JP5699533B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle.

  In a parallel hybrid vehicle using an internal combustion engine (engine) and a motor generator (motor generator) as drive sources, the rotation speed control motor torque target value is the second clutch torque capacity basic target while executing the rotation speed control of the motor generator. When the value is smaller than the value, the rotational speed control second clutch torque capacity basic target value is corrected to a value larger than the second clutch torque capacity basic target value, thereby causing the deviation between the transmission torque and the actual value to approach zero. It is known ([0083] of Patent Document 1).

JP 2010-83417 A

  However, in a parallel hybrid vehicle that uses an engine and a motor generator as drive sources, when there is a power generation request to the motor generator while maintaining the idling speed, the torque of the motor generator is particularly high if the internal resistance of the battery is high. The battery voltage fluctuation increases with respect to the fluctuation, and as a result, the battery may become overvoltage.

  The problem to be solved by the present invention is to suppress overvoltage and protect the battery even when the internal resistance of the battery is high.

The present invention relates to a hybrid vehicle including an internal combustion engine and a motor generator as a drive source, a clutch between the motor generator and a drive wheel, and a battery that discharges and charges between the motor generator and at least an idle vehicle. If there is a drive request at the rotational speed, there is a power generation request to the motor generator, and the internal resistance of the battery is equal to or greater than a predetermined value, switch from the motor generator speed control to the internal combustion engine speed control, the speed control of the internal combustion engine, only when the internal combustion engine is reduced rotational speed exceeds the driving keeping range of the rotation speed, the rotation speed control about the deviation exceeds the driving keeping range electrostatic dynamic generator By executing the above, the above-mentioned problem is solved.

  According to the present invention, when the rotational speed control of the internal combustion engine is executed, the torque of the motor generator can be fed forward and the torque fluctuation of the motor generator is suppressed. As a result, even if the internal resistance of the battery is high, an overvoltage can be suppressed and the battery can be protected.

1 is a block diagram showing an overall configuration of a hybrid vehicle according to an embodiment of the present invention. It is a figure which shows the power train of the hybrid vehicle which concerns on other embodiment of this invention. It is a figure which shows the power train of the hybrid vehicle which concerns on further another embodiment of this invention. It is a control block diagram which shows the detail of the integrated control unit of FIG. It is a figure which shows an example of the target drive force map referred by the target drive torque calculating part of FIG. It is a figure showing an example of the driving mode map referred by the target driving mode calculating part of FIG. It is a figure explaining the subject of the overvoltage of the battery produced by the torque fluctuation of a motor generator. It is a flowchart which shows the control content of the integrated control unit of FIG. FIG. 9 is a determination block diagram showing engine speed control execution determination in step S5 of FIG. 8. It is a figure which shows the switching map of engine speed control of step S5 of FIG. It is a flowchart which shows the subroutine of step S5 of FIG. It is a time chart which shows the process result of FIG.8 S5. It is a flowchart which shows the subroutine of step S6 of FIG. It is a time chart of step S6 of FIG.

  A hybrid vehicle 1 according to an embodiment of the present invention is a parallel vehicle that uses a plurality of power sources such as an internal combustion engine and a motor generator for driving the vehicle, and the hybrid vehicle 1 of this example shown in FIG. (Hereinafter referred to as engine) 10, first clutch 15, motor generator (hereinafter referred to as motor generator) 20, second clutch 25, battery 30, inverter 35, automatic transmission 40, propeller shaft 51, differential gear unit 52, drive shaft 53 and left and right drive wheels 54.

  The engine 10 is one of driving sources that output driving energy by burning fuel such as gasoline, light oil, and the like. Based on a control signal from the engine control unit 70, the valve opening of the throttle valve and the fuel injection valve are controlled. Control the fuel injection amount.

  The first clutch 15 is interposed between the output shaft of the engine 10 and the rotation shaft of the motor generator 20, and connects and disconnects (ON / OFF) the power transmission between the engine 10 and the motor generator 20. Examples of the first clutch 15 include a wet multi-plate clutch that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid. In the first clutch 15, the hydraulic pressure of the hydraulic unit 16 is controlled based on a control signal from the integrated control unit 60, whereby the clutch plate of the first clutch 15 is engaged (including a slip state) or released. A dry clutch may be adopted as the first clutch 15.

