JP5573662B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that controls a driving force and a braking force so as to change a vehicle stability factor in accordance with a target value.

  When turning a vehicle, the driving force and braking force generated in the vehicle are automatically controlled in conjunction with the steering operation by the driver, thereby stabilizing the steering characteristics or stability factor of the vehicle and improving the turning performance of the vehicle. Technology to improve has been developed. As an example, Patent Document 1 describes an invention related to a vehicle stabilization control system for the purpose of suppressing the effects of driver operation disturbances and road surface disturbances and stabilizing vehicle body posture and vehicle characteristics. The invention described in Patent Document 1 is configured to correct the axle torque in consideration of the estimated running resistance disturbance and the state quantity so that the stability factor follows the target value.

  Patent Document 2 discloses a transmission of a hybrid vehicle configured to prohibit engine start when it is determined that the vehicle is in a coasting state or a turning state even when an engine start request is made. An invention relating to a state switching control device is described. In Patent Document 2, in a hybrid vehicle, for example, there is a case where an engine is not intended to be started by a driver due to a decrease in the amount of power stored in the battery. It is disclosed that when the control for cranking the engine is executed, the balance of the torque distribution of the wheels is lost, and the steering characteristics and traveling safety of the vehicle may be deteriorated.

  Further, in Patent Document 3, when an abnormality occurs in which the braking force of each wheel or the steering angle of the steered wheel cannot be normally controlled, the engine braking force in the accelerator-off state is reduced as compared with the normal state. The invention relating to the vehicle running stability control device configured as described above is described. Patent Document 3 discloses that when the vehicle turns while the accelerator is off, the engine braking force is reduced by prohibiting the stop of fuel supply.

JP 2005-256636 A JP 2007-331599 A JP-A-2005-139951

  In the invention described in Patent Document 1, when the vehicle turns, the vehicle behavior follows the target value of the stability factor, that is, the vehicle turns with the target steering characteristic. In addition, the torque applied to the vehicle is corrected and controlled. Therefore, the steering characteristics of the vehicle can be improved and the turning performance can be improved. However, for example, in the case where a vehicle whose engine start / stop is automatically controlled, such as a hybrid vehicle equipped with an engine and a motor as a driving power source or a so-called eco-run vehicle having an idling stop function, The engine may be started or stopped during the execution of the control for improving the turning performance. As a result, there is a possibility that the drivability of the vehicle may be reduced due to torque fluctuations that occur when the engine is started or stopped.

  For example, when a hybrid vehicle is to be controlled, as shown in FIG. 3, if the engine is started at time t1 while the vehicle is running, the engine torque during that time until the engine is stopped at time t2. The output torque of the motor is reduced in order to compensate for the increase. Therefore, the total driving torque of the vehicle is maintained at a substantially constant target value. However, when the engine is stopped and started, vibrational torque fluctuations are inevitably generated, so that unavoidable torque fluctuations also occur in the total driving torque of the vehicle, and as a result, continuity of the total driving torque is interrupted. End up. This causes a decrease in the drivability of the vehicle, and as a result, the target steering characteristics may not be properly realized.

  The present invention has been made paying attention to the technical problem described above, and when the driving force or braking force is controlled so that the vehicle stability factor is changed to follow the target value, the engine is started and stopped. It is an object of the present invention to provide a vehicle control device that can appropriately improve the turning performance of a vehicle while avoiding a decrease in drivability due to the vehicle.

  In order to achieve the above object, the invention of claim 1 has at least an internal combustion engine as a driving force source, and corrects the driving force or braking force generated by the output of the driving force source during turning. In a vehicle control device that executes turning performance improvement control that changes a stability factor to follow a target value, when the turning performance improvement control is executed, the operation state of the internal combustion engine changes from stop to start or combustion A control device comprising a driving force correcting means for correcting the driving force or the braking force so as not to be switched from operation to stop.

  The invention according to claim 2 is the invention according to claim 1, wherein the driving force correcting means prevents the stopped internal combustion engine from being started when the turning performance improvement control is executed. A control device including means for limiting correction of driving force.

  Further, the invention of claim 3 is the internal combustion engine stop prohibiting means for prohibiting the internal combustion engine in a combustion operation state from being stopped when the turning performance improvement control is executed in the invention of claim 1 or 2. The control device further includes the control device.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the vehicle includes a hybrid vehicle having the internal combustion engine and an electric motor as drive power sources, and the drive power is the internal combustion engine. And the driving force generated by the output of the electric motor, and when the driving force correction means executes the turning performance improvement control, the output of the electric motor is prevented so that the stopped internal combustion engine is not started. It is a control device characterized by including means for correcting the driving force generated by.

