S33, it is determined whether or not the battery temperature is lower than the first temperature threshold t1, and if lower than the first temperature threshold t1, the process proceeds to step S36, and if not lower than the first temperature threshold t1, the process proceeds to step S34. move on.

  In step S34, it is determined whether or not the battery temperature Tb is higher than the second temperature threshold t2. If the battery temperature Tb is higher than the second temperature threshold t2, the process proceeds to step S37, and if the battery temperature Tb is not higher than the second temperature threshold t2. Advances to step S35.

  In step S35, it is determined whether or not the oil temperature To is higher than the oil temperature threshold T1. If the oil temperature To is higher than the oil temperature threshold T1, the process proceeds to step S36, and if not higher than the oil temperature threshold T1, the process proceeds to step S37.

In step S36, a reduction correction of the friction torque of the high-side wet clutch 7 is performed.
In step S37, motor negative torque decrease correction proportional to the input / output rotational speed difference of the high-side wet clutch 7 is performed.

(During downshift)
Next, the control at the time of shifting from the high gear to the low gear will be briefly described. When shifting from the high gear to the low gear, the high gear corresponds to the first gear and the low gear corresponds to the second gear.
In other words, during the shift transition period from the high gear to the low gear, the motor torque control for making the second motor generator 5 coincide with the target torque (the motor rotation speed Nm is determined by the load acting on the second motor generator 5 during the torque control). ) To a motor rotational speed control that matches the target rotational speed (the motor torque is determined by a load acting on the second motor generator 5 during the rotational speed control). Then, the high-side wet clutch 7 is put into a half-clutch state, and the rotational speed of the second motor-generator 5 is increased while compensating the driving force to suppress the driving torque from being lost due to the friction torque, and the input rotational speed ( = The rotational speed of the second motor generator 5) is synchronized with the output rotational speed of the low-side dog clutch 8 (determined by the vehicle speed and gear ratio), and the low-side dog clutch 8 is engaged and fastened at the rotational speed synchronization timing.

In such a downshift, the post-shift target motor torque is changed to the input / output rotational speed difference of the high-side wet clutch 7 so that the rate of change in the motor rotational speed is within a preset ideal range. Shift correction processing is performed to instruct the second motor generator 5 to target motor torque obtained by adding proportional motor positive torque.
This correction is the reverse of the upshift, and if the motor rotation speed increase rate of change is too large, a relatively large motor positive torque is added to suppress the motor rotation rate increase, and the motor rotation speed increase rate of change is If it is too small, a relatively small motor positive torque is added to promote the increase.

(Operation of Example 1)
Next, the operation of the first embodiment will be described based on the time chart of FIG.
In the running example shown in this time chart, at t = 0, an acceleration operation is performed in which the accelerator is gradually depressed in the low gear state.

  As a result of this acceleration operation, at time t1, the accelerator opening is equal to or greater than the opening determination value β%, the vehicle speed reaches the shift vehicle speed αkm / h, and the upshift condition is satisfied. (Steps S1-> S2-> S4).

  Therefore, at time t1, a release command is output toward the low-side dog clutch 8, while a slip engagement (half-clutch) command is output toward the high-side wet clutch 7, and the hydraulic pressure increases.

Thereafter, at time t2, the friction torque (hydraulic pressure) of the high-side wet clutch 7 becomes constant and is maintained in the half-clutch state.
At this time, since the friction torque of the high-side wet clutch 7 becomes equal to the motor torque, the torque applied to the low-side dog clutch 8 becomes zero, and the opening operation of the low-side dog clutch 8 is started. At time t3, the release operation of the low-side dog clutch 8 is completed (indicated by a dotted line in the figure).

  When the release of the low-side dog clutch 8 is detected by the dog clutch sensor 54, the hydraulic pressure of the high-side wet clutch 7 is raised to the hydraulic pressure that compensates the driving force toward the drive wheels 32 and 32. Therefore, the driving torque of the output shaft is compensated by the friction torque of the high-side wet clutch 7. This hydraulic pressure becomes constant at the time t4.