  The motor generator 20 is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The motor generator 20 is provided with a rotation angle sensor 21 such as a resolver for detecting the rotor rotation angle. The motor generator 20 functions as an electric motor or a generator. When three-phase AC power is supplied from the inverter 35, the motor generator 20 is driven to rotate (powering).

  On the other hand, when the rotor is rotated by an external force, motor generator 20 generates AC power by generating electromotive force at both ends of the stator coil (regeneration). The AC power generated by the motor generator 20 is converted into DC power by the inverter 35 and then charged to the battery 30. In addition, since negative torque is generated in the motor generator 20 during regeneration, the driving wheel also has a braking function.

  The battery 30 may be an assembled battery in which a plurality of lithium ion secondary batteries, nickel hydride secondary batteries, and the like are connected in series or in parallel. A current / voltage sensor 31 and a temperature sensor 32 for estimating an internal resistance value are attached to the battery 30, and these detection results are output to the motor control unit 80.

  The second clutch 25 is interposed between the motor generator 20 and the left and right drive wheels 54 to connect and disconnect (ON / OFF) the power transmission between the motor generator 20 and the left and right drive wheels 54. The second clutch 25 can be exemplified by, for example, a wet multi-plate clutch, similar to the first clutch 15 described above. In the second clutch 25, the hydraulic pressure of the hydraulic unit 26 is controlled based on a control signal from the transmission control unit 90, whereby the clutch plate of the second clutch 25 is engaged (including a slip state) / released.

  The automatic transmission 40 is a stepped transmission that switches the gear ratio such as the seventh forward speed and the first reverse speed in stages, and automatically switches the gear ratio according to the vehicle speed, the accelerator opening, and the like. The gear ratio of the automatic transmission 40 is controlled based on a control signal from the transmission control unit 90.

  As shown in FIG. 1, the second clutch 25 may be one in which several frictional engagement elements are used among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission 40. Alternatively, the second clutch 25 may be a dedicated clutch different from the automatic transmission 40. For example, as shown in FIG. 2, the second clutch 25 may be a dedicated clutch interposed between the output shaft of the motor generator 20 and the input shaft of the automatic transmission 40. Alternatively, as shown in FIG. 3, the second clutch 25 may be a dedicated clutch interposed between the output shaft of the automatic transmission 40 and the propeller shaft 51. 2 and 3 are diagrams showing the configuration of a hybrid vehicle according to another embodiment. In FIGS. 2 and 3, the configuration other than the power train is the same as that in FIG. Indicates.

  The automatic transmission 40 according to the present embodiment can use a general stepped automatic transmission, and a detailed configuration thereof is omitted. However, a plurality of frictions that are engaged at each gear stage of the automatic transmission 40 are omitted. When the second clutch 25 is configured by diverting some of the frictional engagement elements among the engagement elements, the frictional engagement element to be engaged at the current shift stage among the frictional engagement elements in the automatic transmission 40 is the second clutch. 25.

  Further, the automatic transmission 40 is not particularly limited to the above-described stepped automatic transmission with 7 forward speeds and 1 reverse speed, and may be another stepped transmission with 5 forward speeds and 1 reverse speed, for example. Good. When the second clutch 25 is configured without using the frictional engagement element of the automatic transmission 40, a continuously variable automatic transmission can also be used.

  Returning to FIG. 1, the output shaft of the automatic transmission 40 is connected to the left and right drive wheels 54 via a propeller shaft 51, a differential gear unit 52, and left and right drive shafts 53. In FIG. 1, reference numeral 55 denotes left and right steering front wheels. 1 to 3 exemplify a rear-wheel drive hybrid vehicle, it may be a front-wheel drive hybrid vehicle or a four-wheel drive hybrid vehicle.

  The hybrid vehicle 1 according to the present embodiment sets the drive source to the engine 10 and / or the motor generator 20, in other words, according to the engaged / slip / release state of the first and second clutches 15 and 25. It is possible to switch to each travel mode described below.

  The motor generator use travel mode (hereinafter referred to as EV travel mode) is a mode in which the first clutch 15 is disengaged and the second clutch 25 is engaged to travel using only the power of the motor generator 20 as a drive source.

