Vehicle control device

Abstract

To stabilize the behavior of a hybrid vehicle in cutting and restoring of a creep torque and make a vehicle perform a behavior in line with a driver's intent.SOLUTION: A vehicle control device in an embodiment includes a control unit for cutting a creep torque after keeping generation of the creep torque for a prescribed time after the vehicle reached a prescribed stop state with an accelerator in an off state and a brake in an on state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] 2. Description of the Related Art In recent years, hybrid vehicles equipped with two types of power sources, an electric motor and an internal combustion engine, have become known. In a series hybrid vehicle, an internal combustion engine drives a motor generator to generate electricity, which is stored in a power storage device (battery or capacitor) and supplied to a traction motor generator connected to the tire axle via a reduction gear, and the vehicle is propelled by rotating the drive wheels with the traction motor generator.

[0003] In this series type hybrid vehicle, when creep driving is performed by generating creep torque with the driving motor generator, it is possible to drive the vehicle using only the output from the power storage device.

[0004] However, when a series hybrid vehicle is stopped and the driver intends to brake but not to accelerate, i.e., when the rotation speed of the hybrid vehicle's driving motor generator is below a predetermined stop threshold, the brake is on, and the accelerator is off (accelerator opening = 0 percent), generating creep torque will waste power from the storage device, which may result in a deterioration in fuel efficiency.

[0005] For this reason, a configuration was adopted in which creep torque is cut when the rotation speed of the hybrid vehicle's driving motor generator is below a predetermined stop threshold, the brake is on, and the accelerator is off (accelerator opening = 0 percent). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-320850 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above configuration, the rotation speed of the driving motor generator is not zero, so the creep torque on the acceleration side is suddenly cut, which effectively increases the braking force, causing nose dive and what is known as sudden braking, resulting in a poor ride.

[0008] Furthermore, although the tires are stopped and the rotation speed of the traction motor generator is zero, the driving force is not absent, so twisting occurs in the crankshaft. When the creep torque is cut, a force acts in the direction of eliminating the twist in the crankshaft, and the rotation speed of the traction motor generator may exceed a predetermined stop threshold. This may result in the hybrid vehicle being determined to be in a running state, and control to restore the creep torque may be activated again, potentially resulting in a hunting state.

[0009] Furthermore, if the creep torque is suddenly restored, sudden acceleration may occur, which may cause anxiety for the driver. However, if the increase in creep torque is limited to prevent this, the driver may lose the feeling of acceleration even in situations where they want to accelerate.

[0010] The present invention has been made in consideration of the above, and aims to provide a vehicle control device that can stabilize the behavior of a hybrid vehicle when cutting and restoring creep torque, and cause the vehicle to behave in accordance with the driver's intentions. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems and achieve the object, a vehicle control device according to an embodiment includes a control unit that cuts off the creep torque after maintaining the generation of the creep torque for a predetermined time after the vehicle reaches a predetermined stop state with the accelerator in an off state and the brake in an on state. The control unit maintains the generation of the creep torque, reduces the creep torque by a first change amount, and then cuts the creep torque; when the accelerator is in an off state and the brake is in an off state, restores the creep torque using a second change amount, the absolute value of which is set to be larger than the absolute value of the change amount per unit time of the first change amount at the time of cutting the creep torque; and when restoring the creep torque after cutting the creep torque, increases the creep torque by a third change amount larger than the second change amount if the opening of the accelerator is equal to or larger than a predetermined opening. .

[0012] This configuration prevents sudden torque loss, suppresses nose dive when the vehicle stops, improves ride comfort, and eliminates unnecessary maintenance of creep torque, reducing power consumption in electric or hybrid vehicles.

[0013] Also ,child According to the configuration of (1), sudden torque loss can be more easily prevented and creep torque can be cut, thereby further improving the ride comfort.

[0014] Ma Ta,ko According to the configuration of (1), creep torque can be generated quickly when the creep torque is restored, thereby improving drivability.

