JP2014208498A - Vehicle controller - Google Patents

Abstract

A vehicle control device that stabilizes vehicle behavior even when an abnormality occurs in a regenerative brake. A vehicle control device calculates a target behavior of a vehicle based on a brake pedal operation amount or an accelerator pedal operation amount (S402, S404). When the difference between the target deceleration acceleration calculated from the driving operation amount and the deceleration acceleration detected by the G sensor exceeds a predetermined range (S406: Yes), the vehicle control device determines the control device that controls the motor generator. Based on the result, an abnormality of the regenerative brake is detected (S410), and a normal friction brake other than the regenerative brake is used to compensate for the reduced torque due to the braking force generated by the abnormal regenerative brake, and to achieve the target behavior. Torque generated by the entire vehicle is distributed to the engine and transmission (412). The vehicle control device commands the motor generator to be electrically disconnected from the vehicle, and ends the torque compensation control (S414). [Selection] Figure 2

Description

  The present invention relates to a vehicle control device applied to a vehicle that obtains braking force using a friction brake and a regenerative brake.

  Conventionally, for example, in a hybrid vehicle, a friction brake that presses a friction member against a rotating wheel by hydraulic pressure such as hydraulic pressure to convert kinetic energy into heat energy and generate braking force, and driving force for driving the vehicle are generated. A technique is known in which a braking force is obtained using a regenerative brake that generates a braking force by operating a motor generator used as an electric motor as a generator (see, for example, Patent Document 1).

  While the vehicle is traveling, the target behavior of the vehicle as a whole is set for vehicle behavior such as vehicle speed, acceleration, and vehicle inclination, based on the driving state of the driver, the road surface condition, and the like. In order to realize the target behavior set for the entire vehicle, control targets such as a motor generator, a friction brake, an injector, a throttle device, and a transmission are controlled so as to have individual target control amounts.

JP 2009-262836 A

  Normally, in order to realize the target behavior as a whole vehicle, each control object is controlled to have a respective target control amount, and operates according to the target control amount. However, for example, when the regenerative brake is locked, even if control is performed so that the regenerative brake becomes the target control amount, a large braking force may be generated by the regenerative brake, and the vehicle may decelerate.

  If a large braking force is generated regardless of the driving operation of the vehicle and the vehicle decelerates, the driver may depress the accelerator pedal to increase the vehicle speed while feeling uneasy. On the other hand, as a process of the control device that controls the regenerative brake, it can be considered that when an abnormality occurs that the regenerative brake is locked, the abnormal regenerative brake is disconnected so that the braking force due to the regenerative brake is not generated.

  If the driver depresses the accelerator pedal to eliminate the braking force that occurs regardless of the driving operation due to the regenerative brake abnormality, the vehicle suddenly turns off when the controller releases the regenerative brake and releases the regenerative braking force. Accelerate to. Then, an uneasy driver depresses the brake pedal in an attempt to suppress the rapid acceleration of the vehicle.

  As described above, when the driver performs the accelerator operation and the brake operation due to the abnormality of the regenerative brake, the vehicle behavior becomes unstable and the driver may not be able to perform an appropriate driving operation.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle control device that stabilizes the vehicle behavior even when an abnormality occurs in the regenerative brake.

  The vehicle control device of the present invention is a vehicle control device applied to a vehicle that obtains braking force using a friction brake and a regenerative brake, and when the abnormality detection means detects an abnormality of the regenerative brake, the regenerative stop means Before releasing the regenerative brake, the behavior control unit controls the actual behavior so as to match the target behavior based on the difference between the target behavior of the vehicle set by the behavior setting unit and the actual behavior.

  According to this configuration, even if a difference occurs between the target behavior and the actual behavior of the vehicle due to an increase or decrease in the braking force due to the regenerative brake due to an abnormality occurring in the regenerative brake, before the regenerative brake is disconnected, The actual behavior is controlled to match the target behavior.

  If the braking force of the regenerative brake increases due to regenerative brake abnormality, for example, in a hybrid vehicle, if the internal combustion engine is a gasoline engine, increase the intake air amount, and if it is a diesel engine, increase the injection amount of the injector. It is conceivable that the vehicle control device performs behavior control such as increasing the torque generated by the internal combustion engine.