  The engine use travel mode (hereinafter referred to as HEV travel mode) is a mode in which both the first clutch 15 and the second clutch 25 are engaged and the vehicle travels while including at least the power of the engine 10 as a drive source.

  In addition to the EV traveling mode and the HEV traveling mode, the first clutch 15 is engaged and the second clutch 25 is in the slip state, and the engine uses slip traveling mode (hereinafter referred to as WSC) that travels while including the power of the engine 10 as a drive source. Travel mode, Wet Start Clutch) may be set. The WSC traveling mode is a mode in which creep traveling can be achieved particularly when the state of charge (SOC) of the battery 30 is lowered or when the temperature of the cooling water of the engine 10 is low.

  In addition to the EV travel mode and the HEV travel mode, the first clutch 15 is released while the engine 10 is operated, the second clutch 25 is set in a slip state, and only the power of the motor generator 20 is traveled. A motor use slip running mode (hereinafter referred to as MWSC running mode) may be set. In the above-described WSC travel mode, when the road surface slope is an uphill road or the like with a predetermined value or more, the driver adjusts the accelerator pedal and the state in which the vehicle is stopped or at the slow start state (so-called stall stop state) continues. The state in which the slip amount of the second clutch 25 is excessive continues, and therefore the second clutch 25 may be overheated. This is because engine stall occurs when the engine speed is made lower than the idle speed. Therefore, in this embodiment, in such a case, the MWSC travel mode is selected in order to prevent the second clutch 25 from being overheated.

  When shifting from the EV travel mode to the HEV travel mode, the engine can be started by engaging the released first clutch 15 and using the torque of the motor generator 20.

  Further, in the HEV travel mode, an engine travel mode, a motor assist travel mode, and a travel power generation mode are set. In the engine running mode, the drive wheel 54 is moved using only the engine 10 as a power source without driving the motor generator 20. In the motor assist travel mode, both the engine 10 and the motor generator 20 are driven, and the drive wheels 54 are moved using these two as power sources. In the traveling power generation mode, the drive wheel 54 is moved using the engine 10 as a power source, and at the same time, the motor generator 20 is caused to function as a generator to charge the battery 30.

  In addition to the modes described above, when the vehicle is stopped, the motor generator 20 is made to function as a generator by using the power of the engine 10 to charge the battery 30 or supply power to the electrical components. May be provided.

  The control system of the hybrid vehicle 1 in this embodiment includes an integrated control unit 60, an engine control unit 70, a motor control unit 80, and a transmission control unit 90, as shown in FIG. These control units 60, 70, 80, and 90 are connected to each other through, for example, CAN communication.

  The engine control unit 70 outputs a command for controlling the engine operating point (engine speed Ne, engine torque Te) to the throttle valve actuator of the engine 10 according to the target engine torque command from the integrated control unit 60 and the like. Information on the engine speed Ne and the engine torque Te is output to the integrated controller 60 via the CAN communication line.

  The motor control unit 80 inputs information from the rotation angle sensor 21 provided in the motor generator 20, and according to the target motor generator torque command value from the integrated control unit 60, the operating point of the motor generator 20 (motor rotation). A command for controlling the number Nm and the motor torque Tm) is output to the inverter 35. The motor control unit 80 calculates and manages the SOC of the battery 30 based on the current value and the voltage value detected by the current / voltage sensor 31. The battery SOC information is used as control information for the motor generator 20 and is sent to the integrated control unit 60 via CAN communication. Further, the motor control unit 80 estimates the motor generator torque Tm based on the value of the current flowing through the motor generator 20 (the power running control torque and the regenerative control torque are distinguished based on whether the current value is positive or negative). Information on the motor generator torque Tm is sent to the integrated control unit 60 via CAN communication. Further, the motor control unit 80 sends the battery temperature detected by the temperature sensor 32 to the integrated control unit 60 in order to estimate the internal resistance value of the battery 30.

  The transmission control unit 90 inputs sensor information from an accelerator opening sensor 91, a vehicle speed sensor 92, a second clutch hydraulic pressure sensor 93, and an inhibitor switch 94 that outputs a signal corresponding to the position of the shift lever operated by the driver. In response to the second clutch control command from the integrated control unit 60, a command for controlling the engagement / release of the second clutch 25 is output to the hydraulic unit 26. Information on the accelerator opening APO, the vehicle speed VSP, and the inhibitor switch is sent to the integrated control unit 60 via CAN communication.

