JP5691564B2 - Control device for electric vehicle - Google Patents

Description

  The present invention relates to a control device for an electric vehicle including an electric motor that performs rotation speed control and torque control in a driving source for traveling.

2. Description of the Related Art Conventionally, there is known a drive control device for a hybrid vehicle that includes an electric motor that performs rotational speed control and torque control in a travel drive source, and that performs control for switching between rotational speed control and torque control according to a traveling situation or a vehicle situation. (For example, refer to Patent Document 1).
In this conventional apparatus, when the control of the electric motor is switched from the rotational speed control to the torque control, if a difference occurs between the final motor output torque of the rotational speed control and the target motor torque at the start of the torque control, a predetermined change rate is applied. Thus, control for changing the motor torque is performed.

JP-A-10-174209

  However, in the conventional apparatus, when the motor control is switched, the torque change rate of the motor torque is given by a constant value. For this reason, if the torque change rate is given by a large value so as to ensure the response of the driving force, the torsional vibration shock of the powertrain system deteriorates when the motor control is switched after the downshift to the low gear stage during coast deceleration. To do. On the other hand, if the torque change rate is given by a small value that prevents torsional vibration shock, the response of the driving force is deteriorated when the motor control is switched after the downshift when the accelerator is depressed. Therefore, when the torque change rate is given as a constant value, the torque change rate is set to an intermediate value between the two values greatly deviated. For this reason, both the torsional vibration shock and the driving force response are compromised, and there is a problem that the driving force response cannot be ensured at the time of drive down shift and the torsional vibration shock cannot be reduced at the coast down shift. It was.

  The present invention has been made paying attention to the above problem, and corresponds to a traveling scene determined by the accelerator operation and the shift type of the automatic transmission when the electric motor is switched from the rotational speed control to the torque control. Another object of the present invention is to provide an electric vehicle control apparatus capable of achieving different required performance.

In order to achieve the above object, a control device for an electric vehicle according to the present invention includes an electric motor, motor control switching means, an automatic transmission, torque change rate selection processing means, and motor torque change processing means. It was.
The electric motor is provided in a travel drive source.
The motor control switching means switches the control of the electric motor between rotation speed control with a control target as a target motor rotation speed and torque control with a control target as a target motor torque.
The automatic transmission is interposed between the electric motor and drive wheels, and automatically changes the gear ratio according to the vehicle state.
When the switching start condition for switching the electric motor control from the rotational speed control to the torque control is satisfied, the torque change rate selection processing means determines the driving scene determined by the accelerator operation and the shift type of the automatic transmission as a driving force. A torque change rate with a larger value is selected for a travel scene that requires a response, and a torque change rate with a smaller value is selected for a travel scene that requires torsional vibration shock reduction .
When the motor torque change processing means switches the control of the electric motor from the rotational speed control to the torque control, the motor torque difference between the final motor output torque of the rotational speed control and the target motor torque at the start of the torque control is selected. Connection is made by a target motor torque that changes at the torque change rate.

Therefore, when the switching start condition for switching the electric motor control from the rotational speed control to the torque control is satisfied, the traveling scene determined by the accelerator operation and the shift type of the automatic transmission is a traveling scene that requires a driving force response. A torque change rate with a larger value is selected, and a torque change rate with a smaller value is selected for a traveling scene that requires torsional vibration shock reduction. When the electric motor control is switched from the rotational speed control to the torque control, the motor torque difference between the final motor output torque of the rotational speed control and the target motor torque at the start of the torque control changes at the selected torque change rate. Connected by motor torque.
That is, in a powertrain system in which an automatic transmission is arranged at a position downstream of an electric motor, traveling scenes having different required performances are determined by monitoring the accelerator operation and the shift type of the automatic transmission. Different required performances are achieved by selecting a torque change rate suitable for each traveling scene based on the determination of the traveling scene.
For example, in a driving scene of a drive-down shift intervention where the discriminated driving scene may have a large motor torque difference even though the driving force response requirement is high, a torque change rate with a considerably large value can be selected. The driving force response is ensured.
For example, in the traveling scene of coast down shift intervention with high shock sensitivity due to torsional vibration, even though the traveling scene to be discriminated is high, by selecting a torque change rate with a considerably small value, Torsional vibration shock is reduced.
As a result, when the electric motor is switched from the rotational speed control to the torque control, it is possible to achieve different required performance for each traveling scene corresponding to the traveling scene determined by the accelerator operation and the shift type of the automatic transmission.

It is a powertrain block diagram which shows the powertrain of the hybrid vehicle to which the control apparatus of Example 1 was applied. It is a control system block diagram which shows the control system of the hybrid vehicle to which the control apparatus of Example 1 was applied. FIG. 3 is a calculation block diagram illustrating an integrated controller according to the first embodiment. It is a map figure which shows the steady target torque map (a) and MG assist torque map (b) which are used with the control apparatus of Example 1. It is a map figure which shows the engine start stop line map used with the control apparatus of Example 1. FIG. It is a characteristic view which shows the request | requirement power generation output during driving | running | working with respect to battery SOC used with the control apparatus of Example 1. It is a characteristic view which shows the best fuel consumption line of the engine used with the control apparatus of Example 1. FIG. 3 is a shift map diagram illustrating an example of shift lines in the automatic transmission according to the first embodiment. 6 is a time chart illustrating an outline of a motor torque change process when the motor control is switched from the rotational speed control to the torque control in the control device of the first embodiment. 3 is a flowchart illustrating a configuration and a flow of a shift control process executed by a shift control unit of the integrated controller according to the first embodiment. 3 is a flowchart showing the configuration and flow of a rotation speed control and torque control switching process and a motor torque change process executed as a main routine by the motor controller of the first embodiment. 6 is a flowchart showing the configuration and flow of torque change rate selection processing and gear speed corresponding torque change rate selection processing executed as a subroutine when the motor generator is switched from rotational speed control to torque control by the motor controller of the first embodiment. It is a torque change rate characteristic figure which shows the example of a setting of the torque change rate selected according to each driving | running | working scene determined in FIG. Accelerator opening (APO), rotational speed control flag, gear when the motor generator is switched from rotational speed control to torque control in the travel scene of the 3 → 2 drive down shift intervention in the automatic transmission of the control device of the first embodiment It is a time chart which shows each characteristic of stage, rotation, torque, and acceleration. Accelerator opening (APO), rotational speed control flag, gear when the motor generator is switched from rotational speed control to torque control in the travel scene of the 3 → 2 coast down shift intervention in the automatic transmission of the control device of the first embodiment It is a time chart which shows each characteristic of stage, rotation, torque, and acceleration. Accelerator opening (APO), rotational speed control flag, gear when the motor generator is switched from rotational speed control to torque control in a driving scene where the gear ratio is fixed without shifting by the automatic transmission included in the control device of the first embodiment It is a time chart which shows each characteristic of stage, rotation, torque, and acceleration.