[0015] Ma Ta,ko According to the configuration of (1), when the driver intends to accelerate, the vehicle can be made to behave in accordance with the driver's intention.

[0016] Also , embodiment When maintaining the generation of the creep torque for the predetermined time, the control unit of the vehicle control device according to the present invention maintains the creep torque at a constant value for a second predetermined period, and then gradually reduces the creep torque by a first change amount. According to this configuration, while the creep torque is maintained at a constant value for a second predetermined period, the creep torque can be cut while eliminating torsion in the drive system (crankshaft), thereby suppressing hunting in vehicle stop determination caused by torsion in the drive system and making the vehicle behavior stable in line with the driver's intentions.

[0017] Also, EmbodimentWhen the accelerator is in an on state and the brake is in an off state, the control unit of the vehicle control device according to the present invention increases the creep torque by a fourth change amount set to be larger than the third change amount. According to this configuration, when the driver's intention to accelerate is considered strong, an acceleration behavior that is in line with the driver's intention can be obtained. [Effects of the Invention]

[0018] The vehicle control device according to the present invention has the effect of preventing sudden torque loss, suppressing nose dive when the vehicle stops, improving ride comfort, and eliminating unnecessary maintenance of creep torque, thereby suppressing power waste. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a hybrid vehicle to which a vehicle control device according to this embodiment is applied. [Figure 2] FIG. 2 is a processing flowchart of the ECU according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram of an example of an operation timing chart according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram of an operation timing chart of the first comparative example. [Figure 5] FIG. 5 is an explanatory diagram of an operation timing chart of the second comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0020] An example of a vehicle control device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a hybrid vehicle to which a vehicle control device according to this embodiment is applied.

[0021] The hybrid vehicle 10 comprises an internal combustion engine 11, a power generating motor generator 12 driven by the internal combustion engine 11 to generate electricity, a storage device 13 that stores the electricity generated by the power generating motor generator 12, a power control unit (PCU) 14 that performs power control such as frequency conversion and power conversion, a driving motor generator 15 that receives power from at least one of the power generating motor generator 12 and the storage device 13 via the PCU 14 and drives the vehicle's drive wheels 22 via a reduction gear 21, and an ECU 16.

[0022] The hybrid vehicle 10 of this embodiment is a series hybrid electric vehicle that uses the internal combustion engine 11 only for generating electricity. Therefore, the driving force for running is supplied to the drive wheels 22 of the hybrid vehicle 10 exclusively from the traction motor generator 15. The internal combustion engine 11 and the drive wheels 22 are mechanically separated, and no rotational drive force is transmitted between the internal combustion engine 11 and the drive wheels 22. In other words, the internal combustion engine 11 can rotate completely independently of the traction motor generator 15 and the drive wheels 22.

[0023] Therefore, when the hybrid vehicle 10 is in operation with the ignition switch (power switch or ignition key) turned on, even if the driver (operator) steps on the accelerator (pedal) to allow the vehicle to run, the internal combustion engine 11, which involves burning fuel, may not be driven if the storage device 13 has stored sufficient power.

[0024] The internal combustion engine 11 is, for example, a four-stroke engine including multiple cylinders. A crankshaft, which is a rotating shaft of the internal combustion engine 11, is mechanically connected to a rotating shaft of the power-generating motor-generator 12 via a gear mechanism. The rotational driving force output by the internal combustion engine 11 is input to the power-generating motor-generator 12, causing the power-generating motor-generator 12 to generate electricity.

[0025] The electric power generated by the power generation motor generator 12 is charged into the power storage device 13 via the PCU 14, or is supplied to the traveling motor generator 15. The power generation motor generator 12 also functions as an electric motor that generates a rotational driving force to rotate the crankshaft of the internal combustion engine 11. For example, the power generation motor generator 12 performs motoring (cranking) in preparation for starting the internal combustion engine 11 that is in a stopped state.

