JP6032113B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle including a plurality of drive sources.

  Japanese Unexamined Patent Application Publication No. 2010-111193 (Patent Document 1) discloses that in a vehicle including a motor and an engine as a drive source, when the temperature of an inverter that drives the motor is high, the motor torque is limited and the motor torque is limited. It is disclosed that a vehicle stop state is maintained by compensating for a shortage of force by increasing engine torque.

JP 2010-111193 A JP 2007-185069 A

  However, in the vehicle disclosed in Patent Document 1, when the inverter temperature is high, the engine is used more excessively than when the inverter temperature is not high. As a result, the user may feel uncomfortable or the durability of the engine may be reduced.

The present invention has been made in order to solve the above-described problems, and its object is to provide a vehicle including a first drive source and a second drive source, even when the output of the first drive source is being limited . The second drive source is prevented from being excessively used.

  A vehicle according to the present invention includes a drive device including a first drive source and a second drive source, and configured to be able to transmit power of at least one of the first drive source and the second drive source to drive wheels, and a drive device. And a control device configured to be controllable. When performing the predetermined vehicle behavior control, if the limiting control for limiting the output of the first drive source to less than a predetermined value is being performed, the control device guarantees the output of the driving device more than before the limiting control is performed. Relaxation control that relaxes the range is executed, and when the guaranteed range after relaxation cannot be satisfied by the output of the first drive source, the shortage is compensated by the output of the second drive source.

  Preferably, the second drive source includes an internal combustion engine. The control device executes the relaxation control when the limit control is being executed and when the internal combustion engine is started.

Preferably, the first drive source is a rotating electric machine. In vehicle behavior control, when starting an internal combustion engine while the vehicle is running, the output of the drive device is set within a guaranteed range by generating a force from the rotating electrical machine to cancel the reaction force generated by starting the internal combustion engine. Reaction force control.
Relaxation control is control that expands the range of the guaranteed range by reaction force control.

  Preferably, the vehicle behavior control is a reverse prevention control for setting a reverse prevention driving force for preventing the vehicle from retreating to a lower limit value or more. The relaxation control is control for lowering the lower limit value by the reverse prevention control.

  Preferably, the vehicle behavior control is a braking control for setting the braking force acting on the driving wheel by the rotational resistance of the driving device to a lower limit value or more. The relaxation control is control for lowering the lower limit value by the braking control.

  Preferably, the second drive source includes an internal combustion engine. When executing the relaxation control, the control device makes the relaxation amount of the guaranteed range at the start of the internal combustion engine larger than the relaxation amount of the guaranteed range when the internal combustion engine is not started.

According to the present invention, in a vehicle including a first drive source and a second drive source, it is possible to suppress excessive use of the second drive source even when the output of the first drive source is being limited. .

1 is an overall block diagram of a vehicle. It is a figure which shows the alignment chart of a power split device. It is a flowchart (the 1) which shows the processing content of ECU. FIG. 5 is a diagram (No. 1) illustrating a map used for setting a lowering prevention driving force lower limit value; It is a flowchart (the 2) which shows the processing content of ECU. It is a flowchart (the 3) which shows the processing content of ECU. FIG. 8 is a diagram (No. 2) illustrating a map used for setting a lower limit drive force lower limit value; It is a flowchart (the 4) which shows the processing content of ECU. It is a figure which shows the map used for the setting of an engine brake force lower limit. It is a flowchart (the 5) which shows the processing content of ECU. It is a figure which shows the map used for the setting of the allowable driving force range at the time of engine starting.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
[Embodiment 1]
FIG. 1 is an overall block diagram of a vehicle 1 according to the present embodiment. The vehicle 1 includes an engine 100, a first motor generator (hereinafter referred to as “first MG”) 200, a power split mechanism 300, a second motor generator (hereinafter referred to as “second MG”) 400, and a propeller shaft (output shaft). 560, driving wheel 82, PCU (Power Control Unit) 600, battery 700, SMR (System Main Relay) 710, and ECU (Electronic Control Unit) 1000.