The integrated control unit 60 manages the energy consumption of the entire hybrid vehicle 1 and controls the function of causing the hybrid vehicle 1 to travel efficiently. The integrated control unit 60 includes a second clutch output rotational speed sensor 61 that detects an output rotational speed N2 _out of the second clutch 25, a second clutch torque sensor 62 that detects a transmission torque capacity _TCL2 of the second clutch 25, and a brake hydraulic pressure. Sensor information is acquired from the sensor 63, the temperature sensor 64 that detects the temperature of the second clutch 25, and the G sensor 65 that detects the longitudinal acceleration and lateral acceleration of the vehicle. The integrated control unit 60 also acquires sensor information obtained through CAN communication in addition to these pieces of information.

  Based on these pieces of information, the integrated control unit 60 controls the operation of the engine 10 according to the control command to the engine control unit 70, the operation control of the motor generator 20 based on the control command to the motor control unit 80, and the transmission control unit 90. Control of the automatic transmission 40 according to the control command for the first clutch 15, engagement / release control of the first clutch 15 according to the control command for the hydraulic unit 16 of the first clutch 15, and control command for the hydraulic unit 26 of the second clutch 25 Engagement / release control of the second clutch 25 is executed.

  Next, the control executed by the integrated control unit 60 will be described. FIG. 4 is a control block diagram showing details of the integrated control unit 60. The control described below is repeatedly executed, for example, every 10 msec. As shown in FIG. 4, the integrated control unit 60 includes a target drive torque calculator 601, a target travel mode calculator 602, a target input torque calculator 603, a target input speed calculator 604, and a target clutch torque calculator 605. .

  The target driving torque calculation unit 601 uses the predetermined target driving force map to perform target driving based on the accelerator opening APO detected by the accelerator opening sensor 91 and the vehicle speed VSP detected by the vehicle speed sensor 92. Torque tFo0 is calculated. FIG. 5 shows an example of the target driving force map.

  The target travel mode calculation unit 602 calculates and selects a target travel mode with reference to the travel mode map shown in FIG. In the travel mode map of FIG. 6, EV travel mode, WSC travel mode, and HEV travel mode regions are set in accordance with the vehicle speed VSP and the accelerator opening APO. In this travel mode map, the switching line from the EV travel mode or the HEV travel mode to the WSC mode indicates that the engine 10 idles when the automatic transmission 40 is at the first speed in the region below the predetermined accelerator opening APO1. It is set in a region lower than the lower limit vehicle speed VSP1 at which the rotational speed is smaller than the rotational speed. Further, since a large driving force is required in a region where the accelerator opening APO1 is equal to or larger than the predetermined accelerator opening APO1, the WSC travel mode is set up to a vehicle speed VSP1 'region that is higher than the lower limit vehicle speed VSP1. The target travel mode is calculated in consideration of the SOC (or target charge / discharge power tP) of the battery 30 detected by the system state detection unit 606 and the gradient of the vehicle.

  The target input torque calculation unit 603, the target input rotation number calculation unit 604, and the target clutch torque calculation unit 605 include an accelerator pedal opening APO, a target drive torque tFoO, a target travel mode, a vehicle speed VSP, and a clutch slip rotation number detection unit 607. Based on the slip rotation speed, the output shaft rotation speed by the output shaft rotation speed detection unit 608, and the target charge / discharge power tP, the target engine torque, the target motor generator torque, and the target clutch torque capacity are respectively calculated as these operating point arrival targets. To do.

  Then, the target engine torque / target motor torque calculation unit 609 performs engine torque based on the target input torque calculated by the target input torque calculation unit 603 and the target travel mode calculated by the target travel mode calculation unit 602. The target engine torque is output to the control unit 610 and the target motor torque is output to the motor torque / rotation speed control unit 611.

  Further, the target input rotation speed calculated by the target input rotation speed calculation unit 604 is output to the motor torque / rotation speed control unit 611, and the motor torque / rotation speed control unit 611 is output to the transient running mode calculation unit 614. Depending on whether the control mode of the motor generator 20 calculated in this way is torque control or rotational speed control (speed control), either the target input rotational speed or the target motor torque is output to the motor generator 20.