  On the other hand, the second motor generator 5 is commanded with a target motor torque obtained by adding a negative motor torque proportional to the input / output rotational speed difference of the high-side wet clutch 7 to the post-shift target motor torque.

  Further, based on the rate of change in the motor rotational speed at this time, torque correction is executed as to whether the friction torque of the high-side wet clutch 7 or the torque of the second motor generator 5 is increased or decreased as necessary. The

  In this case, if the motor rotation speed decrease change rate is between the first rotation speed decrease change rate threshold value a1 and the second rotation speed decrease change rate threshold value a2, torque correction is not executed.

Further, when the motor rotation speed decrease change rate is smaller than the first rotation speed decrease change rate threshold value a1, the friction torque of the high-side wet clutch 7 is increased or the target motor torque is set according to the vehicle state. Torque correction (first torque correction) is executed to add a negative motor torque proportional to the input / output rotational speed difference of the high-side wet clutch 7 (step S7 → S9).
Thereby, the motor rotation speed decrease change rate is increased, and the motor rotation speed decrease change rate is controlled within the ideal characteristic range shown in FIG.

Further, when the motor rotation speed decrease change rate is larger than the second rotation speed decrease change rate threshold value a2, the friction torque of the high-side wet clutch 7 is reduced or the target motor torque is set according to the vehicle state. Torque correction (second torque correction) is executed to subtract the motor negative torque proportional to the input / output rotational speed difference of the high-side wet clutch 7 (steps S7 → S8 → S10).
As a result, the motor rotation speed decrease change rate is reduced, and the motor rotation speed decrease change rate is controlled within the ideal characteristic range shown in FIG.

  By the torque control of the second motor generator 5 and the friction torque control of the high-side wet clutch 7 as described above, the input / output rotational speed difference of the high-side wet clutch 7 is reduced, and the motor rotational speed Nm is also rapidly reduced. When the input / output rotational speed difference becomes equal to or smaller than the rotational difference reference value γrpm at time t5, the hydraulic pressure of the high-side wet clutch 7 is increased toward the maximum pressure (step S11 → S12), and at time t6, the maximum is reached. The pressure is reached and the shift from the low gear to the high gear is completed (step S13).

(Effect of Example 1)
As described above, the effects listed below can be obtained in the first embodiment.
a) During the shift from the low gear to the high gear, the driving force toward the drive wheels 32, 32 is compensated by the friction torque of the high-side wet clutch 7, and the target motor torque is set to the high-side wet after the shift. A value obtained by adding a motor negative torque proportional to the input / output rotational speed difference of the clutch 7 was used.
For this reason, when the input / output rotational speed difference of the high-side wet clutch 7 is large, the motor negative torque component becomes large, and the reduction in the motor rotational speed can be accelerated and the shift time can be shortened. When the input / output rotation speed difference is reduced, the motor negative torque component is reduced, and the motor torque applied to the second motor generator 5 becomes the post-shift target torque and the friction torque generated by the high-side wet clutch 7, and the two are balanced. For this reason, the motor rotation speed Nm is stabilized, the input / output rotation speed difference of the high-side wet clutch 7 can be kept within a certain value, and the shift shock can be reduced.

  Even when shifting from the high gear to the low gear, if the difference between the input and output rotational speeds of the high-side wet clutch 7 is large, the motor positive torque component becomes large, thereby increasing the motor rotational speed and shortening the shift time. It becomes possible. When the input / output rotation speed difference is reduced, the motor positive torque component is reduced, and the motor torque applied to the second motor generator 5 becomes the post-shift target torque and the friction torque generated by the high-side wet clutch 7, and the two are balanced. For this reason, the motor rotation speed Nm is stabilized, the input / output rotation speed difference of the high-side wet clutch 7 can be kept within a certain value, and the shift shock can be reduced.