  Hereinafter, the best mode for realizing an electric vehicle control apparatus of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
FIG. 1 is a power train configuration diagram illustrating a power train of a hybrid vehicle (an example of an electric vehicle) to which the control device of the first embodiment is applied. Hereinafter, the powertrain configuration will be described with reference to FIG.

  As shown in FIG. 1, the power train system of the hybrid vehicle of the first embodiment includes an engine 1, a motor generator 2 (electric motor; hereinafter referred to as “MG”), and an automatic transmission 3 (hereinafter referred to as “MG”). "AT"), first clutch 4 (hereinafter referred to as "CL1"), second clutch 5 (hereinafter referred to as "CL2"), differential gear 6, and tire 7, 7 (drive wheels). In other words, the engine 1 and 1 motor / 2 clutch are provided in the powertrain system.

  In the engine 1, the engine output shaft and the motor input shaft of the motor generator 2 are connected via a first clutch 4 having a variable torque capacity. In the motor generator 2, a motor output shaft and a transmission input shaft of the automatic transmission 3 are directly connected. In the automatic transmission 3, tires 7 and 7 as driving wheels are connected to a transmission output shaft via a differential gear 6.

  The second clutch 5 selects one frictional engagement element among a plurality of frictional engagement elements by a variable torque capacity clutch / brake that is responsible for power transmission in the transmission depending on the shift state of the automatic transmission 3. It is used as. As a result, the automatic transmission 3 synthesizes the power of the engine 1 input via the first clutch 4 and the power input from the motor generator 2 and outputs them to the tires 7 and 7.

  As the first clutch 4, for example, a dry single plate clutch or a dry multi-plate clutch that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid may be used. As the second clutch 5, for example, a wet multi-plate clutch or a wet multi-plate brake that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid may be used. This powertrain system has two operation modes according to the connection state of the first clutch 4. In the CL1 open state in which the first clutch 4 is disconnected, the EV mode (electric vehicle) travels only with the power of the motor generator 2. Driving mode). On the other hand, the CL1 engagement state in which the first clutch 4 is connected is the HEV mode (hybrid vehicle travel mode) in which the engine 1 and the motor generator 2 travel.

  The power train includes an engine rotation sensor 10 that detects the rotation speed of the engine 1, an MG rotation sensor 11 that detects the rotation speed of the motor generator 2, and an AT input rotation that detects the input shaft rotation speed of the automatic transmission 3. A sensor 12 and an AT output rotation sensor 13 for detecting the output shaft rotation speed of the automatic transmission 3 are provided.

  FIG. 2 is a control system configuration diagram illustrating a hybrid vehicle control system to which the control device of the first embodiment is applied. Hereinafter, the control system configuration will be described with reference to FIG.

  As shown in FIG. 2, the control system of the first embodiment includes an integrated controller 20, an engine controller 21, a motor controller 22, an inverter 8, a battery 9, a solenoid valve 14, a solenoid valve 15, and an accelerator opening. A degree sensor 17, a brake hydraulic pressure sensor 23, and an SOC sensor 16.

  The integrated controller 20 performs integrated control of operating points of the powertrain system. The integrated controller 20 selects an operation mode capable of realizing the driving force desired by the driver according to the accelerator opening APO, the battery charge state SOC, and the vehicle speed VSP (proportional to the automatic transmission output shaft rotation speed). To do. Then, according to the selected operation mode, the target MG torque or the target MG rotation speed is commanded to the motor controller 22, the target engine torque is commanded to the engine controller 21, and the drive signal is commanded to the solenoid valves 14 and 15. .

  The engine controller 21 controls the engine 1. The motor controller 22 controls the motor generator 2. The inverter 8 drives the motor generator 2. The battery 9 stores electrical energy. The solenoid valve 14 controls the hydraulic pressure of the first clutch 4. The solenoid valve 15 controls the hydraulic pressure of the second clutch 5. The accelerator opening sensor 17 detects an accelerator opening (APO). The brake oil pressure sensor 23 detects brake oil pressure (BPS). The SOC sensor 16 detects the charge capacity state of the battery 9.

  FIG. 3 is a calculation block diagram illustrating the integrated controller 20 according to the first embodiment. The configuration of the integrated controller 20 will be described below based on FIG.

  As shown in FIG. 3, the integrated controller 20 includes a target drive torque calculation unit 100, a mode selection unit 200, a target power generation output calculation unit 300, an operating point command unit 400, and a shift control unit 500. ing.

  The target drive torque calculation unit 100 uses the target steady drive torque map shown in FIG. 4 (a) and the MG assist torque map shown in FIG. 4 (b) to calculate the target steady drive from the accelerator opening APO and the vehicle speed VSP. Calculate torque and MG assist torque.

  The mode selection unit 200 calculates an operation mode (HEV mode, EV mode) using the vehicle speed VSP and the accelerator opening APO and the engine start / stop line map shown in FIG. As indicated by the characteristics of the engine start line (SOC high, SOC low) and the engine stop line (SOC high, SOC low), the engine start line and the engine stop line are shown in FIG. Is set as a characteristic that decreases in the direction of decreasing. It should be noted that when the engine is started in the EV mode, the engagement torque of the second clutch 5 is realized so that the slip engagement state can be realized when the operating point by the accelerator opening APO and the vehicle speed VSP exceeds the engine start line shown in FIG. The capacity is controlled to be equivalent to the driver requested driving torque. Then, after determining that the second clutch 5 has started slipping, engagement of the first clutch 4 is started and the engine speed is increased. When the engine speed reaches a speed at which the initial explosion is possible, the engine 1 is burned and the first clutch 4 is completely engaged when the motor speed and the engine speed become close. Thereafter, the second clutch 5 is locked up and transferred to the HEV mode.