  The engine 100 is an internal combustion engine that outputs power by burning fuel. The power of engine 100 is input to power split device 300.

  Power split device 300 splits the power input from engine 100 into power to output shaft 560 and power to first MG 200.

  Power split device 300 rotates sun gear (S) 310, ring gear (R) 320, pinion gear (P) 340 meshed with sun gear (S) 310 and ring gear (R) 320, and pinion gear (P) 340. It is a planetary gear mechanism having a carrier (C) 330 that is held to revolve freely.

  Carrier (C) 330 is connected to the crankshaft of engine 100. Sun gear (S) 310 is coupled to the rotor of first MG 200. Ring gear (R) 320 is connected to output shaft 560.

  The first MG 200 and the second MG 400 are AC rotating electrical machines, and function as both an electric motor (motor) and a generator (generator). The rotor of second MG 400 is connected to output shaft 560.

  Output shaft 560 is rotated by at least one of the power of second MG 400 and the power of engine 100 transmitted through power split mechanism 300. The rotational force of the output shaft 560 is transmitted to the left and right drive wheels 82 via the speed reducer 81. Thereby, the vehicle 1 travels. That is, vehicle 1 is a hybrid vehicle that can travel with the power of at least one of second MG 400 and engine 100.

  FIG. 2 shows an alignment chart of the power split mechanism 300. When power split mechanism 300 is configured as described above, the rotational speed of sun gear (S) 310 (= the rotational speed Nm1 of first MG 200), the rotational speed of carrier (C) 330 (= the rotational speed Ne of engine 100). The rotational speed of the ring gear (R) 320 (= the rotational speed Nm2 of the second MG 400, that is, the vehicle speed V) is a relationship that is connected by a straight line on the alignment chart of the power split mechanism 300 (if any two rotational speeds are determined) The rotation speed is also determined).

  Engine 100 is coupled to output shaft 560 via power split mechanism 300. Therefore, in order to transmit the output torque of engine 100 (hereinafter referred to as “engine torque Te”) to output shaft 560, the output torque of first MG 200 (hereinafter referred to as “first MG torque Tm1”) is the reaction force of engine torque Te. It is necessary to act in the direction (negative direction) that it takes charge of. Torque transmitted from engine 100 to output shaft 560 via power split mechanism 300 (hereinafter referred to as “engine direct torque Tep”) is expressed by the following equation (1) using first MG torque Tm1.

Tep = −Tm1 × (1 / ρ) (1)
As can be seen from the above equation (1), the engine direct torque Tep can be adjusted by controlling the first MG torque Tm1 responsible for the reaction force. “Ρ” is a gear ratio in the power split mechanism 300.

  On the other hand, second MG 400 is directly connected to output shaft 560. Therefore, the output torque of second MG 400 (hereinafter referred to as “second MG torque Tm2”) is directly transmitted to output shaft 560.

  Therefore, the torque (hereinafter also referred to as “vehicle drive torque Tp”) transmitted from drive device (engine 100, first MG 200 and second MG 400) to output shaft 560 is the sum of second MG torque Tm2 and engine direct torque Tep. Become.

  Returning to FIG. 1, PCU 600 includes a boost converter and an inverter. Boost converter is arranged between battery 700 and the inverter, and performs voltage conversion between them. The inverter is arranged between first MG 200 and second MG 400 (hereinafter also simply referred to as “MG” without distinguishing both) and the converter, and performs power conversion between the two. PCU 600 converts the DC power supplied from battery 700 into AC power having a voltage capable of driving MG. Thereby, MG is driven. The PCU 600 converts AC power generated by the MG into DC power having a voltage that can charge the battery 700. Thereby, the battery 700 is charged.

  Battery 700 is a secondary battery that stores DC power for driving MG. The battery 700 typically includes nickel metal hydride and lithium ions. Note that a large-capacity capacitor may be used instead of the battery 700.

  The SMR 710 is a relay for switching the connection state between the battery 700 and the electric system including the PCU 600.