b) Correction of increase / decrease of the friction torque of the high-side wet clutch 7 and input / output rotation number of the high-side wet clutch 7 according to the vehicle state so that the rate of change in motor rotation number decrease is within the ideal decrease range during gear shifting Increase / decrease correction of motor negative torque proportional to the difference (motor positive torque at the time of shift down) is selected and performed.
Therefore, the motor performance can be ensured by ideally changing the motor rotation speed Nm according to the vehicle state.

c) When the vehicle state of b) is close to the overcharge state according to the battery charge amount SOC and the motor rotation speed decrease rate of change, the torque increase correction is performed so that the power generation tendency of the second motor generator 5 is weakened. The friction torque of the high-side wet clutch 7 is sometimes increased, and the motor generator negative torque is decreased when the torque reduction is corrected.
On the other hand, when close to the undercharged state, the motor negative torque is increased at the time of torque increase correction and the friction torque of the high-side wet clutch 7 is decreased at the time of torque decrease correction so that the power generation tendency of the second motor generator 5 becomes stronger. I tried to make it.
Therefore, the battery charge amount SOC is stabilized, the driving performance of the second motor generator 5 due to the battery charge amount SOC is prevented from being generated, and the power performance is secured, while the shift time is shortened and the shift shock is reduced. It becomes possible to suppress it.

d) As the vehicle state of b), the motor negative torque is increased at the time of torque increase correction so that the power generation tendency of the second motor generator 5 becomes stronger at low temperatures according to the battery temperature Tb and the motor rotation speed decrease rate of change. The friction torque of the high-side wet clutch 7 is reduced at the time of torque reduction correction. On the other hand, the friction torque of the high-side wet clutch 7 is increased during the torque increase correction and the motor generator negative torque is decreased during the torque decrease correction so that the power generation tendency of the second motor generator 5 becomes weak at high temperatures.
Therefore, it is possible to stabilize the battery temperature Tb and prevent the second motor generator 5 from being stopped due to the battery temperature Tb so as to ensure the power performance while shortening the shift time and suppressing the shift shock. It becomes possible to plan.

e) As the vehicle state of b) above, according to the oil temperature To and the motor rotation speed decrease rate of change, the friction torque is increased at the time of torque increase correction so that the heat generation tendency of the high-side wet clutch 7 becomes stronger at low temperatures, Reduced motor negative torque when correcting torque reduction.
On the other hand, the motor negative torque is increased at the time of torque increase correction and the friction torque is decreased at the time of torque decrease correction so that the heat generation tendency of the high-side wet clutch 7 becomes weak at high temperatures.
Therefore, by stabilizing the oil temperature To, it is possible to stabilize the performance of the power transmission system including the high-side wet clutch 7 to ensure the power performance, while shortening the shift time and suppressing the shift shock. It becomes possible.

(Other examples)
Other embodiments will be described below. Since these other embodiments are modifications of the first embodiment, only the differences will be described, and the configuration common to the first embodiment or the other embodiments will be described. The description is omitted by giving a common reference numeral.

A transmission control apparatus for an electric vehicle according to a second embodiment will be described.
In the second embodiment, when executing the first torque correction and the second torque correction, a vehicle state that determines whether to select increase / decrease in friction torque of the high-side wet clutch 7 or increase / decrease in motor negative torque is selected. Is a different example from the first embodiment. That is, in the second embodiment, when protecting the battery 43, the temperature is a top priority, and torque correction is performed with the priority of battery temperature Tb> battery charge amount SOC> oil temperature To.

Hereinafter, the flow of processing of the first torque correction and the second torque correction in the second embodiment will be described in detail.
(First torque correction)
The flowchart of FIG. 10 shows the flow of the first torque correction process in the second embodiment. In step S201, it is determined whether or not the battery temperature Tb detected by the battery temperature sensor 55 is lower than the first temperature threshold t1. If it is lower than the first temperature threshold t1, the process proceeds to step S207. If it is not lower than the first temperature threshold t1, the process proceeds to step S202.