  The target power generation output calculation unit 300 calculates a target power generation output from the battery SOC using the traveling power generation request output map shown in FIG. Further, an output necessary for increasing the engine torque from the current operating point to the best fuel consumption line shown in FIG. 7 is calculated, and an output smaller than the target power generation output is added to the engine output as a required output.

  The operating point command unit 400 inputs the accelerator opening APO, the target steady torque, the MG assist torque, the target mode, the vehicle speed VSP, and the required power generation output. Then, using these input information as the operating point reaching target, a transient target engine torque, target MG torque, target CL2 torque capacity, target speed ratio, and CL1 solenoid current command are calculated.

  The shift control unit 500 drives and controls a solenoid valve in the automatic transmission 3 so as to achieve these from the target CL2 torque capacity and the target gear ratio. FIG. 8 shows an example of a shift line map used in the shift control. The shift control determines which gear stage is to be changed from the current gear stage to the next gear stage based on the driving point based on the vehicle speed VSP and the accelerator opening APO and the shift line map. When the operating point crosses the upshift line (solid line in FIG. 8) or the downshift line (dotted line in FIG. 8) of the shift line map, an upshift request or a downshift request is issued, and the automatic transmission 3 corresponding to the shift request. The frictional engagement element is engaged / released to change the speed. In the first embodiment, the gear ratio change in the inertia phase region is changed by adding the rotation speed control by the motor generator 2 provided on the input side of the automatic transmission 3 at the time of shifting, as compared with the shift control only by the hydraulic control. Shifting control is performed smoothly.

  FIG. 9 shows an overview of the motor torque change process when the motor control is switched from the rotational speed control to the torque control in the control device of the first embodiment. The outline of the motor torque change process will be described below with reference to FIG.

When the control of the motor generator 2 is switched from the rotational speed control to the torque control, a torque change rate suitable for the traveling scene determined by the accelerator operation and the state monitoring of the automatic transmission 3 is selected.
Here, the traveling scene determined by monitoring the state of the automatic transmission 3 refers to the type of shift in the automatic transmission 3 (down shift or up shift by drive / coast, etc.) and the type of shift stage (first speed, A traveling scene determined by monitoring the second speed, the third speed, and the like.

Then, as shown in the frame of FIG. 9, the target motor torque at which the motor torque difference between the final motor output torque of the rotational speed control and the target motor torque (final) at the start of torque control changes at the selected torque change rate. Connected by
For example, when the travel scene to be discriminated is a travel scene of a drive-down shift intervention in which the motor torque difference may be large even though the driving force response request is high, the torque change rate A with a considerably large value is selected. Is done.
For example, if the travel scene to be discriminated is a coast scene where a shock sensitivity due to torsional vibration is high even though the torsional vibration shock reduction requirement is high, a torque change rate B with a considerably small value is selected. The
For example, when the determined travel scene is a travel scene other than the drive down shift or the coast down shift, the torque change rate C based on an intermediate value is selected.

  FIG. 10 shows the configuration and flow of a shift control process executed by the shift control unit 500 of the integrated controller 20 of the first embodiment. Hereinafter, each step of FIG. 10 will be described.

  In step S1, it is determined whether the current gear stage and the next gear stage are different, and whether or not a shift from the current gear stage to the next gear stage is started or a shift is in progress. If YES (shift start or shifting), the process proceeds to step S2, and if NO (gear stage fixed), the process proceeds to step S8.

In step S2, following the determination that shifting is being started or shifting is being performed in step S1, a release command is output to the release clutch during shifting, and the process proceeds to step S3.
Here, the speed change is performed by changing the clutch in which one of the two clutches involved in the speed change at that time is released and the other clutch is engaged. The open side clutch at the time of clutch change is referred to as “shift open clutch”, and the engagement side clutch is referred to as “shift engagement clutch”.

In step S3, following the release command output to the release clutch at the time of shifting in step S2, the slip determination is established (the difference between the input rotation speed and the output rotation speed of the automatic transmission 3 can be determined as surely clutch slipping. It is determined whether or not the rotation difference threshold is reached. If YES (slip determination is established), the process proceeds to step S4. If NO (slip determination is not established), the process proceeds to return.
Here, the shift control is performed after the shift start phase → the torque phase → the inertia phase → the shift end phase, but when the inertia phase starts, there is a difference between the input rotation speed and the output rotation speed of the automatic transmission 3. Arise. Therefore, in other words, this slip determination can be referred to as an inertia phase start determination that has entered the inertia phase region.

  In step S4, following the determination that the slip determination is established in step S3, the rotation speed control flag is rewritten from the rotation speed control flag = 0 (torque control) to the rotation speed control flag = 1 (rotation speed control). Proceed to step S5.

  In step S5, following rewriting to the rotation speed control flag = 1 in step S4, an engagement command is output to the shifting engagement clutch, and the process proceeds to step S6.

In step S6, following the engagement command output to the engagement clutch at the time of shifting in step S5, it is determined whether the rotation speed control flag = 0 (step S25 in FIG. 11) and whether the shifting process is completed. If YES (shift end condition is satisfied), the process proceeds to step S7, and if NO (shift end condition is not satisfied), the process proceeds to return.
Here, the end of the shift process means, for example, when the release clutch at the time of shift is completely opened and the hydraulic pressure of the engagement clutch at the time of shift becomes a predetermined value or more.

  In step S7, following the determination that the shift end condition is satisfied in step S6, the shift is ended and the process proceeds to RETURN.

In step S8, following the determination that the gear position is fixed in step S1, it is determined whether or not there is a slip request for the second clutch 5. If YES (CL2 slip is requested), the process proceeds to step S9. If NO (CL2 slip is not requested), the process proceeds to RETURN.
Here, during traveling with the gear fixed, for example, when there is an engine start request or an engine stop request, the second clutch 5 is required to be slip-engaged in order to prevent the occurrence of an engine start shock or an engine stop shock. Is done.