  The target clutch torque calculated by the target clutch torque calculation unit 605 is output to the target clutch torque capacity control unit 612, and the transmission torque of the first and second clutches is controlled.

  The motor limit torque calculation unit 615 is based on the target motor input rotation number calculated by the target input rotation number calculation unit 604 and the target clutch torque capacity calculated by the target clutch torque calculation unit 605. The target motor torque calculated by the target engine torque / target motor torque calculation unit 609 is limited based on the result.

  In the hybrid vehicle described above, as shown in FIG. 7, when the motor generator 20 is controlled at the rotational speed in order to maintain the idle rotational speed of the engine 10, there is a power generation request to the motor generator 20. The voltage fluctuation of the battery 30 increases due to the torque fluctuation of the motor generator 20. For this reason, especially when the internal resistance of the battery 30 is high, the voltage of the battery 30 may exceed the allowable upper limit value and become an overvoltage.

  Therefore, the control device of this example includes an engine speed control execution determination unit 613 and a transient travel mode calculation unit 614 as shown in FIG. When engine speed control execution determination unit 613 detects a request to drive engine 10 at at least an idle speed, a request to regenerate motor generator 20, and an internal resistance value of battery 30 being equal to or greater than a predetermined value. Next, the rotational speed control of the engine 10 is executed. In this example, the torque control of the engine 10 is switched to the rotational speed control, and the rotational speed control of the motor generator 20 is switched to the torque control.

  In order to protect the battery 30 and the motor generator 20 at a low temperature or a high temperature, the input / output power to the battery 30 or the motor generator 20 is limited, or the battery 30 is protected at a high SOC or a low SOC. However, in such a situation, it is difficult to drive the motor generator 30 and maintain the idling speed. The engine speed control execution determination unit 613 may execute the engine speed control under such conditions.

  The detection of the request for driving the engine 10 at at least the idling speed is determined based on the calculation result from the target travel mode calculation unit 602. The detection of the request for regenerative driving of the motor generator 20 is also determined based on the calculation result from the target travel mode calculation unit 602. The detection of the internal resistance value of the battery 30 is estimated by calculation from the use history, charge / discharge characteristics, etc. of the battery 30 output from the motor control unit 80, and the internal resistance value is correlated with the environmental temperature of the battery 30. This is done by estimating the internal resistance value from the ambient temperature. The internal resistance value in this example is detected by the temperature sensor 32. Details of the control contents will be described later.

  Next, the contents of control will be described. FIG. 8 is a flowchart showing the control contents of the integrated control unit 60. The integrated control unit 60 receives data from the control units of the engine control unit 70, the motor control unit 80, and the transmission control unit 90 in step S1. In addition, in step S2, the second clutch output rotational speed sensor 61, the second clutch torque sensor 62, the brake hydraulic pressure sensor 63, the temperature sensor 64, the G sensor 65, the temperature sensor 32, and other sensors sent via CAN communication. Read the sensor value from.

  The target drive torque calculation unit 601 of the integrated control unit 60 refers to the driving force map of FIG. 5 from the accelerator opening APO from the accelerator opening sensor 91 and the vehicle speed VSP from the vehicle speed sensor 92 in step S3, and hybrid vehicle The target drive torque required for is calculated. The target drive torque is distributed to the target engine torque and the target motor torque in step S9 according to the travel mode obtained in the next step S4.

  In step S4, the target travel mode calculation unit 602 of the integrated control unit 60 refers to the travel mode map of FIG. 6 based on the target drive torque, the SOC of the battery 30, the accelerator opening APO, the vehicle speed VSP, the vehicle gradient, and the like. The travel mode, HEV travel mode, or WSC travel mode is selected.

  The engine speed control execution determination unit 613 of the integrated control unit 60 uses the motor generator 20 and the battery 30 for the power generation torque of the motor generator 20 calculated in step S3 from the SOC and vehicle state of the battery 30 in step S5. The target power generation torque is calculated in consideration of restrictions for protecting the power. In this case, it is determined whether it is appropriate to execute the input rotation speed control of the engine 10 or whether it is appropriate to execute the input rotation speed control of the motor generator 20.