  According to the first aspect of the present invention, when executing the turning performance improvement control for correcting the driving force or braking force of the vehicle during turning and improving the turning performance of the vehicle by bringing the stability factor close to the target value, The operating state of the engine will not be switched, that is, the internal combustion engine that has been in a stopped state will not be started, or the internal combustion engine that has been in a combustion operating state will not be stopped. The driving force or braking force of the vehicle is controlled. Therefore, when executing the turning performance improvement control, it is possible to avoid the occurrence of vibrational torque fluctuation due to the internal combustion engine being started or stopped. As a result, it is possible to prevent the drivability from being lowered due to the torque fluctuation of the internal combustion engine and to appropriately improve the turning performance of the vehicle.

  According to the second aspect of the present invention, when the turning performance improvement control is executed, when the internal combustion engine is stopped, the internal combustion engine is not started with the execution of the turning performance improvement control. In addition, the correction of the driving force or braking force of the vehicle is limited. For example, the turning performance improvement control is executed by suppressing the correction of the driving force due to the output of the internal combustion engine and correcting the braking force. Therefore, when the turning performance improvement control is executed, it is possible to reliably avoid the occurrence of vibrational torque fluctuation caused by starting the stopped internal combustion engine. As a result, the turning performance of the vehicle can be appropriately improved by the turning performance improvement control while reliably preventing the drivability from being reduced due to the torque fluctuation of the internal combustion engine.

  According to the third aspect of the present invention, when the turning performance improvement control is executed, if the internal combustion engine is operated, the stop of the internal combustion engine is prohibited. That is, the turning performance improvement control is executed so that the internal combustion engine is not stopped with the execution of the turning performance improvement control. Therefore, when the turning performance improvement control is executed, it is possible to reliably avoid the occurrence of vibrational torque fluctuations caused by stopping the internal combustion engine that is being operated for combustion. As a result, the turning performance of the vehicle can be appropriately improved by the turning performance improvement control while reliably preventing the drivability from being reduced due to the torque fluctuation of the internal combustion engine.

  According to the fourth aspect of the present invention, when the turning performance improvement control is executed on a hybrid vehicle equipped with an internal combustion engine and an electric motor, the turning performance improvement control is performed when the internal combustion engine is stopped. The driving force by the output of the electric motor is corrected so that the internal combustion engine is not started with the execution of. That is, the internal combustion engine is not operated for combustion, and the turning performance improvement control is executed by correcting the driving force of the vehicle by the output of only the electric motor. Therefore, when the turning performance improvement control is executed, it is possible to reliably avoid the occurrence of vibrational torque fluctuation caused by starting the stopped internal combustion engine. As a result, even in the hybrid vehicle, the turning performance of the vehicle can be appropriately improved by the turning performance improvement control while reliably preventing the drivability from being reduced due to the torque fluctuation of the internal combustion engine.

It is a flowchart for demonstrating an example of the control performed by the control apparatus of the vehicle which concerns on this invention. It is a schematic diagram showing an example of a configuration of a vehicle and a control system to be controlled in the present invention. It is a time chart for demonstrating the condition where drivability deteriorates by the fluctuation | variation of vehicle torque when control by a prior art is performed.

  Next, an embodiment of the present invention will be described with reference to the drawings. First, an example of the configuration and control system of a vehicle to be controlled in the present invention will be described with reference to FIG. The vehicle targeted by the present invention controls the driving force and braking force of the vehicle independently of driving operations such as accelerator operation and braking operation by the driver, that is, driving of the vehicle based on the driving operation by the driver. Apart from the control of the force and the braking force, the driving force and the braking force can be automatically controlled. As an example, the vehicle Ve shown in FIG. 2 has left and right front wheels 1 and 2 and left and right rear wheels 3 and 4, and these rear wheels 3 and 4 are driven by power output from the driving force source 5. It is configured as a rear wheel drive vehicle.

  As the driving force source 5, at least one internal combustion engine is mounted. In addition, for example, both the internal combustion engine and an electric motor can be mounted as the driving force source 5 as a hybrid vehicle. As an internal combustion engine (hereinafter referred to as an engine), for example, a gasoline engine, a diesel engine, or a natural gas engine can be used. In that case, various transmissions (not shown) such as a manual transmission and an automatic transmission are used on the output side of the engine, that is, the driving force source 5.

  The engine mounted as the driving force source 5 is provided with, for example, an electronically controlled throttle valve or an electronically controlled fuel injection device. Accordingly, the output of the driving force source 5 can be automatically controlled by electrically controlling the operation of the electronically controlled throttle valve or the electronically controlled fuel injection device.