In step S9, following the determination that there is a CL2 slip request in step S8, the rotation speed control flag is rewritten from the rotation speed control flag = 0 (torque control) to the rotation speed control flag = 1 (rotation speed control), and the return. Proceed to
That is, the slip engagement state of the second clutch 5 is ensured by executing the rotational speed control of the motor generator 2 with the rotational speed exceeding the clutch output rotational speed as the target clutch input rotational speed in response to the CL2 slip request.

  FIG. 11 shows the configuration and flow of the rotational speed control and torque control switching process and the motor torque change process executed as the main routine by the motor controller 22 of the first embodiment (motor control switching means, motor torque change processing means). ). Hereinafter, each step of FIG. 11 will be described.

In step S20, it is determined whether or not the rotation speed control flag = 1. If YES (rotational speed control flag = 1), the process proceeds to step S21. If NO (rotational speed control flag = 0), the process proceeds to step S26.
That is, YES is determined if the engine speed control flag is rewritten to 1 in step S4 or step S9 of FIG. 10 showing the shift control process, and NO if the engine speed control flag is rewritten to 0 in step S25 described later. To be judged.

  In step S21, following the determination that the rotational speed control flag = 1 in step S20, the target engine realized by the engine 1 according to the shift mode determined by the current gear stage and the next gear stage, or the fixed gear stage. Torque is calculated, and the process proceeds to step S22.

In step S22, following the calculation of the target engine torque in step S21, the target MG rotation speed realized by the motor generator 2 is calculated according to the shift mode determined by the current gear stage and the next gear stage or the fixed gear stage. The process proceeds to step S23.
Here, in the case of upshifting, the target MG rotation speed, which is the target value for rotation speed control, gradually decreases from the transmission input rotation speed at the current gear stage to the transmission input rotation speed at the next gear stage. Calculated. On the other hand, in the case of a downshift, the speed is calculated so as to gradually increase from the transmission input rotational speed at the current gear stage to the transmission input rotational speed at the next gear stage. Further, in the case of an engine start request or an engine stop request, the number of rotations is set to ensure the slip engagement state of the second clutch 5.

  In step S23, following the target MG rotation speed calculation in step S22, the motor torque is calculated so as to follow the target MG rotation speed, and the process proceeds to step S24.

In step S24, following the calculation of the motor torque in step S23, it is determined whether or not the rotation speed control end condition is satisfied. If YES (revolution speed control end condition is satisfied), the process proceeds to step S25, and if NO (revolution speed control end condition is not satisfied), the process proceeds to return.
Here, when the speed control end condition is satisfied, in the case of a shift, it is determined that the difference between the transmission input speed and the transmission output speed determined by the gear ratio at the next gear stage after the shift is locked up. The time when the rotation difference is possible. In other words, the transmission input rotation speed converges to the transmission input rotation speed of the next gear stage after the shift, and it is determined that the inertia phase has exited from the inertia phase area. Further, in the case of an engine start request or an engine stop request, it means when the CL2 slip is out of the required area or when a set time has elapsed.

  In step S25, following the determination that the rotation speed control end condition is satisfied in step S24, the rotation speed control flag is changed from rotation speed control flag = 1 (rotation speed control) to rotation speed control flag = 0 (torque control). And proceed to return.

  In step S26, following the determination that the rotation speed control flag = 0 in step S20, a target engine torque and a target motor torque, which are target values for torque control, are calculated, and the process proceeds to step S27.

  In step S27, following the calculation of the target engine torque / target motor torque in step S26, is the previous value of the rotational speed control flag the rotational speed control flag = 1 and whether the current value is the rotational speed control flag = 0? NO, that is, whether or not the condition for starting the switching from the rotational speed control to the torque control is satisfied. If YES (switching start condition is satisfied), the process proceeds to step S28. If NO (switching start condition is not satisfied), the process proceeds to step S29.

  In step S28, following the determination that the switching start condition is satisfied in step S27, the torque change rate selection process and the shift speed corresponding torque change rate selection process are executed according to the flowchart of the subroutine of FIG. 12, and the process proceeds to step S30. move on.

  In step S29, following the determination that the switching start condition is not satisfied in step S27, the motor output torque (which has been increased by the motor torque change process from the final motor output torque at the time of switching from the rotational speed control to the torque control) ( It is determined whether or not the actual motor torque has reached the target motor torque (final) calculated in step S26. If YES (reached target motor torque), the process proceeds to return, and if NO (not reached target motor torque), the process proceeds to step S30.

  In step S30, following the torque change rate selection process in step S28 or the determination that the target motor torque has not been reached in step S29, the target motor in torque control is switched when switching from rotational speed control to torque control. A motor torque change process is performed to connect the difference between the torque and the final motor output torque at the end of the rotation speed control by the torque change rate selected in step S28, and the process proceeds to return.

  FIG. 12 shows the configuration and flow of a torque change rate selection process and a gear change rate corresponding torque change rate selection process that are executed as a subroutine when the motor controller 22 of the first embodiment switches the motor generator 2 from rotation speed control to torque control. (Motor torque change processing means, gear speed change motor torque change processing means). Hereinafter, each step of FIG. 12 will be described.

  In step S281, it is determined whether or not it is a drive-down shift by depression of the accelerator. If YES (drive down shift), the process proceeds to step S282. If NO (other than drive down shift), the process proceeds to step S283.

In step S282, following the determination of the drive down shift in step S281, the torque change rate during the drive down shift is selected, and the process proceeds to the end.
Here, as shown in FIG. 13, the torque change rate at the time of drive-down shift is set to a large value that matches the required driving force response and has the highest torque change gradient with respect to time.

  In step S283, following the determination that it is other than the drive down shift in step S281, it is determined whether or not the coast down shift is due to the release of the accelerator pedal. If YES (coast down shift), the process proceeds to step S284. If NO (other than the coast down shift), the process proceeds to step S285.