  FIG. 9 is an example of a determination block diagram of the engine speed control execution determination unit 613. A request based on the motor torque of the motor generator 20, such as an output limit of the inverter 35 and a motor limit torque, a request based on the SOC of the battery 30, or the battery 30 When the vehicle travel state such as the target travel mode, the requested driving force, the vehicle speed, and the gear position is satisfied, the torque control of the engine 10 is changed to the engine speed control. Set the engine speed control execution flag to be switched ON.

  FIG. 10 is a switching map of the engine speed control execution flag in response to a request based on the temperature of the battery 30. When the internal resistance value of the battery 30 exceeds a predetermined threshold, the engine speed control execution flag is set to ON and the engine 10 is turned on. The rotation speed control is executed. On the other hand, when the internal resistance value of the battery 30 becomes smaller than a predetermined threshold value during the engine speed control, the engine speed control execution flag is set to OFF and the torque control of the engine 10 is performed. Execute. By providing a predetermined hysteresis for the switching threshold value between the torque control and the rotational speed control of the engine 10, the hunting phenomenon accompanying the switching is prevented.

  FIG. 11 is a flowchart showing the determination procedure of the engine speed control execution determination unit 613. The internal resistance value of the battery 30 correlates with the battery temperature (the internal resistance value increases as the battery temperature decreases). This is an example in which the battery temperature is set as the switching threshold. First, when the battery temperature detected by the temperature sensor 32 in step S501 is equal to or lower than a preset threshold temperature, the process proceeds to step S502, and the engine speed control execution flag is set to ON.

  On the other hand, when the battery temperature is higher than the threshold temperature in step S501, the process proceeds to step S503, and it is determined whether or not the temperature is equal to or higher than a temperature obtained by adding a predetermined hysteresis value to the threshold temperature. When the battery temperature is equal to or higher than the temperature obtained by adding a predetermined hysteresis value to the threshold temperature, it is determined that the internal resistance value is low, the process proceeds to step S504, and the engine speed control execution flag is set to OFF. If the battery temperature is lower than the threshold temperature plus a predetermined hysteresis value in step S503, the value of the engine speed control execution flag (ON or OFF) currently set to prevent hunting is maintained. To do.

  When the engine speed control execution flag is set to ON in step S5 of FIG. 8, a command for executing the engine speed control is output to the engine control unit 70 in step S12 described later, and the motor torque is supplied to the motor control unit 80. A command to execute control is output. Thereby, as shown in FIG. 12, while the idling engine speed is maintained by the engine speed control of the engine 10, the motor generator 20 is torque-controlled by feedforward in response to the power generation request, so that the actual motor torque fluctuations are reduced. As a result, the fluctuation of the electric power charged in the battery 30 is reduced. Therefore. Especially when the internal resistance value of the battery 30 is high, the battery voltage can be prevented from becoming an overvoltage.

  In step S6 of FIG. 8, the target input torque calculation unit 603, the target input rotation speed calculation unit 604, and the target clutch torque calculation unit 605 of the integrated control unit 60 are changed so as to be in the travel mode selected in step S4. The target engine torque, target motor generator torque, and target clutch torque capacity are respectively calculated and output to the engine control unit 70, the motor control unit 80, and the transmission control unit 90, respectively.

  In this example, the engine 10 is switched from torque control to rotational speed control in step S5, and when the motor generator 20 is switched from rotational speed control to torque control, the transient running mode is implemented until the torque of the engine 10 is stabilized. . A request for maintaining the idle speed of the engine 10, a power generation request to the motor generator 20, and a switching procedure to engine speed control executed when the internal resistance value of the battery 30 is higher than a predetermined threshold are shown in FIG. It is shown in a flowchart and FIG. 14 shows a time chart.