  An electronic control unit (ECU) 6 for controlling the output state of the driving force source 5 to control the driving state of the rear wheels 3 and 4 is provided. That is, the electronic control device 6 is connected to the driving force source 5, and the output of the engine, that is, the driving force source 5 is controlled by the electronic control device 6, so that the rear wheels 3, 4, that is, the driving wheels 3, 4 The driving force of the vehicle Ve to be generated can be automatically controlled.

  That is, when an engine is mounted as the driving force source 5 as described above, the driving force is controlled by controlling the operation of the electronically controlled throttle valve or the electronically controlled fuel injection device of the engine by the electronic control device 6. It is possible to automatically control the driving force of the vehicle Ve generated by the drive wheels 3 and 4 by automatically controlling the output of the source 5. For example, the vehicle Ve can be configured as a so-called eco-run vehicle having an idling stop function for stopping the combustion operation of the engine when the vehicle is temporarily stopped due to a signal waiting or traffic jam.

  When a motor is mounted on the vehicle Ve as a driving power source of the vehicle Ve in addition to the engine as described above, a power storage device (not shown) such as a battery or a capacitor is connected to the motor via an inverter, for example. Is connected. Then, by electrically controlling the inverter connected to the electric motor with the electronic control unit 6, the output of the electric motor is automatically controlled, and the driving force of the vehicle Ve generated by the driving wheels 3 and 4 is automatically controlled. Is configured to be possible.

  In addition, each of the wheels 1, 2, 3, and 4 is equipped with brake devices 7, 8, 9, and 10, respectively. Each of the brake devices 7, 8, 9, 10 is connected to the electronic control device 6 via the brake actuator 11. Therefore, by electrically controlling the operating state of each brake device 7, 8, 9, 10 by the electronic control device 6, the braking force of the vehicle Ve generated by each wheel 1, 2, 3, 4 is automatically and individually controlled. The configuration can be controlled.

  On the other hand, the electronic control device 6 is configured to receive detection signals from various sensors of each part of the vehicle Ve and information signals from various in-vehicle devices. For example, an accelerator sensor 12 that detects an accelerator depression angle (or depression amount or accelerator opening), a brake sensor 13 that detects a brake depression angle (or depression amount or brake opening), and a steering angle of a steering wheel are detected. Steering angle sensor 14, wheel speed sensor 15 for detecting the rotational speed (wheel speed) of each drive wheel 1, 2, 3, 4, and lateral acceleration sensor 16 for detecting acceleration (ie, lateral acceleration) in the axle direction of vehicle Ve. Detection signals from the yaw rate sensor 17 that detects the yaw rate of the vehicle Ve and various sensors (not shown) that detect the longitudinal acceleration, roll angle, pitch angle, and the like of the vehicle Ve are input to the electronic control unit 6. It is configured as follows.

  With the configuration as described above, the vehicle Ve can be controlled by changing the stability factor (or steering characteristic). In particular, the vehicle Ve according to the present invention can improve the turning performance of the vehicle Ve by changing the stability factor during turning to match the turning trajectory intended by the driver with the actual turning trajectory. It is configured as follows. That is, the vehicle Ve according to the present invention controls the stability factor of the vehicle Ve so as to follow the target value by automatically controlling the torque applied to the drive wheels and changing the stability factor of the vehicle Ve during turning. The so-called “line trace control” or “turning performance improvement control” can be executed.

  As described above, by executing the “turning performance improvement control” as described above while the vehicle Ve is turning, the actual stability factor of the vehicle Ve that is turning is followed by the target stability factor. As a result, the turning performance of the vehicle Ve can be improved, and the vehicle Ve can be turned as intended or stably. On the other hand, when the engine is mounted as the driving force source 5 for generating the driving force of the vehicle Ve as in the vehicle Ve shown in FIG. When the engine is started or stopped, the drivability of the vehicle Ve decreases due to torque fluctuations that are inevitably generated when the engine is started or stopped, or the control effect of “turning performance improvement control” is reduced. It may become impossible to obtain properly.

  Therefore, in the control apparatus for the vehicle Ve according to the present invention, when the “turning performance improvement control” is executed during the turning of the vehicle Ve, the engine that has been stopped is not switched, that is, the engine has been stopped. Is configured so that the driving force or braking force of the vehicle Ve is corrected in the “turning performance improvement control” so that the engine that has been in a combustion operation is not stopped. Has been.