[0026] The traction motor generator 15 generates driving force for driving the hybrid vehicle 10 and inputs the driving force to the drive wheels 22 via the reduction gear 21. The traction motor generator 15 also generates electricity by rotating in conjunction with the rotation of the drive wheels 22, thereby performing regenerative braking to recover the kinetic energy of the hybrid vehicle 10 as electrical energy. The electric power generated by this regenerative braking is supplied to the power storage device 13 and charged therein.

[0027] In addition, when the storage device 13 has already stored electricity to its full capacity and further charging is difficult, the electric power generated by the driving motor generator 15 through regenerative braking is supplied to the power generation motor generator 12 via the PCU 14, and the power generation motor generator 12 is operated as an electric motor to rotate and drive the internal combustion engine 11.

[0028] This allows the surplus electric power to be consumed while maintaining the braking performance of the hybrid vehicle 10. At this time, the rotation of the internal combustion engine 11 is maintained, so a fuel cut can be performed to temporarily stop the supply of fuel to the internal combustion engine 11.

[0029] The PCU 14 includes an inverter 14A that performs power conversion corresponding to the power generation motor generator 12, and an inverter 14B that performs power conversion corresponding to the travel motor generator 15. Inverter 14A converts AC power generated by power generation motor generator 12 into DC power, and supplies the DC power to power storage device 13 or inverter 14B.

[0030] Furthermore, when the power generating motor generator 12 is operated as a motor (electric motor), the inverter 14A converts DC power supplied from the power storage device 13 or the inverter 14B into AC power and supplies it to the power generating motor generator 12.

[0031] On the other hand, inverter 14B converts DC power supplied from power storage device 13 or inverter 14A into AC power and supplies it to motor generator 15 for driving. Furthermore, inverter 14B converts AC power generated by traveling motor generator 15 into DC power when regenerative braking of the vehicle is performed, and supplies the DC power to power storage device 13 or inverter 14A.

[0032] The power storage device 13 is composed of a battery, a capacitor, and the like. The power storage device 13 is charged with and stores the electric power generated by the power generation motor generator 12 and the traction motor generator 15, respectively. The power storage device 13 also supplies (discharges) the electric power required to operate the power generation motor generator 12 and the traction motor generator 15 as electric motors.

[0033] The ECU 16 controls the internal combustion engine 11, the power generation motor generator 12, the electricity storage device 13, the PCU 14 (inverters 14A, 14B), and the driving motor generator 15. The ECU 16 is a microcomputer system that includes a microprocessor, a memory, an input interface, an output interface, and the like. The ECU 16 is composed of multiple ECUs, namely, an engine controller 16A that controls the internal combustion engine 11, a generator controller 16B that controls the power generation motor generator 12 and the inverter 14A, a battery controller 16C that controls the power storage device 13, and a drive unit controller 16D that functions as a control unit and controls the driving motor generator 15 and the inverter 14B, which are connected to each other so that they can communicate with each other via a communication network NET such as a CAN (Controller Area Network).

[0034] In the above configuration, the ECU 16 performs sensing via a group of sensors (not shown).

[0035] The sensors constituting the sensor group (not shown) include a sensor that senses the accelerator opening operated by the driver, i.e., the amount of depression of the accelerator pedal, a sensor that detects the shift position, i.e., the position of the shift lever or selector lever, a sensor that detects the on / off state of a switch, sensors such as an acceleration sensor that detects the current vehicle speed, sensors such as a gyro sensor that detects the gradient of the road surface, sensors such as a voltage sensor that detects the amount of electricity stored in the electricity storage device 13, and a sensor that detects the generated power of the power generating motor generator 12.

[0036] Based on the outputs of the sensors, the ECU 16 controls the rotational driving force of the traveling motor generator 15, the rotational driving force of the internal combustion engine 11, the magnitude of the electric power generated by the electric power generating motor generator 12, and the like.