  First, in step S601 of FIG. 13, it is confirmed that the engine speed control execution flag is ON. If it is OFF, the process proceeds to step S607, where the transient control mode z is set to 0 (normal mode), and the engine 10 is torque controlled. The motor generator 20 is set to control the rotational speed. On the other hand, if the engine speed control execution flag is ON in step S601, the process proceeds to step S602, where it is determined whether the transient control mode z is 0. If z = 0, the process proceeds to step S608. The transient control mode z is set to 1 (engine torque stabilization waiting mode). Then, the engine 10 is switched to the rotational speed control, and the motor generator 20 continues the rotational speed control. In the normal mode with z = 1 and the engine torque stabilization waiting mode with z = 1, the upper limit torque and the lower limit torque of the motor generator 20 maintain the initial set values.

  After returning to step S601 after step S608 set to z = 1, the process proceeds to step S605 via steps S602 and S603, and the stability of the engine torque is determined. The determination of the engine torque may be determined that the engine torque is stable when the fluctuation range by the torque sensor is within a predetermined value, or a time until the torque is stabilized after the characteristics of the engine 10 are verified in advance. Therefore, it may be determined that the engine torque is stable. Until the engine torque is stabilized in step S605, the process proceeds to step S608 and the transient control mode z is maintained at 1. However, when the engine torque is stabilized, the process proceeds to step S609 and the transient control mode z is set to 2 (motor control transition preparation mode). Set to. Then, although the rotational speed control of the engine 10 and the rotational speed control of the motor generator 20 are maintained, the upper limit torque and the lower limit torque of the motor generator 20 are limited as shown in FIG. 14 when the motor generator 20 executes the torque control. Asymptotic to each value.

  After returning to step S601 after step S609 set to z = 2, the process proceeds to step S606 via step S602, step S603, and step S604, and whether or not the transition of the upper limit torque and the lower limit torque of the motor generator 20 is completed. Judging. This determination can be made based on the elapsed time. If the transition of the limit torque has not been completed, the transient control mode z = 2 is maintained through step S609. However, when the transition is completed, the process proceeds to step S610, where the transient control mode z is set to 3 (engine speed control mode). Set. Then, the motor generator 20 is switched to torque control while maintaining the rotational speed control of the engine 10.

  When the engine 10 is to be switched from normal torque control to rotational speed control, it is necessary to switch the ignition timing and the like, and the engine torque decreases transiently, particularly when the power generation torque is applied to the motor generator 20. There is a risk that engine speed will decrease and engine stall or vibration will occur. However, in this example, by setting such a transient control mode, it is possible to suppress the occurrence of engine stall and vibration accompanying fluctuations in engine torque, and it is possible to sufficiently respond to power generation requirements.

  Although the transient control mode z = 3 corresponds to the engine speed control mode of the present example, a guaranteed range (also referred to as a drive maintainable range) in which the engine 10 can maintain the speed control by the speed control of the engine 10 in terms of performance. ), The rotational speed control of the motor generator 20 is executed only for the deviation exceeding the drive sustainable range. In other words, the idling engine speed of the engine 10 is guaranteed by the engine speed control within the range where the engine 10 can be maintained, but if the engine 10 exceeds the engine sustainable range, the engine speed decreases and the engine stalls, etc. It is for producing. By not performing the rotational speed control of the motor generator 20 within the drive sustainable range of the engine 10, it is possible to maintain a state where the rotational speed is not continuously stalled while securing a required power generation amount.

  In order to execute the rotational speed control of the motor generator 20 only for the deviation exceeding the drive sustainable range of the engine 10, for example, the power generation torque is set by feedforward with respect to the target output torque of the motor generator 20, and the engine Only when the rotational speed has decreased beyond the 10 drive sustainable range, the motor torque corresponding to the deviation of the rotational speed from the target value is added.

  Returning to FIG. 8, the target input rotational speed calculation unit 604 of the integrated control unit 60 calculates the target motor input rotational speed based on the output shaft rotational speed of the motor generator 20 by the output shaft rotational speed detection unit 608 in step S7. And output to the motor torque / rotation speed controller 611.

  The target input torque calculator 603 of the integrated control unit 60 calculates the target input torque in consideration of the target drive torque calculated by the target drive torque calculator 601 in step S8 and the protection of various devices constituting the motor generator 20. To do. In step S9, the target engine torque / motor torque calculation unit 609 of the integrated control unit 60 determines whether the engine 10 and the motor generator are based on the target input torque calculated in step S8, the power generation request from the motor control unit 80, or the like. The target value of torque to be distributed to 20 is calculated.