  The vehicle 1 includes an engine rotation speed sensor 10, an output shaft rotation speed sensor 15, resolvers 21 and 22, and an accelerator position sensor 31. The engine rotation speed sensor 10 detects the rotation speed Ne of the engine 100. The output shaft rotation speed sensor 15 detects the rotation speed Np of the output shaft 560 as the vehicle speed V. Resolvers 21 and 22 detect rotation speed Nm1 of first MG 200 and rotation speed Nm2 of second MG 400, respectively. The accelerator position sensor 31 detects the operation amount A of the accelerator pedal by the user. Each of these sensors outputs a detection result to ECU 1000.

  Further, the vehicle 1 is provided with a start switch 35. The start switch 35 is a device for a user to input a system start request and a system stop request. The system activation request is a request for causing the control system of the vehicle 1 (hereinafter simply referred to as “vehicle system”) to be in an activated state (hereinafter referred to as “Ready-ON state”). The system stop request is a request for causing the vehicle system to stop (hereinafter referred to as “Ready-OFF state”). The start switch 35 outputs a system start request signal Ron to the ECU 1000 when a system start request is input, and outputs a system stop request signal Roff to the ECU 1000 when a system stop request is input.

  Further, the vehicle 1 is provided with a gradient sensor 36. The gradient sensor 36 detects the road surface gradient and outputs the detection result to the ECU 1000.

  Furthermore, the vehicle 1 is provided with a monitoring unit 37. The monitoring unit 37 monitors the voltage, current, temperature, etc. of the battery 700 and outputs the monitoring result to the ECU 1000.

  Further, the vehicle 1 is provided with a caution lamp (warning lamp) 38. The caution lamp 38 is turned on by the ECU 1000 during execution of “motor output restriction” described later. By turning on the caution lamp 38 (hereinafter, simply referred to as “caution lighting”), the user can recognize that the motor output restriction is being executed. Note that the user may be warned that the motor output restriction is being executed by another method (for example, voice or video).

  Further, the vehicle 1 is provided with temperature sensors 41 to 44. Temperature sensor 41 detects temperature THm1 of first MG 200. Temperature sensor 42 detects temperature THm2 of second MG 400. Temperature sensor 43 detects inverter temperature THi in PCU 600. Temperature sensor 44 detects boost converter temperature THc in PCU 600. Each of these temperature sensors 41-44 outputs a detection result to ECU1000.

  ECU 1000 incorporates a CPU (Central Processing Unit) and a memory (not shown), and executes predetermined arithmetic processing based on information stored in the memory and information from each sensor. ECU 1000 controls each device mounted on vehicle 1 based on the result of the arithmetic processing.

  ECU 1000 lowers the output upper limit value of second MG 400 when the condition for limiting the output of second MG 400 (hereinafter referred to as “motor output limiting condition”) is satisfied, compared to when the motor output limiting condition is not satisfied. Execute. Note that the motor output restriction condition includes, for example, a condition that the temperature THm2 of the second MG 400 exceeds the threshold temperature. The motor output restriction condition will be described in detail in the second embodiment described later.

  Further, the ECU 1000 performs “reverse prevention control”, “engine brake control”, and “reaction force control when starting the engine while traveling” as processing for controlling the behavior of the vehicle 1 (hereinafter also referred to as “vehicle behavior control”). Control such as.

  “Reverse prevention control” is to prevent the vehicle from moving against an intention of the user on an uphill road or the like (this phenomenon is also referred to as “slip down”, but is simply referred to as “reverse” hereinafter). Control. For example, when the vehicle 1 travels on an uphill road where the gradient exceeds a predetermined value, ECU 1000 calculates a lower limit value of driving force for preventing reverse movement (hereinafter referred to as “reverse prevention driving force lower limit value”) according to vehicle speed V. Then, the drive devices (engine 100, first MG 200, and second MG 400) are controlled so as to ensure that the actual vehicle driving force is in a range that is equal to or greater than the lower limit driving force lower limit value.