  FIG. 1 is a flowchart for explaining an example of the control, and the routine shown in this flowchart is repeatedly executed every predetermined short time. In FIG. 1, first, a control amount for executing “turning performance improvement control” by driving force (or braking force) is calculated (step S1). The control amount here is a control amount for performing control to correct the driving force or braking force of the vehicle Ve in order to make the stability factor of the vehicle Ve follow the target value in the “turning performance improvement control”. In other words, it is a correction amount for correcting the driving force or braking force of the vehicle Ve.

  Next, it is determined whether or not the engine is intermittent, that is, whether or not the engine is temporarily stopped (step S2). If an affirmative determination is made in step S2 because the engine is stopped, the process proceeds to step S3, and it is determined whether or not the engine is started by adding the control amount obtained in step S1 above. To be judged. That is, when executing the “turning performance improvement control”, the temporarily stopped engine is started by correcting the driving force or braking force of the vehicle Ve based on the control amount obtained in step S1 above. It is determined whether or not it is allowed.

  If it is estimated that the engine will start when the driving force or braking force of the vehicle Ve is corrected based on the control amount obtained in step S1, if the determination in step S3 is affirmative, step S4 is performed. The control amount is limited to a range where the engine is not started. That is, the correction is limited so that the engine is not started even if the driving force or braking force of the vehicle Ve is corrected based on the control amount.

  For example, it is necessary to increase the driving force of the vehicle Ve in order to make the stability factor of the vehicle Ve follow the target value, and when the engine output is required to increase the driving force, that is, the vehicle Ve is stopped. If it is determined that the engine needs to be started and output, correction of the driving force by the output of the engine is limited. Instead, the “turning performance improvement control” is executed so that the desired stability factor is obtained by correcting the braking force of the vehicle Ve, that is, the stability factor is as close as possible to the target value. Is done.

  Further, when the vehicle Ve is a hybrid vehicle in which an engine and an electric motor such as a motor or a motor / generator are mounted as the driving force source 5, the vehicle Ve is used in order to make the stability factor of the vehicle Ve follow the target value. If it is determined that the engine output is required to increase the driving force, that is, it is determined that the stopped engine needs to be started and output, The correction of the driving force by the engine output is limited. Instead, the "turning performance improvement control" is performed so that the desired stability factor is obtained by correcting the driving force due to the output of the motor, that is, the stability factor is as close as possible to the target value. Executed. In other words, when “turning performance improvement control” is executed for a hybrid vehicle, the driving force generated by the output of the electric motor is corrected so that the stopped engine is not started, "Improvement control" is executed.

  As described above, when the “turning performance improvement control” is executed for a hybrid vehicle equipped with an engine and an electric motor, when the engine is stopped, the “turning performance improvement control” is executed. Accordingly, the driving force by the output of the electric motor is corrected so that the engine is not started. That is, the engine is not combusted and the driving force of the vehicle Ve is corrected by the output of only the electric motor, whereby “turning performance improvement control” is executed. Therefore, when the “turning performance improvement control” is executed, it is possible to reliably avoid the occurrence of vibrational torque fluctuation caused by starting the stopped engine. As a result, even in a hybrid vehicle, the turning performance of the vehicle Ve can be appropriately improved by the “turning performance improvement control” while reliably preventing a decrease in drivability due to engine torque fluctuation.

  If the control amount is limited in step S4 so that the engine is not started even if the driving force or braking force of the vehicle Ve is corrected, it is limited to the required driving force based on the driving operation of the driver. The controlled amount is added (step S5). That is, the driving force of the vehicle Ve is controlled based on the required driving force that takes into account the limited control amount as described above. Thereafter, this routine is once terminated.

  On the other hand, if it is estimated that the engine will not start even if the driving force or braking force of the vehicle Ve is corrected based on the control amount obtained in step S1, the result in step S3 is negative. If it is determined automatically, the above-described step S4 is skipped, and the control of the above-described step S5 is executed in the same manner.

  On the other hand, after the control amount in the “turning performance improvement control” is obtained in step S1, the negative determination is made in step S2 because the engine is not intermittent, that is, the engine is in a combustion operation. In this case, the process proceeds to step S6, and it is determined whether or not “turning performance improvement control” is being executed. If “turning performance improvement control” is not being executed, and if a negative determination is made in step S6, this routine is terminated without executing the subsequent control.

  On the other hand, if “turning performance improvement control” is being executed, if the determination in step S6 is affirmative, the process proceeds to step S7, and an engine stop prohibition request command is output. That is, it is prohibited that the engine in the combustion state is stopped. Thereafter, the control in step S5 is executed in the same manner, and thereafter, this routine is temporarily terminated.