  In step S10 of FIG. 8, the clutch torque capacities of the first clutch CL1 and the second clutch 25 are calculated and output to the hydraulic units 16 and 26 in step S12. In step S11, a limit value is calculated in consideration of the torque margin for the rotational speed variation and the disturbance correction for the target motor torque in the WSC travel mode.

  As described above, according to the hybrid vehicle control device of this example, the request for driving the engine 10 at least at the idle rotation speed, the request for regenerative driving of the motor generator 20, and the internal resistance value of the battery 30 are equal to or greater than a predetermined value. When this is detected, the rotational speed control of the engine 10 is executed. As shown in FIG. 12, the idle rotational speed is maintained by the rotational speed control of the engine 10, while the motor generator 20 responds to the power generation request. Is controlled by feedforward, so that the actual motor torque fluctuation is reduced, and accordingly, the fluctuation of the electric power charged in the battery 30 is also reduced. Therefore. Especially when the internal resistance value of the battery 30 is high, the battery voltage can be prevented from becoming an overvoltage.

  When switching to the rotational speed control of the engine 10, the transient control mode indicated by z = 0 → 1 → 2 → 3 in FIG. 14 is set to suppress the occurrence of engine stall or vibration due to engine torque fluctuation. Therefore, it is possible to respond sufficiently to power generation requirements.

  Further, when the engine 10 exceeds the guaranteed range (also referred to as the drive sustainable range) in which the engine 10 can maintain the rotational speed control by the rotational speed control of the engine 10, only the deviation exceeding the drive maintainable range is motored. Since the rotational speed control of the generator 20 is executed, the rotational speed control is continuously performed while ensuring the required power generation amount by not executing the rotational speed control of the motor generator 20 within the drive sustainable range of the engine 10. It can be kept in a state that does not.

  The engine 10 corresponds to the internal combustion engine according to the present invention, the motor generator 20 corresponds to the motor generator according to the present invention, the second clutch 25 corresponds to the clutch according to the present invention, and the target travel mode calculation is performed. The unit 602 corresponds to the internal combustion engine drive request detection means and the regenerative drive request detection means according to the present invention, the temperature sensor 32 corresponds to the internal resistance detection means according to the present invention, and the engine speed control execution determination unit 613 This corresponds to the control means according to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle 10 ... Engine 15 ... 1st clutch 20 ... Motor generator 25 ... 2nd clutch 30 ... Battery 35 ... Inverter 40 ... Automatic transmission 60 ... Integrated control unit 70 ... Engine control unit 80 ... Motor control unit 90 ... Transmission control unit

Claims (2)

An internal combustion engine, a motor generator, a drive wheel connected directly or indirectly to the output shaft of the internal combustion engine and the output shaft of the motor generator, and a drive between the motor generator and the drive wheel A control device that outputs a control signal to a hybrid vehicle including a clutch that connects and disconnects a force, and a battery that supplies power to the motor generator and charges power from the motor generator,
An internal combustion engine drive request detection means for detecting a request to drive the internal combustion engine at at least an idle speed;
Regenerative drive request detection means for detecting a request to regenerate the motor generator;
Internal resistance detection means for detecting the internal resistance value of the battery;
The rotation of the motor generator is detected when it is detected that the request to drive the internal combustion engine at at least the idle speed, the request to regenerate the motor generator, and the internal resistance value of the battery is equal to or greater than a predetermined value. Control means for switching from number control to rotation speed control of the internal combustion engine,
The control means, the rotational speed control of the internal combustion engine, the internal combustion engine only when the rotational speed exceeds the driving keeping range of the rotation speed is lowered, with the deviation exceeds the drivable maintain range control apparatus for a hybrid vehicle that performs the rotation speed control of the previous SL motor generator. In the hybrid vehicle control device according to claim 1,
Further comprising stability detection means for detecting the stability of the output torque of the internal combustion engine,
When the control means switches from the rotational speed control of the motor generator to the rotational speed control of the internal combustion engine, the control means controls the rotational speed of the motor generator and the internal combustion engine until the output torque of the internal combustion engine becomes stable. A control apparatus for a hybrid vehicle that executes rotation speed control in parallel and switches the motor generator to torque control after the output torque of the internal combustion engine is stabilized.

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