  “Engine brake control” is control for generating engine braking force. In the present embodiment, the “engine braking force” refers to a braking force that acts on the drive wheel 82 by the rotational resistance of the drive device (engine 100, first MG 200, and second MG 400). Therefore, “engine braking force” in the present embodiment is the sum of normal engine braking force due to friction of engine 100 and regenerative braking force due to second MG 400. That is, the regenerative braking by the second MG 400 is not performed by the engine 100, but is an object of “engine brake control” in the present embodiment. When the user requests engine braking (for example, when the user stops stepping on the accelerator pedal while traveling), ECU 1000 determines the lower limit of engine braking force (hereinafter referred to as “engine braking force lower limit”) as vehicle speed V. And the driving device is controlled so as to ensure that the actual engine braking force by the driving device is equal to or greater than the lower limit value of the engine braking force.

  “Reaction force control when starting the engine while traveling” is a force for canceling the force acting on the output shaft 560 by starting the engine (such as cranking or starting ignition of fuel) when the engine 100 is started while the vehicle is traveling. Is generated from the second MG 400 to suppress fluctuations in the driving force when the engine is started.

  For example, when there is a system activation request (Ready-ON request) while the vehicle is traveling in the Ready-OFF state, ECU 1000 first generates cranking force in the positive direction from first MG 200 to crank engine 100. . Due to this cranking, a negative reaction force acts on the output shaft 560, and thus the ECU 1000 generates a force for canceling the reaction force from the second MG 400. In addition, ECU 1000 starts fuel supply and ignition to engine 100 when the rotational speed Ne of engine 100 reaches a predetermined target rotational speed by cranking. The second MG 400 generates a force for suppressing the driving force fluctuation caused by the ignition start.

  ECU 1000 calculates a range of vehicle driving force that can be allowed when the running engine is started (hereinafter referred to as “allowable driving force range when starting the running engine”) according to vehicle speed V, and the actual vehicle driving force is calculated. The driving devices (engine 100, first MG 200, and second MG 400) are controlled so as to ensure that they are within the allowable driving force range.

  In the vehicle 1 having the above-described configuration, when the motor output after the limitation (output of the second MG 400) cannot satisfy the required driving force during the above-described motor output limitation, the ECU 1000 uses the output of the engine 100. Make up for the shortfall. Therefore, even when the motor output is being limited, the necessary driving force can be realized.

  On the other hand, when the motor output is restricted, the engine 100 operates differently than when the motor output is not restricted (normal time). Therefore, there is a concern that the user may feel uncomfortable due to a change in the rotational speed Ne of the engine 100, or that the engine 100 may be overheated or deteriorated due to excessive operation.

Therefore, when performing the above-described vehicle behavior control, the ECU 1000 according to the present embodiment guarantees the output of the drive device (vehicle driving force or vehicle braking force) more than before the motor output limitation when the motor output is being limited. Execute “guarantee relaxation control” to relax the scope. Then, when the guaranteed range after relaxation cannot be satisfied by the motor output, the shortage is compensated by the output of engine 100. In this specification, “guaranteed range” means a control range of the output of the driving device, and “relaxing the guaranteed range” means to widen the control range of the output of the driving device, or It means that the output limit of the driving device is relaxed by lowering the output control lower limit value.

  In the present embodiment, a case where the relaxation target by the guaranteed relaxation control is set to the “reverse prevention driving force lower limit value” will be described as an example.

FIG. 3 is a flowchart showing the contents of the guarantee relaxation control performed by ECU 1000.
In step (hereinafter, step is abbreviated as “S”) 10, ECU 1000 determines whether or not the motor output is being limited.

  If the motor output is being restricted (YES in S10), ECU 1000 determines whether or not the caution is being lit (that is, whether or not the user has been warned that the motor output is being restricted) (S11). .

  If the motor output is not being restricted (NO in S10) or if the caution is not being lit (NO in S11), ECU 1000 sets the lowering prevention driving force lower limit value to “FDb” (S13).

  On the other hand, when the motor output is being restricted (YES in S10) and the caution is being lit (YES in S11), ECU 1000 sets the lowering prevention driving force lower limit value to “FDa” lower than FDb (S12). ).