  In step S202, it is determined whether or not the battery temperature Tb is higher than the second temperature threshold t2. If the battery temperature Tb is higher than the second temperature threshold t2, the process proceeds to step S206, and if the battery temperature Tb is not higher than the second temperature threshold t2. Advances to step S203.

  In step S203, it is determined whether or not the battery charge amount SOC is larger than the first charge amount threshold value v1. If the battery charge amount SOC is larger than the first charge amount threshold value v1 (close to overcharge), the process proceeds to step S206. When it is not larger than the charge amount threshold value v1 (there is room until overcharge occurs), the process proceeds to step S204. The first charge amount threshold value v1 is a threshold value for determining the overcharge state, and is set immediately before the overcharge state.

  In step S204, it is determined whether or not the battery charge amount SOC is smaller than the second charge amount threshold value v2. If the battery charge amount SOC is smaller than the second charge amount threshold value v2 (close to insufficient charging), the process proceeds to step S207 and the second charge is performed. If it is not smaller than the amount threshold v2 (there is a surplus charge amount), the process proceeds to step S205.

  In step S205, it is determined whether or not the oil temperature To detected by the oil temperature sensor 56 is greater than the oil temperature threshold T1, and if it is greater than the oil temperature threshold T1, the process proceeds to step S207 and is not greater than the oil temperature threshold T1. In this case, the process proceeds to step S206.

In step S206, a correction for increasing the friction torque of the high-side wet clutch 7 is performed.
In step S207, motor negative torque increase correction proportional to the input / output rotational speed difference of the high-side wet clutch 7 is performed.

(Second torque correction)
Next, the flow of the second torque correction process in the second embodiment will be described based on the flowchart of FIG.

  In step S211, it is determined whether or not the battery temperature is lower than the first temperature threshold t1, and if lower than the first temperature threshold t1, the process proceeds to step S216, and if not lower than the first temperature threshold t1, the process proceeds to step S212. move on.

  In step S212, it is determined whether or not the battery temperature Tb is higher than the second temperature threshold t2. If the battery temperature Tb is higher than the second temperature threshold t2, the process proceeds to step S217, and if the battery temperature Tb is not higher than the second temperature threshold t2. Advances to step S213.

  In step S213, it is determined whether or not the battery charge amount SOC is larger than a preset first charge amount threshold value v1, and if larger than the first charge amount threshold value v1, the process proceeds to step S217, where the first charge amount threshold value is determined. If it is not greater than v1, the process proceeds to step S214.

  In step S214, it is determined whether or not the battery charge amount SOC is smaller than the second charge amount threshold value v2. If the battery charge amount SOC is smaller than the second charge amount threshold value v2, the process proceeds to step S216, and is smaller than the second charge amount threshold value v2. If not, the process proceeds to step S215.

  In step S215, it is determined whether or not the oil temperature To is higher than the oil temperature threshold T1, and if the oil temperature To is higher than the oil temperature threshold T1, the process proceeds to step S216. If not, the process proceeds to step S217.

In step S216, the frictional torque of the high-side wet clutch 7 is reduced and corrected.
In step S217, motor negative torque decrease correction proportional to the input / output rotational speed difference of the high-side wet clutch 7 is performed.

(Effect of Example 2)
When the battery temperature Tb is not stable, input / output restriction is imposed on the battery 43, so that regeneration and motor assist cannot be performed, and both fuel efficiency and power performance are reduced.
For this reason, in the second embodiment, when the torque correction during the shift is performed, the battery temperature Tb is given the highest priority, the battery temperature Tb is stabilized, and the second motor generator 5 is driven by the battery temperature Tb. It is possible to shorten the shift time and suppress the shift shock while ensuring the power performance without causing the stop state.

(Configuration of Example 3)
The third embodiment is a modification of the first embodiment. As shown in FIG. 12, a low-side wet clutch 308 such as a multi-plate clutch similar to the high-side wet clutch 7 is used as a fastening element to be fastened when a low gear is formed. Is an example.