[0037] In addition, if the power storage device 13 currently stores sufficient power and the output required for the driving motor generator 15 is small, the ECU 16 controls the engine controller 16A to cut off the supply of fuel to the internal combustion engine 11 and not operate the internal combustion engine 11.

[0038] On the other hand, if the amount of electricity currently stored in the storage device 13 is below a predetermined amount, or if the output required for the driving motor generator 15 is large, the internal combustion engine 11 is started via the engine controller 16A, fuel is supplied and burned, and the internal combustion engine 11 drives the power generation motor generator 12, and under the control of the generator controller 16B, power is generated to charge the storage device 13, or the power supplied to the driving motor generator 15 is increased.

[0039] Next, the operation of the embodiment will be described. FIG. 2 is a processing flowchart of the ECU according to the embodiment. FIG. 3 is an explanatory diagram of an example of an operation timing chart according to the embodiment.

[0040] As shown in Figure 3, in the initial state, the driver's foot is off the accelerator pedal, the accelerator opening is 0%, the rotation speed of the driving motor generator 15 is gradually decreasing, the acceleration is constant, and the torque of the driving motor generator 15 is constant.

[0041] First, the ECU 16 calculates a target creep torque based on the accelerator opening and the rotation speed of the traveling motor generator 15 (step S11). Also, as shown in FIG. 3, when the driver of the hybrid vehicle 10 depresses the brake pedal to start braking at time t0, the pressure in the brake master cylinder (M / C pressure) rises sharply.

[0042] Then, when the driver maintains a constant amount of depression of the brake pedal, the pressure in the master cylinder of the brake (M / C pressure) becomes constant from time t1.

[0043] Then, at time t2, when the rotation speed of the driving motor generator 15 reaches the first stop threshold Rth1, the ECU 16 determines that the hybrid vehicle 10 is transitioning to a stopped state, but enters a standby state until the rotation speed of the driving motor generator 15 becomes equal to or lower than a predetermined second stop threshold Rth2.

[0044] At time t3, when the rotation speed of the traveling motor generator 15 becomes equal to or less than a predetermined second stop threshold Rth2, the driving machine controller 16D controls the traveling motor generator 15 to maintain the rotation speed of the traveling motor generator 15, and ultimately the torque generated by the traveling motor generator 15, constant.

[0045] Next, it is determined whether the rotation speed of the traveling motor-generator 15 has become equal to or less than the predetermined second stop threshold value Rth2 and a predetermined time Pt ​​has elapsed (step S12). This determination makes it possible to more reliably determine whether the hybrid vehicle 10 is stopped compared to when the determination is made based only on the rotation speed of the traveling motor-generator 15.

[0046] Furthermore, at time t3, when the rotation speed of the travel motor-generator 15 becomes equal to or lower than the predetermined second stop threshold Rth2, the torque generated by the travel motor-generator 15 is maintained constant, and the torsion of the crankshaft is kept constant. After that, by gradually cutting the creep torque, a force that tries to return the torsion of the crankshaft to its original state does not suddenly act, and the creep torque does not suddenly return, causing hunting.

[0047] At time t4, if it is determined in step S12 that a predetermined time Pt ​​has elapsed since the rotation speed of the traveling motor generator 15 became equal to or less than a predetermined stop threshold (step S12; Yes), that is, in the example of FIG. 3, it is determined whether the accelerator opening is 0% or not, that is, whether the driver of the hybrid vehicle 10 has performed an acceleration operation (step S13).

[0048] In the determination of step S13, if the accelerator opening is 0% (step S13; Yes), the driver of the hybrid vehicle 10 has not performed an acceleration operation, so it is determined whether the pressure in the master cylinder (M / C) of the brake system is above a predetermined value (brake on state), whether the brake is in a hold state or the electronic parking brake (EPB) is operating, i.e., whether a braking operation has been performed (step S14).