  FIG. 4 is a diagram exemplifying a map used for setting the lowering prevention driving force lower limit value. As shown in FIG. 4, the reverse drive force lower limit values FDa and FDb are both set to “0” when the vehicle speed V exceeds the predetermined speed V1, and the vehicle speed V when the vehicle speed V is less than the predetermined speed V1. The lower the value, the larger the value. For the same vehicle speed V, the reverse drive force lower limit value FDa during motor output restriction is set to a value lower than the reverse drive force lower limit value FDb during motor output non-restriction (before motor output restriction). . That is, during the motor output restriction, the guaranteed range of the vehicle driving force by the reverse prevention control is relaxed compared to before the motor output restriction.

  Returning to FIG. 3, after setting the lower limit drive force lower limit value in S12 or S13, the ECU 1000 determines whether or not the set lower limit drive force lower limit value can be guaranteed by the motor output (that is, the reverse drive force) It is determined whether or not the vehicle driving force equal to or greater than the lower limit value can be satisfied by the motor output (S14).

  When the lower limit drive force lower limit value can be guaranteed by the motor output (YES in S14), ECU 1000 guarantees the lower limit drive force lower limit value by the motor output (S15). That is, ECU 1000 controls second MG 400 so as to ensure that the actual vehicle driving force is equal to or higher than the set lowering prevention driving force lower limit value.

  On the other hand, if the lower limit drive force lower limit value cannot be guaranteed by the motor output (YES in S14), ECU 1000 ensures the lower limit drive force lower limit value by compensating the shortage of the motor output with engine direct torque Tep ( S16).

As described above, ECU 1000 according to the present embodiment reduces the lower limit drive force lower limit value during motor output restriction than before motor output restriction (relaxes the guaranteed range of vehicle drive force by reverse prevention control). . When the lowering prevention driving force lower limit after the reduction cannot be satisfied by the motor output, the shortage is compensated by the output of the engine 100. Thereby, even when the motor output is being limited, the output of the engine can be suppressed to the minimum necessary while ensuring the necessary driving force. Therefore, excessive fluctuations and overheating of the engine speed can be suppressed.
<Modification 1 of Embodiment 1>
FIG. 5 is a flowchart showing a first modified example of guarantee relaxation control.

  The flowchart of FIG. 5 according to the first modification is obtained by adding the process of S20 to the flowchart of FIG. 3 according to the first embodiment. In the present modification, the description of the process of S11 is omitted for convenience of description. The process itself of S11 may be omitted.

  In the flowchart of FIG. 3 according to the first embodiment, ECU 1000 reduces the lower limit drive force lower limit value when the motor output is being restricted (YES in S10) (S12).

  On the other hand, in the flowchart of FIG. 5 according to the present modification, ECU 1000 determines whether or not the engine is starting when the motor output is being restricted (YES in S10) (S20).

  When the motor output is not being restricted (NO at S10) or when the engine is not being started (NO at S20), ECU 1000 uses the map of FIG. 4 described above to set the reverse drive force lower limit value to “FDb”. "(S13).

  On the other hand, when the motor output is being limited (YES in S10) and engine 100 is being started (YES in S20), ECU 1000 uses the map shown in FIG. It is reduced to “FDa” lower than FDb (S12).

As described above, in the first modification, it is possible to preferentially secure the torque consumed for starting the engine by reducing the guaranteed driving force when starting the engine. Therefore, stable engine start is possible, and engine startability can be improved.
<Modification 2 of Embodiment 1>
FIG. 6 is a flowchart showing a second modification of the guarantee relaxation control. Of the steps shown in FIG. 6, the steps given the same numbers as the steps shown in FIG. 5 described above have already been described, and detailed description thereof will not be repeated here. In this modification as well, the description of the process of S11 is omitted for convenience of description. The process itself of S11 may be omitted.

  If the motor output is not being restricted (NO in S10), ECU 1000 sets the reverse drive force lower limit value to “FDb” (S34).