  In this case, although illustration is omitted, in the flowchart at the time of shifting described in the first embodiment, a release command is output to the low-side wet clutch 308 in step S4, and it is determined whether the low-side wet clutch 308 is released in step S5. This is different from the first embodiment.

  As shown in the time chart of FIG. 13, when a release command is output to the low-side wet clutch 308, the friction torque gradually decreases at timings t21 to t22.

  Therefore, even in the high-side wet clutch 7, a hydraulic pressure command for compensating the driving force is output in accordance with the release timing (t22) of the low-side wet clutch 308. Thereafter, at time t23 when the input / output rotational speed difference of the high-side wet clutch 7 becomes less than the rotation difference reference value γrpm, a hydraulic pressure command for completely engaging the high-side wet clutch 7 is output. , T24, the fastening is completed.

  In the third embodiment, at the time of shifting from the high gear to the low gear, the driving force may be secured by slip-engaging the high-side wet clutch 7 as in the first embodiment, or the low-side wet clutch 308. May be performed by slip fastening.

  In the third embodiment, as in the first embodiment, in addition to the effects a) to e) described above, since the low-side wet clutch 308 is provided, the control accuracy of the transmission torque is increased.

  As mentioned above, although the clutch control apparatus of this invention has been demonstrated based on Embodiment and Examples 1-3, a concrete structure is not restricted to these Examples, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.

  For example, in the first to third embodiments, a hybrid vehicle including the engine 1 as a drive source is shown as an electric vehicle. However, the electric vehicle is not limited to this, and a vehicle including only a motor as a drive source. It can also be applied to.

  In the first to third embodiments, a motor generator that can perform power running and regeneration is shown as the motor. However, a motor generator that performs only power running may be used.

5 Second motor generator (motor)
6 Transmission 7 High-side wet clutch (friction engagement element)
8 Low side dog clutch (fastening element)
32 Drive wheel 46 Shift controller (shift control means)
48 Integrated controller (shift control means)
54 Dog clutch sensor 55 Battery temperature sensor 56 Oil temperature sensor 308 Low side wet clutch (engaging element)
a1 1st rotation speed decrease change rate threshold value a2 2nd rotation speed decrease change rate threshold value

Claims (4)

A motor that applies drive torque to the drive wheels;
A stepped transmission provided in a drive transmission path between the motor and the drive wheels;
A plurality of fastening elements including a friction fastening element that is provided in the transmission and that can be opened and fastened to change the friction torque when the shift stage is switched;
Shift control means for executing shift control for switching the torque transmission state of the fastening element at the time of shifting of the transmission;
With
The shift control means is a shift process when shifting from the first shift stage to the second shift stage.
Depending on the vehicle condition, the change of the motor rotation speed will be within the preset range during the gear shift .
A correction for outputting a friction torque command that forms a slip engagement state for compensating torque transmission from the motor to the drive wheel for the friction engagement element ;
A correction torque proportional to the input / output rotational speed difference of the friction engagement element is added to the post-shift target motor torque, which is the target motor torque after the shift to the second shift stage, with respect to the motor. Correction that outputs a torque command added in the direction to reduce the difference ,
A shift control apparatus for an electric vehicle, characterized in that a shift correction process is performed by selecting . A charge amount detecting means for detecting a charge amount of a battery that supplies power to the motor;
2. The shift control apparatus for an electric vehicle according to claim 1 , wherein the vehicle state in the correction process of the shift control means includes an engagement state of the friction engagement element and a battery charge amount . Battery temperature detection means for detecting the temperature of the battery;
The shift control apparatus for an electric vehicle according to claim 1 or 2 , wherein the engagement state of the friction engagement element and the battery temperature are included as a vehicle state in the correction process of the shift control means. An oil temperature detecting means for detecting a temperature of a hydraulic system for driving the frictional engagement element;
4. The electric vehicle according to claim 1, wherein the vehicle state in the correction process of the shift control means includes an engagement state of the friction engagement element and an oil temperature. 5. Shift control device.

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