[0049] In the judgment of step S14, if the pressure of the master cylinder (M / C) of the brake system is equal to or greater than a predetermined value (brake on state), the brake is on hold, or the electronic parking brake (EPB) is activated (step S14; Yes), the hybrid vehicle 10 is stopped, no acceleration operation is being performed, and braking operation is being performed, and the prerequisites for cutting the creep torque are met, so the target creep torque is updated to 0 (Nm) (step S15).

[0050] Then, after time t4, the first gradual change process during creep torque cut is carried out (step S16). Here, the first gradual change process when the creep torque is cut means that the drive motor controller 16D as a control unit controls the traveling motor generator 15 to reduce the creep torque by a predetermined first change amount (torque reduction rate), and gradually reduces the creep torque to the target creep torque (0 (Nm) in this example) until no significant nose dive occurs even when the creep torque is cut.

[0051] In this case, the first amount of change is set to a rate of change such that the rotation speed of the traveling motor-generator 15 does not exceed a predetermined stop threshold when the twist of the crankshaft is released.

[0052] Furthermore, during the first gradual change process from time t4 to time t6 in FIG. 3 (while the vehicle is stopped), the drive machine controller 16D of the ECU 16 controls the travel motor generator 15 to suppress fluctuations in the rotation speed of the travel motor generator.

[0053] Then, at time t5, when the creep torque reaches the target creep torque, that state is maintained.

[0054] Similarly, until the driver stops depressing the brake pedal and releases the brake hold or the electronic parking brake, the creep torque state is maintained as at time t5, and the processing of steps S11 to S17 is repeated.

[0055] On the other hand, if it is determined in step S12 that the rotation speed of the driving motor generator 15 is below a predetermined stop threshold and the predetermined time Pt ​​has not elapsed (step S12; No), if it is determined in step S13 that the accelerator opening is not 0% (step S13; No), or if it is determined in step S14 that the pressure in the master cylinder (M / C) of the brake system is below a predetermined value (brake off state), the brake is not in a hold state, and the electronic parking brake (EPB) is not activated (step S14; No), it is determined whether the accelerator opening is below a predetermined opening (step S18).

[0056] Here, the predetermined opening is set to an opening at which it is estimated that the driver is depressing the accelerator pedal and that the driver's intention to accelerate is clear. If the determination in step S18 is that the accelerator opening is equal to or less than a predetermined opening (step S18; Yes), it is assumed that the driver's intention to accelerate is not clear, so the increase in creep torque when the creep torque is restored is limited, and a second gradual change process is performed when the creep torque is restored to prevent disturbance in the vehicle behavior of the hybrid vehicle 10 (step S19).

[0057] Here, the second gradual change process when the creep torque is restored means that the driving machine controller 16D as a control section controls the traveling motor generator 15 to increase the creep torque at a predetermined second change amount (torque increase rate).

[0058] Here, the second change amount has a positive value (increase) and the first change amount has a negative value (decrease), but the absolute value of the gradient of the second change amount is greater than the absolute value of the gradient of the first change amount, so that the creep torque increases more quickly than when the creep torque decreases, allowing the driver to feel that the creep torque has been generated immediately, thereby improving drivability. However, this second change amount is set to have a smaller gradient than the conventional change amount when creep torque is generated (increased) as shown by the dashed line in Figure 3, so that the change in acceleration is suppressed, improving drivability while preventing a deterioration in ride comfort.

[0059] Thereafter, the driving machine controller 16D instructs the traveling motor generator 15 to generate creep torque after the second gradual change process so that the generated creep torque becomes the target creep torque (step S20).

[0060] On the other hand, if the accelerator opening exceeds the predetermined opening in the judgment of step S18 (step S18; No), it is assumed that the driver's intention to accelerate is clear. However, if acceleration or deceleration is performed corresponding to the accelerator opening, sudden acceleration or deceleration may occur. Therefore, it is desirable to limit the increase amount (increase rate) of the creep torque when the creep torque is restored, and prevent disturbance of the vehicle behavior of the hybrid vehicle 10.