  If the motor output is being limited (YES in S10) but not at the time of engine start (NO in S20), ECU 1000 sets the reverse drive force lower limit value to “FDa1” lower than FDb (S33). .

  When the motor output is being restricted (YES in S10) and the engine is being started (YES in S20), ECU 1000 sets the reverse drive force lower limit value to “FDa2”, which is lower than FDa1 (S32). ).

  FIG. 7 is a diagram exemplifying a map used for setting the lowering prevention driving force lower limit value in the second modification. As shown in FIG. 7, the reverse drive force lower limit values FDa1, FDa2, and FDb are all set to “0” when the vehicle speed V exceeds the predetermined speed V2, and within the range where the vehicle speed V is less than the predetermined speed V2. The lower the vehicle speed V, the larger the value is set. For the same vehicle speed V, the reverse prevention driving force lower limit value FDa1 is set to a value lower than the reverse prevention driving force lower limit value FDb, and the reverse prevention driving force lower limit value FDa2 is further lower than the reverse prevention driving force lower limit value FDa1. Set to a low value.

  That is, during the motor output restriction, the guaranteed range of the vehicle driving force by the reverse prevention control is relaxed compared to before the motor output restriction. Further, when the engine is started while the motor output is limited, the guaranteed range is further relaxed than when the engine is not started.

As described above, in the second modification, in addition to lowering the guaranteed driving force while the motor output is limited, the reduction amount (relaxation amount) of the guaranteed driving force when starting the engine is set to the guaranteed driving when the engine is not started. Make it greater than the amount of force reduction (relaxation). This makes it possible to start the engine more stably while minimizing the engine output.
[Embodiment 2]
In the first embodiment described above, the mitigation target by the guarantee mitigation control is set as the “reverse prevention driving force lower limit value”.

  On the other hand, in the second embodiment, the target of the guaranteed driving force that is relaxed by the “guaranteed relaxation control” is the “engine braking force lower limit value”. Since other structures, functions, and processes are the same as those in the first embodiment, detailed description thereof will not be repeated here.

  FIG. 8 is a flowchart showing the processing contents of guarantee relaxation control performed by ECU 1000 according to the second embodiment. In FIG. 8, the same steps as those shown in FIG. 6 are given the same step numbers. The processing for them is the same. Therefore, detailed description thereof will not be repeated here.

  In S40, ECU 1000 determines whether or not a motor output restriction condition is satisfied. For example, ECU 1000 determines that the motor output restriction condition is satisfied when at least one of the following conditions A, B, C, and D is satisfied.

  (Condition A) The amount of power stored in the battery 700 is higher than a predetermined control upper limit value (that is, it is necessary to limit charging to the battery 700).

(Condition B) The temperature THm2 of the second MG 400 is higher than the threshold temperature.
(Condition C) The inverter temperature THi is higher than the threshold temperature.

(Condition D) Boost converter temperature THc is higher than a threshold temperature.
The motor output restriction conditions are not limited to the above conditions. For example, when the transmission is provided between the second MG 400 and the drive wheel 82, a condition that the temperature of the transmission is higher than the threshold temperature may be added.

  ECU 1000 sets the engine brake force lower limit value to “FBb” when the motor output restriction condition is not satisfied (NO in S40) or when the caution is not lit (NO in S11) (S44).

  ECU 1000 sets the engine braking force lower limit value to “FBa1” lower than FBb when the motor output restriction condition is satisfied (YES in S40) and not when the engine is started (NO in S20). (S43).

  When the motor output restriction condition is satisfied (YES in S40) and when the engine is being started (YES in S20), ECU 1000 sets the engine brake force lower limit value to “FBa2” that is lower than FBa1. Set (S42).

  FIG. 9 is a diagram illustrating a map used for setting the engine braking force lower limit value in S42 to S44. As shown in FIG. 9, the engine braking force lower limit values FBa1, FBa2, and FBb are all set to “0” when the vehicle speed V is less than the predetermined speed V3, and the vehicle speed is within the range where the vehicle speed V exceeds the predetermined speed V3. The higher V is, the larger the value is set. For the same vehicle speed V, the engine brake force lower limit value FBa1 is set to a value lower than the engine brake force lower limit value FBb, and the engine brake force lower limit value FBa2 is set to a value lower than the engine brake force lower limit value FBa1. Is done.