In step S284, following the determination of the coast down shift in step S283, the torque change rate during the coast down shift is selected, and the process proceeds to the end.
Here, as shown in FIG. 13, the torque change rate at the time of the coast down shift is set to the smallest value with which the change gradient of the torque with respect to time is adapted to the required torsional vibration shock reduction. Note that the torque change rate during coast downshifting is maintained at a small value until a predetermined time, but when the time exceeds the predetermined time, the torque change rate is set to a larger value so as to respond to the request for reducing the torsional vibration shock while ensuring the response It is set according to the broken line characteristics.

In step S285, following the determination that it is other than the coast down shift in step S283, of the torque change rate set for each shift stage, the shift stage selected at the start of switching from the rotational speed control to the torque control is selected. Select the torque change rate and go to the end.
Here, the torque change rate when one of the plurality of shift speeds is selected is set for each shift speed, as shown in FIG. 13, and is based on the torque change rate during the normal shift. The torque change rate at the time of drive down shift and the torque change rate at the time of coast down shift are set. A larger value is set as the shift stage is on the deceleration side (first speed side), and a smaller value is set as the shift stage is at a constant speed (fifth speed) or an increase side (seventh speed side).

Next, the operation will be described.
First, “the problem of the comparative example” will be described. Subsequently, the functions of the hybrid vehicle control apparatus of the first embodiment are “motor control switching action”, “motor torque change processing action at the time of drive-down shift intervention”, and “motor torque change processing action at the time of coast-down shift intervention”. , “Motor torque change processing action when no shift is intervening” will be described separately.

[Problems of comparative example]
For example, when the motor control is switched, the torque change rate is given by one large value that secures a driving force response with respect to a large motor torque difference that occurs after a drive down shift with the accelerator being depressed. In this case, although the change rate is suitable for the drive down shift, the change rate is too large for the coast down shift, and the torque change gradient connecting the motor torque differences becomes steep. For this reason, when switching from rotational speed control after downshifting to a low gear stage during coast deceleration to torque control, a torsional vibration shock of a powertrain system such as a propeller shaft is likely to occur.

  On the other hand, when the motor control is switched, the torque change rate is given by one small value that suppresses the occurrence of a torsional vibration shock with respect to the motor torque difference generated after the downshift during coast deceleration. In this case, although the change rate is suitable for the coast down shift, the change rate is too small for the drive down shift, and the torque change gradient connecting the motor torque differences becomes gentle. For this reason, a driving force response cannot be ensured with respect to a large motor torque difference generated after a drive-down shift due to depression of the accelerator.

  Therefore, when switching the motor control, when a single value is given as the rate of change in torque, it becomes an intermediate value between a large value that secures the driving force response and a small value that reduces the torsional vibration shock. What gives this intermediate value as a torque change rate is a comparative example.

  In the case of this comparative example, when changing from rotational speed control to torque control, the rate of change is given by one intermediate value, so the drive force response required by the driver for the occurrence of a large motor torque difference at the time of drive down shift is obtained. It does not lead to securing. On the other hand, at the time of coast downshift, it is not possible to reduce the torsional vibration shock of the powertrain system in a coast state with high shock sensitivity.

  As described above, in the case of the comparative example, the motor torque difference is connected by one intermediate torque change rate, and the setting of the torque change rate is set to generate a large motor torque difference at the time of drive down shift or at the time of coast down shift. It is a compromise value setting that does not consider high shock sensitivity. For this reason, the two required performances of securing the driving force response and reducing the torsional vibration shock cannot be satisfied at the same time. Result.

[Motor control switching action]
As described above, the present technology relates to how the motor torque difference is connected when the motor control is switched from the rotational speed control to the torque control. Hereinafter, the premise motor control switching action will be described.

First, when there is a shift intervention, while the inertia phase is not started and the slip determination is not established, the flow of step S1 → step S2 → step S3 → return is repeated in the flowchart of FIG. In other words, as the speed change operation, in step S2, a release command is only output to the speed release clutch.
When the slip determination is established by starting the inertia phase, the flow of step S1, step S2, step S3, step S4, step S5, step S6, and return is repeated in the flowchart of FIG. That is, when the start of the inertia phase is determined, in step S4, the rotation speed control flag is rewritten from 0 to 1, and the torque control is switched to the rotation speed control.
Further, in steps S2 and S5, the shift is advanced by outputting a command to the release clutch at the time of shifting and the engagement clutch at the time of shifting.
When the shift end condition is satisfied, in the flowchart of FIG. 10, the process proceeds in the order of step S1, step S2, step S3, step S4, step S5, step S6, step S7, and return, and the shift is terminated in step S7.

  When there is no shift intervention, while there is no CL2 slip request, the flow of step S1 → step S8 → return is repeated in the flowchart of FIG. However, if there is a CL2 slip request due to an engine start request or the like, in the flowchart of FIG. 10, the process proceeds from step S1 to step S8 to step S9 to return, and in step S9, the rotation speed control flag is rewritten from 0 to 1, Switching from torque control to rotational speed control is possible.

  Then, when the rotational speed control flag is rewritten from 0 to 1 in step S4 or step S9 of the shift control process of FIG. 10, in the flowchart of FIG. 11, step S20 → step S21 → step S22 → step S23 → step S24 → The flow to return is repeated. That is, the rotational speed control using the target value as the target MG rotational speed is continued until the rotational speed control end condition is satisfied in step S24.

  If the rotation speed control end condition is satisfied in step S24 regardless of whether or not there is a shift intervention, the process proceeds from step S24 to step S25 to return in the flowchart of FIG. That is, when the end of the inertia phase is determined, the rotation speed control flag is rewritten from 1 to 0 in step S25. From the next control cycle, the process proceeds from step S20 to step S26 and subsequent steps in the flowchart of FIG. 11, and the control is switched from the rotational speed control to the torque control with the motor torque change process interposed therebetween.

  As described above, switching from the rotational speed control to the torque control is performed regardless of whether or not there is a shift intervention. At this time, a torque change rate suitable for the traveling scene determined by monitoring the state of the automatic transmission 3 is selected. When a target motor torque in torque control and a motor torque difference at the end of the rotational speed control are generated, a motor torque change process is performed in which the motor torque difference is connected by a selected torque change rate.