[0061] Therefore, a third gradual change process is carried out to prevent sudden acceleration and deceleration (step S21). Here, the third gradual change process means that the driving machine controller 16D as a control section controls the traveling motor generator 15 to increase the creep torque at a predetermined third change amount (torque increase rate).

[0062] In this case, the third change amount is set to be even larger than the second change amount, so that the driver can feel that creep torque has been generated immediately, thereby improving drivability.

[0063] Thereafter, the driving machine controller 16D instructs the traveling motor generator 15 to generate creep torque after the second gradual change process so that the generated creep torque becomes the target creep torque (step S22).

[0064] As described above, according to this embodiment, after the hybrid vehicle 10 comes to a stop, the creep torque is maintained for a predetermined period of time and then cut. This prevents a sudden loss of torque and does not unnecessarily maintain the creep torque, thereby suppressing an increase in unnecessary power consumption, thereby improving drivability and fuel economy.

[0065] Furthermore, when the creep torque is cut, the amount of change (rate of change) of the creep torque is limited, thereby preventing the vehicle behavior from becoming unstable, such as the occurrence of a sudden nose dive.

[0066] On the other hand, when the creep torque is restored, the driver can feel the return of the creep torque and, in order to suppress disturbances in vehicle behavior, the absolute value of the amount of change (rate of change) per unit time when the creep torque is restored is made larger than the absolute value of the amount of change (rate of change) per unit time when the creep torque is cut.Therefore, when the creep torque is restored and is needed immediately, the creep torque can be generated immediately, thereby improving drivability.

[0067] Furthermore, when the creep torque is restored, if the accelerator opening is equal to or greater than a predetermined opening where the driver's intention to accelerate is clear, the amount of change (rate of change) of the creep torque is set to be even larger, thereby realizing acceleration in line with the driver's intention and further improving drivability.

[0068] [Comparative Example] Next, the effects of the vehicle control device according to this embodiment will be described in comparison with a vehicle control device system according to a comparative example.

[0069] [First Comparative Example] FIG. 4 is an explanatory diagram of an operation timing chart of the first comparative example. The device configuration of the vehicle control device is the same as that of the embodiment, and therefore, in the following description, the names of the various parts of the device will be those of the first embodiment.

[0070] As shown in Figure 4, in the initial state, the driver's foot is off the accelerator pedal, the accelerator opening is 0%, the rotation speed of the driving motor generator 15 is gradually decreasing, the acceleration is constant, and the torque of the driving motor generator 15 is constant.

[0071] As shown in FIG. 4, when the driver of the hybrid vehicle 10 depresses the brake pedal to start braking at time t10, the pressure in the brake master cylinder (M / C pressure) rises sharply.

[0072] Then, when the driver maintains a constant amount of depression of the brake pedal, from time t11 onwards, the pressure in the master cylinder of the brake (M / C pressure) becomes constant. Then, at time t12, when the rotation speed of the traveling motor generator 15 reaches the stop threshold value Rth, the driving machine controller 16D of the ECU 16 cuts the creep torque.

[0073] This results in a sudden change in acceleration, a noticeable nose dive, and a sudden braking.

[0074] Furthermore, at time t13, when the driver stops pressing the brake pedal and the pressure in the master cylinder (M / C) of the brake system falls below a predetermined value (brake-off state), if the same creep torque generation control is performed when the driver intends to accelerate (accelerator on) and when the driver does not intend to accelerate (accelerator off), the drive motor controller 16D will immediately generate creep torque after the first gradual change processing in the driving motor generator 15, which will result in a deterioration in ride comfort due to sudden acceleration. Then, at time t14, when the generated creep torque reaches the target creep torque, this state is maintained.

[0075] As explained above, it can be seen that, according to the embodiment, the change in acceleration can be made smaller than in the first comparative example, and significant nose dive can be suppressed. Furthermore, according to the embodiment, even when the creep torque returns, there is no change in acceleration due to the sudden return of the creep torque, compared to the first comparative example, and therefore it can be seen that the ride comfort and drivability are improved.