  That is, during the motor output restriction, the braking force guaranteed range by the engine brake control is relaxed compared to before the motor output restriction. Further, when the engine is started while the motor output is limited, the guaranteed range is further relaxed than when the engine is not started.

  Returning to FIG. 8, after setting the engine braking force lower limit value in S42 to S44, ECU 1000 can guarantee the set engine braking force lower limit value by the motor output (regenerative braking force by second MG 400). Is determined (S45).

  If the engine brake force lower limit value can be guaranteed by the motor output (YES in S45), ECU 1000 guarantees the engine brake force lower limit value by the motor output (S46). That is, ECU 1000 controls the regenerative braking force by second MG 400 so as to ensure that the actual engine braking is equal to or higher than the set engine braking force lower limit value.

  On the other hand, when the engine brake force lower limit value cannot be guaranteed by the motor output (NO in S45), ECU 1000 compensates the shortage of the motor output with engine direct torque Tep (engine brake force by engine 100) to generate the engine brake force. A lower limit value is guaranteed (S47).

As described above, ECU 1000 according to the present embodiment lowers the engine brake force lower limit value during motor output restriction than before motor output restriction (relaxes the guaranteed range of engine brake). If the engine brake force lower limit after the reduction cannot be satisfied by the motor output (regenerative braking force by the second MG 400), the shortage is compensated by the engine output (engine braking force by the engine 100). As a result, even when the motor output is being limited, the engine output can be suppressed to the minimum necessary while ensuring the necessary braking force.
[Embodiment 3]
In the first embodiment described above, the mitigation target by the guarantee mitigation control is set as the “reverse prevention driving force lower limit value”.

  On the other hand, in the present third embodiment, the mitigation target by the guarantee mitigation control is set as “allowable driving force range at the time of engine start during traveling”. Since other structures, functions, and processes are the same as those in the first embodiment, detailed description thereof will not be repeated here.

  FIG. 10 is a flowchart showing the processing contents of guarantee relaxation control performed by ECU 1000 according to the third embodiment.

  In S50, ECU 1000 determines whether or not a motor output restriction condition is satisfied. For example, ECU 1000 determines that the motor output restriction condition is satisfied when at least one of the following conditions A ′, B, C, and D is satisfied.

  (Condition A ′) The amount of power stored in the battery 700 is lower than a predetermined control lower limit value (that is, it is necessary to limit discharge from the battery 700).

(Condition B) The temperature THm2 of the second MG 400 is higher than the threshold temperature.
(Condition C) The inverter temperature THi is higher than the threshold temperature.

(Condition D) Boost converter temperature THc is higher than a threshold temperature.
The motor output restriction conditions are not limited to the above conditions. For example, when the transmission is provided between the second MG 400 and the drive wheel, a condition that the temperature of the transmission is higher than the threshold temperature may be added.

  If the motor output restriction condition is satisfied (YES in S50), ECU 1000 determines whether or not the engine is being started during traveling (S51). For example, when there is a system activation request (Ready-ON request) while the vehicle is traveling in the Ready-OFF state, ECU 1000 determines that the engine is being started during traveling.

  If the motor output restriction condition is not satisfied (NO in S50) or not during running engine start (NO in S51), ECU 1000 sets the allowable driving force range at engine start to “β” (lower limit value βmin). To an upper limit value βmax) (S53).

  On the other hand, when the motor output restriction condition is satisfied (YES in S50) and when the engine is running while starting (YES in S51), ECU 1000 relaxes the allowable driving force range at the time of engine starting from β. “Α” (lower limit αmin to upper limit αmax) is set (S52).

  FIG. 11 is a diagram illustrating a map used for setting an allowable driving force range at the time of engine start in S52 or S53. In FIG. 11, the driving force is indicated by a positive value and the braking force is indicated by a negative value.