  As described above, when the “turning performance improvement control” is executed, if the engine is in a combustion operation, the engine is prohibited from being stopped. That is, the “turning performance improvement control” is executed so that the engine is not stopped with the execution of the “turning performance improvement control”. Therefore, when the “turning performance improvement control” is executed, it is possible to reliably avoid the occurrence of vibrational torque fluctuations caused by stopping the engine that is in the combustion operation. As a result, it is possible to appropriately improve the turning performance of the vehicle Ve while reliably preventing a decrease in drivability due to engine torque fluctuation during execution of the “turning performance improvement control”.

  As described above, according to the control device for the vehicle Ve according to the present invention, the driving force or the braking force of the vehicle Ve during turning is corrected, and the stability factor is brought close to the target value to improve the turning performance of the vehicle Ve. When executing the `` turning performance improvement control '', the engine operating state is not switched, that is, the engine that has been stopped is not started or is in the combustion operating state. The driving force or braking force of the vehicle Ve is controlled so that the engine is not stopped. Therefore, when executing the “turning performance improvement control”, it is possible to avoid the occurrence of vibrational torque fluctuation due to the engine being started or stopped. As a result, it is possible to prevent a decrease in drivability due to engine torque fluctuation during execution of the “turning performance improvement control” and to appropriately improve the turning performance of the vehicle Ve.

  Further, when the “turning performance improvement control” is executed, if the engine is stopped, the vehicle Ve is prevented from being started with the execution of the “turning performance improvement control”. Correction of driving force or braking force is limited. For example, the correction of the driving force by the output of the engine is suppressed, and the “braking performance improvement control” is executed by correcting the braking force instead. Therefore, when the “turning performance improvement control” is executed, it is possible to reliably avoid the occurrence of vibrational torque fluctuation caused by starting the stopped engine. As a result, the turning performance of the vehicle Ve can be appropriately improved by the “turning performance improvement control” while reliably preventing a decrease in drivability due to engine torque fluctuation.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The functional means for executing steps S2 to S7 corresponds to the “driving force correcting means” in the present invention, and in particular, steps S6 and S7. The functional means for executing this corresponds to the “internal combustion engine stop prohibiting means” in the present invention.

  In the specific example described above, as the vehicle Ve to be controlled according to the present invention, the rear wheel drive that transmits the power of the driving force source 5 to the left and right rear wheels 3 and 4 to generate the driving force of the vehicle Ve. Although the configuration of the vehicle has been described as an example, it may be a front wheel drive vehicle that transmits the power of the driving force source 5 to the left and right front wheels 1 and 2 to generate the driving force of the vehicle Ve. Alternatively, it may be a four-wheel drive vehicle in which the power of the driving force source 5 is distributed and transmitted to the front wheels 1 and 2 and the rear wheels 3 and 4 and the driving force of the vehicle Ve is generated by all these wheels.

  DESCRIPTION OF SYMBOLS 1,2 ... Front wheel, 3, 4 ... Rear wheel, 5 ... Driving force source, 6 ... Electronic control unit (ECU) 7, 8, 9, 10 ... Brake device, 11 ... Brake actuator, 14 ... Steering angle sensor, DESCRIPTION OF SYMBOLS 15 ... Wheel speed sensor, 16 ... Longitudinal acceleration sensor, 17 ... Lateral acceleration sensor, Ve ... Vehicle.

Claims (4)

Turning performance improvement that has at least an internal combustion engine as a driving force source and changes the stability factor to follow the target value by correcting the driving force or braking force generated by the output of the driving force source during turning. In a control device for a vehicle that executes control,
Driving force correction means for correcting the driving force or the braking force so that the operating state of the internal combustion engine is not switched from stop to start or from combustion operation to stop when the turning performance improvement control is executed; A control apparatus for a vehicle, comprising:   The driving force correcting means includes means for limiting the correction of the driving force so that the stopped internal combustion engine is not started when the turning performance improvement control is executed. Item 2. The vehicle control device according to Item 1.   The vehicle according to claim 1, further comprising an internal combustion engine stop prohibiting unit that prohibits the internal combustion engine in a combustion operation state from being stopped when the turning performance improvement control is executed. Control device. The vehicle includes a hybrid vehicle having the internal combustion engine and an electric motor as a driving force source,
The driving force includes a driving force generated by the output of the electric motor together with the internal combustion engine,
The driving force correcting means includes means for correcting the driving force generated by the output of the electric motor so that the stopped internal combustion engine is not started when the turning performance improvement control is executed. The vehicle control device according to claim 1, wherein the vehicle control device is a vehicle control device.

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