  In an electric vehicle, for example, if a plurality of motor generators are provided as drive sources, it is conceivable that the vehicle control device performs behavior control such as increasing the torque generated by a normal motor generator.

  Also, when the braking force of the regenerative brake decreases due to an abnormality in the regenerative brake, in a hybrid vehicle, for example, if the internal combustion engine is a gasoline engine, the intake air amount is reduced, and if it is a diesel engine, the injection amount of the injector is decreased. It is conceivable that the vehicle control device performs behavior control such as decreasing the generated torque of the internal combustion engine.

  If a part of the operation of the regenerative brake can be controlled even if an abnormality occurs in the regenerative brake, not only the control target other than the regenerative brake but also the regenerative brake is controlled. The actual behavior may be controlled so as to match the target behavior.

  In this way, even if an abnormality occurs in the regenerative brake, the actual behavior is controlled so that it matches the target behavior before the regenerative brake is disconnected. Even if changes, the vehicle behavior can be returned to the target behavior and the vehicle behavior can be stabilized. As a result, even if an abnormality occurs in the regenerative brake, it is possible to prevent the driver from rushing and performing a driving operation such as an accelerator operation or a brake operation.

The block diagram which shows the vehicle control system by this embodiment. The flowchart which shows the behavior control process of a vehicle. The time chart which shows behavior control when abnormality generate | occur | produces in a regenerative brake.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Vehicle control system]
A vehicle control system 2 shown in FIG. 1 is a vehicle control system applied to, for example, a hybrid vehicle. The hybrid vehicle of the present embodiment uses a gasoline engine, which is an internal combustion engine (hereinafter also simply referred to as “engine”), and a motor generator that is rotationally driven by electric power supplied from a battery. For example, a DC brushless motor is used as the motor generator. A diesel engine may be mounted as the internal combustion engine.

  The vehicle control system 2 includes a brake ECU (BRKECU) 10, an engine ECU (ENGECU) 20, a motor generator ECU (MGECU) 30, a transmission ECU (TMECU) 40, and a hybrid ECU (HVECU) 50. .

  The BRK ECU 10 adjusts the hydraulic pressure generated by the electric pump with a solenoid valve or the like based on the operation amount of the driver with respect to the brake pedal 100, thereby controlling the hydraulic pressure pressing the friction member against the wheel to control the braking force of the friction brake. . Further, the BRK ECU 10 performs ABS (Anti-lock Brake System) control for controlling the hydraulic pressure applied to the friction brake so that the tire does not lock.

The ENGECU 20 controls the torque generated when the engine burns fuel by controlling the fuel injection, ignition timing, intake air amount, and the like of the injector.
When the motor generator operates as an electric motor, the MGECU 30 controls the torque generated by the motor generator by controlling the switching of the inverter. When the motor generator operates as a generator, the MGECU 30 controls the electric power generated by the motor generator, that is, the braking force of the regenerative brake generated by the motor generator.

  The TMECU 40 controls the hydraulic pressure applied to the clutches and brakes, which are friction engagement elements constituting the transmission, according to the operation of the shift lever by the driver and the traveling state of the vehicle, and sets the transmission gear stage.

  The HVECU 50 calculates the target behavior of the vehicle behavior during traveling based on the driving operation performed by the driver on the brake pedal 100 and the accelerator pedal 102 and the traveling state of the vehicle detected by the acceleration sensor (G sensor) 104. Then, the torque generated as a whole of the vehicle is distributed to the friction brake, engine, motor generator, and transmission so that the calculated target behavior is obtained, and commands are issued to the BRK ECU 10, ENGECU 20, MGECU 30 and TMECU 40 so that the distributed torque is obtained. .

  The ECUs BRKECU 10, ENGECU 20, MGECU 30, and TMECU 40 each control the corresponding control object according to the torque distributed from the HVECU 50.

  For example, when the driver depresses the brake pedal 100, the HVECU 50 calculates a target braking force based on an operation amount with respect to the brake pedal 100. Then, the HVECU 50 distributes the target braking force so that the total braking force generated by the friction brake and the regenerative brake becomes the target braking force, and commands the BRK ECU 10 and the MGECU 30.

  Further, when an abnormality such as a lock occurs when the motor generator operates as a regenerative brake and the HVECU 50 has a difference between the target behavior and the actual behavior of the vehicle, the HVECU 50 And distributes the compensation torque to the ENGECU 20 and the TMECU 40.