  As shown in FIG. 11, the allowable driving force ranges α and β at the time of starting the engine are expanded as the vehicle speed V is higher (the guaranteed range is relaxed). For the same vehicle speed V, the allowable driving force range α at the time of starting the engine while the motor output is being restricted and traveling is wider than the allowable driving force range β at the time of starting the engine at the normal time (before the motor output is restricted). (Warranty scope will be relaxed).

  Returning to FIG. 10, after setting the allowable driving force range at the time of starting the engine in S52 or S53, the ECU 1000 determines whether or not the set allowable driving force range at the time of starting the engine can be guaranteed by the motor output. (S54).

  If the allowable driving force range at the time of starting the engine can be guaranteed by the motor output (YES in S54), ECU 1000 guarantees the allowable driving force range at the time of starting the engine by the motor output (S55).

  On the other hand, if the allowable driving force range at the time of starting the engine cannot be guaranteed by the motor output (NO in S54), ECU 1000 compensates the shortage of the motor output by engine direct torque Tep and the allowable driving force range at the time of starting the engine. Is guaranteed (S56).

  As described above, when the motor output is being limited, ECU 1000 according to the present embodiment relaxes the allowable driving force range at the time of starting the engine while traveling more than usual. When the allowable driving force range after relaxation cannot be satisfied by the motor output (output of second MG 400), the shortage is compensated by the output of engine 100. As a result, even when the motor output is being limited, it is possible to suppress the output of the engine to the minimum necessary while suppressing fluctuations in the driving force when starting the engine while traveling.

  It should be noted that the above-described embodiments and modifications thereof can be combined as appropriate within a range where no technical contradiction arises.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Vehicle, 10 Engine rotational speed sensor, 15 Output shaft rotational speed sensor, 21, 22 Resolver, 31 Accelerator position sensor, 35 Start switch, 36 Gradient sensor, 37 Monitoring unit, 38 Caution lamp, 41-44 Temperature sensor, 56, 560 output shaft, 81 reduction gear, 82 drive wheel, 100 engine, 200 1st MG, 300 power split mechanism, 400 2nd MG, 600 PCU, 700 battery.

Claims (6)

A drive device including a first drive source and a second drive source, and configured to be able to transmit power of at least one of the first drive source and the second drive source to drive wheels;
A control device configured to be able to control the drive device,
When performing the predetermined vehicle behavior control, when the limit control for limiting the output of the first drive source to less than a predetermined value is being performed, the control device performs the drive apparatus more than before the limit control is performed. as well as of executing the relaxation control to relax the restriction of the output of the drive unit by braking lowering control lower limit value of the output can not meet the pre-Symbol lower control limit after relaxation at the output of the first drive source When the vehicle compensates for the shortage with the output of the second drive source. The second drive source includes an internal combustion engine,
The vehicle according to claim 1, wherein the control device executes the mitigation control when the restriction control is being executed and when the internal combustion engine is started. The first drive source is a rotating electrical machine,
In the vehicle behavior control, when the internal combustion engine is started while the vehicle is running, an output of the driving device is controlled by generating a force for canceling a reaction force generated by starting the internal combustion engine from the rotating electrical machine. Reaction force control to make within
The vehicle according to claim 2, wherein the relaxation control is control that widens a range of the control range by the reaction force control. The vehicle behavior control is a reverse prevention control for setting a reverse prevention driving force for preventing the vehicle from retreating to a lower limit value or more,
The vehicle according to any one of claims 1 to 3, wherein the relaxation control is control for reducing the lower limit value by the reverse prevention control. The vehicle behavior control is a braking control for setting a braking force acting on the driving wheel by a rotational resistance of the driving device to be a lower limit value or more.
The vehicle according to any one of claims 1 to 3, wherein the relaxation control is control for reducing the lower limit value by the braking control. The second drive source includes an internal combustion engine,
The controller, when executing the relaxation control, a change amount before Symbol lower control limit at the start of the internal combustion engine, is larger than the change amount before Symbol lower control limit in the non-starting of the internal combustion engine The vehicle according to claim 1.

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