[Motor torque change processing action during drive-down shift intervention]
In order to solve the problem of the comparative example described above, it is necessary to ensure a driving force response at the time of drive down shift intervention. Hereinafter, the motor torque change processing operation at the time of the drive down shift intervention reflecting this will be described.

  When the control of the motor generator 2 is switched from the rotational speed control to the torque control, the first control cycle proceeds to step S20 → step S26 → step S27 → step S28 in the flowchart of FIG. A change rate selection process is performed. At this time, when the type of shift is a drive-down shift by depressing the accelerator, the process proceeds from step S281 to step S282 to end in the flowchart of FIG. 12, and in step S282, a torque change rate at the time of drive-down shift is selected. .

And it progresses from step S28 of FIG. 11 to step S30-> return, and the flow which progresses from step S20-> step S26-> step S27-> step S29-> step S30-> return is repeated from the next control period. That is, in step S30, a motor torque change process is performed in which the difference between the target motor torque in the torque control and the final motor output torque at the end of the rotational speed control is connected by the torque change rate at the time of drive down shift selected in step S28. Done.
Therefore, at the time of drive-down shift, which may result in a large motor torque difference, the driving force from the rotational speed control to the torque control is met by responding to the driving force response request and connecting the large motor torque difference by the steep torque change rate. Response is secured.

Hereinafter, the motor torque change processing operation at the time of drive-down gear shift intervention will be described using the time chart of FIG. 14 showing each characteristic when the motor generator 2 is switched from the rotation speed control to the torque control at the time of 3 → 2 drive-down gear shift intervention. To do.
In FIG. 14, time t1 indicates the start of accelerator depression. Time t2 indicates the end of accelerator depression. Time t3 indicates when a downshift is requested from the third speed to the second speed. Time t4 indicates when switching from torque control to rotational speed control. Time t5 indicates when switching from the rotational speed control to the torque control. Time t6 indicates the end of the motor torque change process in the first embodiment. Time t7 indicates the end of the motor torque change process in the comparative example.

  At the time of the 3 → 2 drive down shift intervention, when switching from the rotational speed control to the torque control, a large motor torque difference from the negative motor torque to the positive target torque is obtained. At this time, as shown in the comparative example, when the motor torque change process is performed with the change rate based on the intermediate value, the motor torque characteristic indicated by the thin solid line in FIG. Are connected by a torque change rate of a gentle gradient. That is, as shown in the acceleration characteristic by the dotted line in FIG. 14, the inclination of the motor torque is gradual, the switching time lag is large, and the required driving force response cannot be met.

  On the other hand, when the motor torque change process is performed at a torque change rate suitable for the drive-down shift as in the first embodiment, the thick solid line in FIG. 14 extends from the switching time t5 to the time t6 when the target motor torque is reached. As shown in the motor torque characteristics, connection is made by a steep torque change rate. That is, as shown in the acceleration characteristic by the solid line in FIG. 14, the inclination of the motor torque becomes steep, the switching time lag becomes small, and the required driving force response can be met.

As described above, in the first embodiment, when the travel scene to be discriminated is a travel scene due to a drive down shift intervention by depressing the accelerator, the torque change rate to be selected is set to a large value that matches the required driving force response. A configuration to set was adopted.
With this configuration, when the control of the motor generator 2 is switched from the rotational speed control to the torque control, a large motor torque difference between the rotational speed control and the torque control is caused by the steep torque due to the torque change rate during the selected drive down shift. Connected.
Therefore, when the motor generator 2 is switched from the rotational speed control to the torque control during the drive down shift intervention, the required driving force response is ensured regardless of the occurrence of a large motor torque difference.

[Motor torque change processing action during coast down shift]
In order to solve the problem of the comparative example, it is necessary to reduce the torsional vibration shock during the coast down shift intervention. Hereinafter, the motor torque change processing operation at the time of the coast downshift intervention reflecting this will be described.

  When the control of the motor generator 2 is switched from the rotational speed control to the torque control, the first control cycle proceeds to step S20 → step S26 → step S27 → step S28 in the flowchart of FIG. A change rate selection process is performed. At this time, when the type of shift is coast down shift by releasing the accelerator pedal, in the flowchart of FIG. 12, the process proceeds from step S281 to step S283 to step S284 to end, and in step S284, the torque change rate at the coast down shift Is selected.

And it progresses from step S28 of FIG. 11 to step S30-> return, and the flow which progresses from step S20-> step S26-> step S27-> step S29-> step S30-> return is repeated from the next control period. That is, in step S30, a motor torque change process is performed in which the difference between the target motor torque in the torque control and the final motor output torque at the end of the rotation speed control is connected by the torque change rate at the coast down shift selected in step S28. Done.
Therefore, during coast downshifts with high shock sensitivity, the torsional vibration shock is reduced when switching from rotational speed control to torque control by responding to the request for reduction of torsional vibration shock and connecting the motor torque difference with the torque change rate of a gentle gradient. Is done.

Hereinafter, the motor torque change processing operation at the time of coast down shift intervention will be described with reference to the time chart of FIG. 15 showing each characteristic when the motor generator 2 is switched from rotation speed control to torque control at the time of 3 → 2 coast down shift intervention. To do.
In FIG. 15, time t1 indicates the time when the accelerator release starts. Time t2 indicates the time when the accelerator is released. Time t3 indicates when a downshift is requested from the third speed to the second speed. Time t4 indicates when switching from torque control to rotational speed control. Time t5 indicates when switching from the rotational speed control to the torque control. Time t6 indicates the end of the motor torque change process in the comparative example. Time t7 indicates the end of the motor torque change process in the first embodiment.

  At the time of 3 → 2 drive down shift intervention, when switching from the rotational speed control to the torque control, a small motor torque difference from the negative motor torque to the negative target torque is obtained. At this time, as shown in the comparative example, when the motor torque change process is performed with the change rate based on the intermediate value, the motor torque characteristic indicated by the thin solid line in FIG. And a steep torque change rate. In other words, as shown by the acceleration characteristics by the dotted line in FIG. 15, the motor torque has a steep inclination, the acceleration fluctuation becomes large, and the required torsional vibration shock cannot be reduced.