  The abnormality of the regenerative brake occurs, for example, when a fixed magnetic field is generated in the stator of the motor generator due to an abnormality in energization, and the rotation of the rotor is prevented and locked. In this case, HVECU 50 instructs MGECU 30 to electrically disconnect the abnormal motor generator from the vehicle.

  In addition, the regenerative brake abnormality also occurs when the rotor is prevented from rotating and locked due to foreign matter biting into the rotating sliding portion of the motor generator. In this case, even if the abnormal motor generator is electrically disconnected from the vehicle, the lock cannot be released, but the heat generation of the inverter or the like can be suppressed.

(Behavior control processing)
Next, vehicle behavior control processing executed by the HVECU 50 will be described with reference to FIGS. 2 and 3. In the flowchart of FIG. 2, “S” represents a step.

In S400 of FIG. 2, the HVECU 50 determines whether or not the brake pedal 100 is depressed.
When the brake pedal 100 is depressed (S400: Yes), the HVECU 50 calculates the target behavior of the vehicle during traveling with the operation amount of the brake pedal 100 (S402), and shifts the processing to S406.

  When the brake pedal 100 is not depressed (S400: No), the HVECU 50 calculates the target behavior of the vehicle during traveling with the operation amount of the accelerator pedal 102 (S404), and shifts the processing to S406.

  In S406, the HVECU 50 determines whether or not the difference between the deceleration acceleration corresponding to the target behavior calculated from the operation amounts of the brake pedal 100 and the accelerator pedal 102 and the actual deceleration acceleration detected by the G sensor 104 exceeds a predetermined range. Determine.

  When the difference between the deceleration acceleration corresponding to the target behavior and the actual deceleration acceleration does not exceed the predetermined range (S406: No), the HVECU 50 sets the friction brake, the engine, and the engine so that the target behavior calculated in S402 or S404 is obtained. The torque generated as a whole vehicle is distributed to the motor generator and the transmission (S408).

  Here, even if a large braking force is applied and a large deceleration acceleration occurs because the driver suddenly steps on the brake pedal 100 in order to avoid a collision with an obstacle in front of the vehicle, it is calculated from an operation amount with respect to the brake pedal 100. Since it is the deceleration acceleration according to the made target behavior, determination of S406 becomes "No".

  As shown in FIG. 3, when the deceleration acceleration detected by the G sensor 104 increases rapidly regardless of the driving operation of the driver, and the difference between the deceleration acceleration corresponding to the target behavior and the actual deceleration acceleration exceeds a predetermined range ( S406: Yes), the HVECU 50 detects the abnormality of the regenerative brake based on the abnormality determination result of the MGECU 30 for the motor generator (S410).

MGECU 30 determines whether or not the regenerative braking by the motor generator is abnormal based on the rotation speed of the motor generator or the electric power generated by the motor generator.
When a DC brushless motor used as a motor generator is locked due to a magnetic field abnormality of a stator or a foreign object caught in a sliding portion, a large braking force is generated in a motor generator that operates as a regenerative brake. As a result, as shown in FIG. 3, acceleration in the deceleration direction is applied to the vehicle.

  When the abnormality of the regenerative brake is detected, the HVECU 50 sets the target behavior so that normal friction brakes other than the motor generator, the engine, and the transmission are compensated for the torque reduced by the braking force generated by the abnormal regenerative brake. Based on the difference between the deceleration acceleration corresponding to the behavior and the actual deceleration acceleration, the torque generated in the entire vehicle is distributed (412).

  For example, in order to compensate for the reduced torque, the HVECU 50 instructs the ENGECU 20 to increase the intake air amount by controlling the throttle device in the case of a gasoline engine as in the present embodiment. If it is a diesel engine, it instructs the ENGECU 20 to increase the injection amount of the injector. Further, the HVECU 50 instructs the TMECU 40 to shift down the transmission.

  When the HVECU 50 detects an abnormality in the regenerative brake, until the motor generator is disconnected from the vehicle in S414, which will be described later, in S412, the driver operates the brake pedal 100, the accelerator pedal 102, and the steering operation (not shown) by the driver. Make the detection interval shorter than when the regenerative brake is normal.