[0076] [Second Comparative Example] FIG. 5 is an explanatory diagram of an operation timing chart of the second comparative example. The device configuration of the vehicle control device is the same as that of the embodiment, and therefore, in the following description, the names of the various parts of the device will be those of the first embodiment.

[0077] As shown in Figure 5, in the initial state, the driver's foot is off the accelerator pedal, the accelerator opening is 0%, the rotation speed of the driving motor generator 15 is gradually decreasing, the acceleration is constant, and the torque of the driving motor generator 15 is constant.

[0078] As shown in FIG. 5, when the driver of the hybrid vehicle 10 depresses the brake pedal to start braking at time t20, the pressure in the brake master cylinder (M / C pressure) rises sharply.

[0079] Then, when the driver maintains a constant amount of depression of the brake pedal, from time t21 onwards, the pressure in the master cylinder of the brake (M / C pressure) becomes constant. Then, at time t22, the creep torque generated by the traveling motor generator 15 is cut while the rotation speed of the traveling motor generator 15 is reduced.

[0080] However, at time t22, the torsion of the drive shaft has not been released, so the driving motor generator 15 is driven in a direction that releases the torsion of the crankshaft, i.e., in the rotation direction when the vehicle is running. This overturns the stop determination and determines that the vehicle is running. At time t23, the creep torque returns, resulting in a hunting state, which reduces both ride comfort and drivability.

[0081] As described above, according to the embodiment, compared to the second comparative example, the transition to a hunting state in which creep torque returns does not occur as the twist of the crankshaft is eliminated, thereby improving ride comfort and drivability.

[0082] Furthermore, as in the first comparative example, even when the creep torque returns after time t24, there is no change in acceleration due to the sudden return of the creep torque, and therefore it can be seen that the ride comfort and drivability are improved.

[0083] In the above explanation, the case where the accelerator is in the off state has been mainly described, but when the accelerator is in the on state and the brake is in the off state, the driving machine controller 16D functioning as a control unit can also respect the driver's intention to accelerate more and increase the creep torque by a fourth change amount set larger than the third change amount described above. This configuration allows the driver to perform acceleration operations more in line with his or her intentions, thereby improving drivability. [Explanation of symbols]

[0084] 10 Hybrid vehicles 11 Internal combustion engine 12. Power generating motor generator 12. Drive motor generator 13. Energy storage device 14 PCU 14A, 14B inverter 15. Drive motor generator 16 ECU 16A Engine Controller 16B Generator Controller 16C Battery Controller 16D drive controller 21 Reducer 22 Drive wheels NET Communication Network Pt Predetermined time Rth Stop threshold Rth1 First stop threshold Rth2 Second stop threshold

Claims

1. a control unit that controls the motor generator, causes the motor generator to maintain generation of creep torque for a predetermined time after the vehicle has reached a predetermined stop state with the accelerator pedal in an off state and the brake in an on state, and then cuts the creep torque; the control unit maintains generation of the creep torque, reduces the creep torque by a first change amount, and then cuts the creep torque; When the accelerator is in an off state and the brake is in an off state, the creep torque is restored using a second change amount, the absolute value of which is set to be larger than the absolute value of the change amount per unit time of the first change amount when the creep torque is cut off, When the creep torque is restored after the creep torque is cut, if the opening degree of the accelerator is equal to or greater than a predetermined opening degree, the creep torque is increased by a third change amount that is larger than the second change amount. Vehicle control device.

2. When maintaining the generation of the creep torque for the predetermined time, the control unit maintains the creep torque at a constant value for a second predetermined period, and then gradually reduces the creep torque by a first change amount. The vehicle control device according to claim 1 .

3. the control unit increases the creep torque by a fourth change amount set to be larger than the third change amount when the accelerator is in an on state and the brake is in an off state. The vehicle control device according to claim 1 .

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