  On the other hand, when the motor torque change process is performed at the torque change rate suitable for the coast down shift as in the first embodiment, the bold solid line in FIG. 15 extends from the switching time t5 to the time t7 when the target motor torque is reached. As shown in the motor torque characteristics, the torque change rate is fairly gentle. That is, as shown by the acceleration characteristic by the solid line in FIG. 15, the inclination of the motor torque becomes gentle, the acceleration fluctuation becomes small, and the demand for reduction of torsional vibration shock can be met.

As described above, in the first embodiment, when the travel scene to be determined is a travel scene due to a coast downshift intervention by releasing the accelerator pedal, the torque change rate to be selected is a large value that matches the required torsional vibration shock. The configuration set to is adopted.
With this configuration, when the control of the motor generator 2 is switched from the rotational speed control to the torque control, the motor torque difference between the rotational speed control and the torque control is connected by a gentle gradient torque based on the selected torque change rate during the coast down shift. It is.
Therefore, when the motor generator 2 is switched from the rotation speed control to the torque control during the coast downshift intervention, the required reduction of the torsional vibration shock is achieved despite the coast deceleration with high shock sensitivity.

[Motor torque change processing action when shift is not involved]
When gear shift is not involved, the gear is fixed at a certain gear, but the gear ratio (torque sharing ratio) is different at each gear. Therefore, if the torque change rate is given as a constant value, the driving force response and torsional vibration shock deteriorate. There is a need to avoid these well. Hereinafter, the motor torque change processing operation when a shift reflecting this will not intervene will be described.

  When the control of the motor generator 2 is switched from the rotational speed control to the torque control, the first control cycle proceeds to step S20 → step S26 → step S27 → step S28 in the flowchart of FIG. A change rate selection process is performed. At this time, if the type of shift is neither drive-down shift nor coast-down shift, the process proceeds from step S281 to step S283 to step S285 to end in the flowchart of FIG. 12, and in step S285, the torque set for each shift stage. From the change rate, the torque change rate of the gear stage at that time is selected.

And it progresses from step S28 of FIG. 11 to step S30-> return, and the flow which progresses from step S20-> step S26-> step S27-> step S29-> step S30-> return is repeated from the next control period. That is, in step S30, a motor torque change process is performed in which the difference between the target motor torque in the torque control and the final motor output torque at the end of the rotation speed control is connected by the torque change rate corresponding to the gear selected in step S28. Is called.
Therefore, when a shift stage on the underdrive side with a high driving force response requirement is selected, the driving force response is ensured when the motor control is switched by connecting with the torque change rate on the steep slope side that meets the requirement. . On the other hand, when the overdrive side gear position with high shock sensitivity is selected, the torsional vibration shock is reduced when the motor control is switched by connecting with the torque change rate on the gentle slope side that meets the requirements.

Hereinafter, using the time chart of FIG. 16 representing each characteristic when the motor generator 2 is switched from the rotational speed control to the torque control when the third speed is fixed and the shift is not involved, the motor torque change processing operation when the shift is not intervened is shown. explain.
In FIG. 16, time t1 indicates the start of acceleration decrease. Time t2 indicates the time when the acceleration has shifted to the deceleration side. Time t3 indicates when the target rotational speed starts to rise. Time t4 indicates when switching from torque control to rotational speed control. Time t5 indicates when switching from the rotational speed control to the torque control. Time t6 indicates the end of the motor torque change process in the comparative example. Time t7 indicates the end of the motor torque change process in the first embodiment.

  During deceleration at which the third speed is fixed and shift is not involved, a small motor torque difference from a negative motor torque to a negative target torque is obtained when switching from rotational speed control to torque control. At this time, as shown in the comparative example, when the motor torque change process is performed with the change rate based on the intermediate value, the motor torque characteristic indicated by the thin solid line in FIG. And a steep torque change rate. That is, as shown in the acceleration characteristic by the dotted line in FIG. 16, the motor torque has a steep inclination, the acceleration fluctuation becomes large, and the required torsional vibration shock cannot be reduced.

  On the other hand, when the motor torque change process is performed at a torque change rate suitable for the gear position (3rd speed) as in the first embodiment, the time shown in FIG. As shown by the thick solid line motor torque characteristics, the torque change rate is more moderate than the intermediate value. That is, as shown by the acceleration characteristics by the solid line in FIG. 16, the inclination of the motor torque becomes gentle, the acceleration fluctuation becomes small, and the demand for reduction of torsional vibration shock can be met.

As described above, in the first embodiment, the torque change rate is set for each gear position when the traveling scene is based on selection of one gear speed among a plurality of gear speeds. A configuration was adopted in which the larger the gear position is, the lower the gear ratio is, and the smaller the gear position is, the higher the gear ratio is.
With this configuration, when the control of the motor generator 2 is switched from the rotational speed control to the torque control, the motor torque difference between the rotational speed control and the torque control is connected by the gradient torque based on the torque change rate selected according to the shift speed. .
Therefore, when the motor generator 2 is switched from the rotational speed control to the torque control when the shift is not involved, the driving force response required at the low gear ratio is ensured, and the torsional vibration shock required at the high gear ratio is reduced. Achieved.

Next, the effect will be described.
In the hybrid vehicle control device of the first embodiment, the following effects can be obtained.

(1) an electric motor (motor generator 2) provided in the driving source for traveling;
Motor control switching means for switching the control of the electric motor (motor generator 2) between rotation speed control with the control target as the target motor rotation speed and torque control with the control target as the target motor torque (FIG. 10). When,
An automatic transmission 3 interposed between the electric motor (motor generator 2) and drive wheels (tires 7 and 7), and automatically changes the gear ratio according to the vehicle state;
When the control of the electric motor (motor generator 2) is switched from rotational speed control to torque control, the travel scene determined by the accelerator operation and the shift type of the automatic transmission 3 is a travel scene that requires a driving force response. Select a torque change rate with a larger value as much as possible, select a torque change rate with a smaller value as the driving scene requires shock reduction, and select the final motor output torque for rotational speed control and the target motor torque at the start of torque control. Motor torque change processing means (FIGS. 11 and 12) for connecting the motor torque difference of the motor torque difference by the target motor torque that changes at the torque change rate;
Is provided.
For this reason, when the electric motor (motor generator 2) is switched from the rotational speed control to the torque control, it corresponds to the travel scene determined by the accelerator operation and the shift type of the automatic transmission 3, and achieves different required performance for each travel scene. You can. In other words, in a driving scene where a driving force response is required, a driving force response can be ensured in response to the request, and in a driving scene where a shock reduction is required, a torsional vibration shock can be reduced in response to the request.