  Thus, the HVECU 50 calculates the target behavior of the vehicle at a short time interval until the regenerative brake is released based on the detected driving operation of the driver so that the torque generated as a whole vehicle becomes the target behavior. Then, the behavior control process in which the torque generated in the entire vehicle is distributed and commanded to each ECU is executed at short time intervals.

  The detection interval of the driving operation by the driver can be realized by, for example, installing a plurality of channels for AD-converting the operation amounts of the brake pedal 100, the accelerator pedal 102, and a steering wheel (not shown) and sequentially acquiring detection signals from the respective channels.

  Further, when detecting the abnormality of the regenerative brake, the HVECU 50 distributes the torque generated in the entire vehicle so that the torque generated in the entire vehicle becomes the target behavior until the motor generator is disconnected from the vehicle in S414 described later. Thus, the control time and control execution cycle when commanding each ECU are made shorter than when the regenerative brake is normal. As a result, the HVECU 50 can calculate the torque generated in the entire vehicle at short time intervals and distribute and instruct each ECU so that the actual behavior becomes the target behavior.

  As a result, as shown in the upper part of FIG. 3, before the motor generator is electrically disconnected from the vehicle in the next S414, the actual behavior of the vehicle is quickly matched with the target behavior, and the acceleration detected by the G sensor is regeneratively braked. It is possible to quickly return to the value before the occurrence of abnormality.

  Then, the HVECU 50 instructs the MGECU 30 to electrically disconnect the motor generator from the vehicle (S414). Thereby, when the regenerative brake is abnormal due to the magnetic field abnormality of the stator, it is possible to stop the regenerative brake from generating a braking force.

The HVECU 50 may instruct the MGECU 30 to disconnect the motor generator after the acceleration detected by the G sensor returns to the value before the occurrence of the regenerative brake abnormality.
If a foreign substance is caught in the rotating sliding part of the motor generator and a braking force is generated, the regenerative brake can stop mechanically generating the braking force even if the motor generator is electrically disconnected from the vehicle. Although not possible, the heat generation of the inverter can be suppressed by electrically disconnecting the motor generator from the vehicle.

  In S414, if the abnormal regenerative brake is disconnected, the HVECU 50 has excessive torque to compensate for the braking force generated by the abnormal regenerative brake. Therefore, the regenerative brake does not operate and only the friction brake generates the braking force. The torque generated by the entire vehicle is distributed to the friction brake, engine, and transmission so as to behave.

  As a result, as shown in the upper part of FIG. 3, even if the abnormal regenerative brake is disconnected, the actual behavior of the vehicle remains in a state that matches the target behavior set based on the driving operation of the driver, and the acceleration of the vehicle Fluctuation can be suppressed.

  When the HVECU 50 detects the abnormality of the regenerative brake, it is desirable to notify the driver of the abnormality of the regenerative brake by a warning light or the like. Thereby, the driver can bring the vehicle into a dealer or the like. Further, when detecting an abnormality of the regenerative brake, the HVECU 50 may perform retreat travel control such as limiting the intake air amount after disconnecting the motor generator from the vehicle.

  On the other hand, even if an abnormality occurs in the regenerative brake and a large braking force is generated, the torque generated by the abnormality in the regenerative brake can be achieved only by realizing the torque allocated to the engine and transmission other than the regenerative brake. In the control of the comparative example that does not compensate for the decrease in the vehicle, the deceleration state of the vehicle is not resolved, so the driver depresses the accelerator pedal 102 and tries to cancel the deceleration state of the vehicle.

  If the abnormal regenerative brake is disconnected from the vehicle while the driver is depressing the accelerator pedal 102 to eliminate the deceleration state of the vehicle, the braking force that has generated the regenerative brake disappears as shown in the lower part of FIG. The vehicle accelerates rapidly. Then, the driver hurries and depresses the brake pedal to try to decelerate the vehicle.

  As described above, when the driver performs the accelerator operation and the brake operation due to the abnormality of the regenerative brake, the vehicle behavior at the time of traveling becomes unstable, and the driver cannot perform an appropriate driving operation.