(2) The motor torque change processing means (FIGS. 11 and 12), when the determined travel scene is a travel scene of a drive-down shift intervention by depressing an accelerator, determines the torque change rate as the required drive. A large value that matches the force response is set (step S282, FIG. 13).
For this reason, in addition to the effect of (1) above, when the electric motor (motor generator 2) is switched from the rotational speed control to the torque control at the time of the drive down shift intervention, the required driving force regardless of the occurrence of a large motor torque difference. A response can be secured.

(3) The motor torque change processing means (FIGS. 11 and 12) is required for the torque change rate when the determined travel scene is a travel scene of a coast downshift intervention by releasing the accelerator pedal. A small value suitable for shock reduction is set (step S284, FIG. 13).
For this reason, in addition to the effects (1) and (2) above, when the electric motor (motor generator 2) is switched from the rotation speed control to the torque control during the coast downshift intervention, the coast deceleration with high shock sensitivity is also being performed. Regardless, the required torsional vibration shock reduction can be achieved.

(4) The automatic transmission 4 is a stepped transmission that automatically changes a plurality of shift stages having different gear ratios according to a vehicle state.
When the driving scene is selected by selecting one of the plurality of shift speeds, the torque change rate is set for each shift speed, and is set to a larger value as the shift speed is on the deceleration side. Shift speed corresponding motor torque change processing means for setting a smaller value as the speed is on the constant speed or higher speed side is provided (step S285, FIG. 13).
For this reason, in addition to the effects (1) to (3) above, when the electric motor (motor generator 2) is switched from the rotational speed control to the torque control when no shift is intervening, the driving force response required at the low gear ratio is required. The torsional vibration shock required at the high gear ratio can be reduced.

  As mentioned above, although the control apparatus of the electric vehicle of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, an example of a stepped automatic transmission 3 having a plurality of shift stages is shown as an automatic transmission. However, the automatic transmission may be an example of a continuously variable transmission such as a belt type continuously variable transmission or a toroidal type continuously variable transmission that continuously controls the gear ratio. Further, when the automatic transmission is a continuously variable transmission, the torque change rate may be set according to the target speed ratio and the target input rotational speed when the target speed ratio and the target input rotational speed are fixed.

  In the first embodiment, an example is shown in which the second clutch CL2 is selected from the friction elements incorporated in the stepped automatic transmission AT. However, the second clutch CL2 may be provided separately from the automatic transmission AT. For example, the second clutch CL2 may be provided separately from the automatic transmission AT between the motor / generator MG and the transmission input shaft. An example in which the second clutch CL2 is provided separately from the automatic transmission AT between the transmission output shaft and the drive wheels is also included.

  In the first embodiment, the example in which the first clutch 4 is used as the mode switching means for switching between the HEV mode and the EV mode has been described. However, as the mode switching means for switching between the HEV mode and the EV mode, for example, a differential device or a power split device that exhibits a clutch function without using a clutch, such as a planetary gear, may be used.

  In Example 1, the example which applied the control apparatus of this invention with respect to the hybrid vehicle was shown. However, the present invention can also be applied to other electric vehicles such as an electric vehicle and a fuel cell vehicle having a motor generator as a driving source for traveling. Of course, the present invention can also be applied to a hybrid vehicle using a drive system other than the one-motor / two-clutch hybrid vehicle shown in the first embodiment.

1 Engine 2 Motor generator (electric motor)
3 Automatic Transmission 4 First Clutch 5 Second Clutch 6 Differential Gear 7 Tire (Drive Wheel)
8 Inverter 9 Battery 10 Engine rotation sensor 11 MG rotation sensor 12 AT input rotation sensor 13 AT output rotation sensor 14, 15 Solenoid valve 16 SOC sensor 17 Accelerator opening sensor 20 Integrated controller 21 Engine controller 22 Motor controller 23 Brake hydraulic pressure sensor

Claims (4)

An electric motor provided in the driving source for traveling;
Motor control switching means for switching the control of the electric motor between rotation speed control with a control target as a target motor rotation speed and torque control with a control target as a target motor torque;
An automatic transmission that is interposed between the electric motor and the drive wheels and automatically changes a gear ratio according to a vehicle state;
When a switching start condition for switching the electric motor control from rotational speed control to torque control is satisfied, the traveling scene determined by the accelerator operation and the shift type of the automatic transmission is a traveling scene in which a driving force response is required. A torque change rate selection processing means for selecting a torque change rate with a larger value and selecting a torque change rate with a smaller value as the driving scene requires torsional vibration shock reduction;
When the control of the electric motor is switched from rotational speed control to torque control, the motor torque difference between the final motor output torque of rotational speed control and the target motor torque at the start of torque control is changed at the selected torque change rate. Motor torque change processing means connected by motor torque;
An electric vehicle control device comprising: In the control device of the electric vehicle according to claim 1,
The torque change rate selection processing means sets the torque change rate to a large value suitable for a required driving force response when the determined travel scene is a travel scene of a drive down shift intervention by depression of an accelerator. A control device for an electric vehicle. In the control apparatus for the electric vehicle according to claim 1 or 2,
The torque change rate selection processing means sets the torque change rate to a small value suitable for a required shock reduction when the determined travel scene is a travel scene of coast down shift intervention by releasing an accelerator pedal. A control device for an electric vehicle. In the control apparatus of the electric vehicle described in any one of Claim 1 to Claim 3,
The automatic transmission is a stepped transmission that automatically changes a plurality of shift stages having different gear ratios according to a vehicle state;
The torque change rate selection processing means sets the torque change rate for each shift stage when the driving scene is selected by selecting one shift stage among a plurality of shift stages, and the shift stage is on the deceleration side. as set to a large value, shift speed control device for an electric vehicle, characterized in that to set the smaller value is a constant velocity or acceleration side.