  In the present embodiment described above, even if an abnormality occurs in the regenerative brake and a large braking force is generated, resulting in a difference between the target behavior and the actual behavior of the vehicle, the torque is controlled by controlling the friction brake, engine, and transmission. Compensation eliminates the difference between the target behavior and the actual behavior of the vehicle as a whole, so that the acceleration of the vehicle quickly returns to the value before the regenerative brake abnormality.

  As a result, although the driver feels uneasy because the vehicle decelerates even though the brake pedal 100 is not operated, the driver avoids stepping on the accelerator pedal 102 in order to cancel the deceleration of the vehicle and regenerating. The same driving operation as before the brake abnormality occurred can be continued. As a result, the acceleration of the vehicle can be quickly returned to the target acceleration, and a stable running state can be continued.

In the present embodiment, the behavior processing in the case where an abnormality occurs in the regenerative brake and the regenerative brake generates a large braking force regardless of the driving operation of the driver has been described.
On the other hand, when an abnormality occurs in the regenerative brake and the braking force of the regenerative brake is not generated, the HVECU 50 compensates for the braking force generated if the regenerative brake is normal before disconnecting the regenerative brake. The behavior control may be performed by either increasing the braking force of the friction brake, decreasing the injection amount of the injector, shifting up the transmission, or combining them.

[Other Embodiments]
In the above embodiment, a system with one motor generator has been described. On the other hand, the present invention may be applied to a system in which a plurality of motor generators are installed.

  Further, the present invention is not limited to a hybrid vehicle and can be applied to any vehicle such as an electric vehicle as long as the vehicle obtains a braking force by coordinating a friction brake and a regenerative brake according to a driver's brake operation. Good.

  As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

2: Vehicle control system, 10: BRK ECU, 20: ENGECU, 30: MGECU, 40: TMECU, 50: HVECU (vehicle control device)

Claims (8)

A vehicle control device (50) applied to a vehicle that obtains braking force using a friction brake and a regenerative brake,
Behavior setting means (S402, S404) for setting the target behavior of the vehicle;
An abnormality detection means (S406, S410) for detecting an abnormality of the regenerative brake;
Regenerative stop means (S414) for disconnecting the regenerative brake and stopping the operation of the regenerative brake when the abnormality detection means detects an abnormality of the regenerative brake;
When the abnormality detecting means detects an abnormality of the regenerative brake, the target based on the difference between the target behavior set by the behavior setting means and the actual behavior of the vehicle before the regenerative stop means disconnects the regenerative brake. Behavior control means (S412) for controlling the actual behavior to match the behavior;
A vehicle control device comprising:   2. The vehicle control device according to claim 1, wherein the behavior control unit controls the actual behavior so as to coincide with the target behavior when the regeneration stop unit disengages the regenerative brake. 3.   3. The vehicle control device according to claim 1, wherein the behavior control unit controls the actual behavior so as to coincide with the target behavior until the regenerative stop unit disconnects the regenerative brake. 4. . The behavior setting means sets the target behavior based on a driving operation by a driver,
The abnormality detecting means detects an abnormality of the regenerative brake when a difference between the target behavior and the actual behavior exceeds a predetermined range;
The vehicle control device according to any one of claims 1 to 3, wherein   When the abnormality detecting unit detects an abnormality of the regenerative brake, the behavior control unit sets a control time and a control execution cycle when controlling the actual behavior so as to coincide with the target behavior before detecting the abnormality of the regenerative brake. The vehicle control device according to any one of claims 1 to 4, wherein the vehicle control device is shorter. Comprising an operation detection means (S412) for detecting a driving operation by the driver;
The behavior setting means (S412) sets the target behavior based on the driving operation detected by the operation detection means,
When the abnormality detecting unit detects an abnormality of the regenerative brake, the operation detecting unit sets the detection interval of the driving operation before the detection of the abnormality of the regenerative brake until the regenerative stop unit disconnects the regenerative brake. shorten,
The vehicle control device according to any one of claims 1 to 5, wherein   The operation detection means detects the driving operation based on an output result obtained by performing AD conversion on the driving operation by the driver in a plurality of channels, thereby shortening the detection interval of the driving operation than before detecting the abnormality of the regenerative brake. The vehicle control device according to claim 6.   The vehicle control device according to any one of claims 1 to 7, wherein the abnormality detection unit detects abnormality of the regenerative brake by detecting lock of a motor generator that realizes the regenerative brake. .

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