JP5862516B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control apparatus for a vehicle that controls driving force and braking force of a vehicle during turning, thereby improving the turning performance of the vehicle and stabilizing vehicle behavior during turning.

  When turning the vehicle, the driving force and braking force generated by the driver in conjunction with the steering operation by the driver are automatically controlled to improve the turning performance of the vehicle, and the behavior and posture of the vehicle during turning Techniques related to stable turning control have been developed. As an example, Patent Document 1 describes an invention relating to a vehicle stabilization control system that controls a driving force so that a vehicle stability factor follows a target value. In the invention described in Patent Document 1, a physical quantity for generating a basic required driving force requested by a driver at a driving wheel of a vehicle is calculated during turning, and is applied to a front wheel and a rear wheel of the vehicle, respectively. A stability factor target value is calculated based on the detection result of the applied load and the estimation result of the virtual turning radius of the vehicle. The physical quantity corresponding to the basic required driving force is corrected so that the vehicle stability factor follows the target value, and the driving force corresponding to the corrected physical quantity is generated on the driving wheels. .

  Patent Document 2 also describes an invention related to a vehicle driving force control device that controls driving force so as to change the vehicle stability factor in accordance with a target value. The invention described in Patent Document 2 obtains a target value of the stability factor based on a request for increasing the driving force, and based on a difference between the target value of the stability factor and the actual value of the stability factor. The correction amount of the stability factor is obtained, and the driving force is increased so that the difference between the target value and the actual value of the stability factor is reduced.

  Patent Document 3 describes an invention relating to a vehicle motion control device for the purpose of ensuring the stability of a vehicle without giving a sense of incongruity to the driver when a lane change is performed during traveling. Yes. In the invention described in Patent Document 3, the steering wheel is turned or turned back (first steering) from the straight traveling state to one turning direction, and then continuously turned to the other turning direction. When the turning change amount (steering angular velocity) during the first steering exceeds a predetermined value when the steering wheel is turned or turned back (second steering), the steering characteristic during the second steering is more understeered. It is configured to be modified to the side characteristics.

JP 2005-256636 A JP2011-236810A JP 2011-68169 A

  As described above, in each invention described in Patent Document 1 and Patent Document 2, the driving force of the vehicle is controlled so that the stability factor of the vehicle becomes the target stability factor. That is, so-called turning performance improvement control is executed. For example, as shown in FIG. 5, when the steering is started at time t11 and the vehicle turns, when the steering angle becomes a predetermined value or more, or when a predetermined time elapses after the steering is started, the turnability Improvement control is started (time t12). Specifically, the required driving force for the vehicle is reduced, and the actual driving force of the vehicle is reduced accordingly. In the example of the turning performance improvement control shown in FIG. 5, in order to prevent the driver from feeling uncomfortable or shock due to the automatic control of the driving force separately from the driver's intention, the control amount of the driving force is set. On the other hand, a limit value tqgd is provided. Therefore, the actual driving force is constant after the time t13, with the control amount being limited by the limit value tqgd.

  By executing the turning performance improvement control in this way, the vehicle behavior during turning can be stabilized, and the turning performance of the vehicle can be improved. Further, by providing a limit value for the control amount of the driving force in the turning performance improvement control as described above, the driver may feel uncomfortable or shock due to a variation in the driving force (or braking force) that is not intended by the driver. Can be prevented.

  However, the steering angle is returned to the 0 degree position after being steered in one turning direction, for example, when turning on an S-curve, and continuously steered in the other turning direction. When a so-called steering turn-back operation is performed, the experience effect of improving the turning performance by the driving force is insufficient, which may cause the driver to feel uncomfortable.

  For example, in the example shown in FIG. 6, the steering in one turning direction (R direction in FIG. 6) is performed at time t21 to start the first turning, and then the steering in the first turning at time t23. Is turned back to 0 degrees, and after time t25 when the steering angle returns to 0 degrees, steering in the other turning direction (L direction in FIG. 6) is performed and the second turning is started. . That is, a so-called steering turning operation is performed.

  When the turning operation as described above is performed, the first turn is started by steering in the R direction at time t21, and thus the turning performance improvement control is started at time t22 immediately after that. Specifically, the driving force of the vehicle is reduced. Thereafter, when the steering angle starts to return toward 0 degrees at time t23, the driving force control in the turning performance improvement control is returned to the normal state at time t24 immediately after that. That is, the driving force of the vehicle that has been reduced by the predetermined control amount is returned to the normal state where the control amount is zero. Then, when the steering angle becomes 0 degree at time t25 in the middle of returning the driving force of the vehicle to the normal state, and subsequently the second turning is started by steering in the L direction, that is, the steering turning operation Is performed, the turning performance improvement control is started again at time t26 immediately after that. That is, the driving force of the vehicle is reduced again.

  In this case, the control amount tqdstp_2 of the driving force that is controlled during the second turning of the turning operation is controlled from the state in the middle of being returned to the normal state as described above. Is smaller than the control amount tqdstp_1 of the driving force. There is no particular problem as long as the control amount tqdstp_2 during the second turning is large enough to allow the driver to fully experience the control effect of the turning performance improvement control. However, when the control amount tqdstp_2 at the time of the second turn is small, the driver cannot feel the control effect by the turning performance improvement control, and as a result, the driver can perform the expected turning performance improvement control. There may be another sense of incongruity that the control effect cannot be obtained.

  As described above, when the turning improvement control for stabilizing the vehicle behavior during turning is performed, if the steering turning operation as described above is performed, a sufficient control amount of the driving force is secured. As a result, there is a possibility that the control effect by the turning performance improvement control cannot be obtained sufficiently.

  The present invention has been made by paying attention to the above technical problem, and appropriately improves the turning performance without giving a sense of incongruity or shock to the driver even when the vehicle is turning when the turning operation of the steering is performed. It is an object of the present invention to provide a vehicle control device capable of executing the above.

In order to achieve the above object, a first aspect of the present invention provides a vehicle control apparatus capable of executing a turning performance improvement control for improving a turning performance of a vehicle by controlling a driving force with a predetermined control amount during turning. The steering detection means for determining whether the steering operation by the driver is a turn-back operation continuously steered in one turning direction and then steered in the other turning direction ; the discomfort caused by the control amount is insufficient when performing improved control to set the lower limit value of the control amount so as not to give the driver the pre Symbol steering operation is in the turn-back operation If it is determined, a control device, characterized in that said control amount and a drive force control means that limits at the lower limit.

The invention according to claim 2 is the invention according to claim 1 , wherein the steering detection means includes means for detecting at least one of a steering angular velocity and a steering angular acceleration, and the driving force control means is the switching operation in the turning operation. The control apparatus includes a means for setting the lower limit value so that the control amount increases as the steering angular velocity increases, or the control amount increases as the steering angular acceleration increases.

According to a third aspect of the present invention, in the first or second aspect of the present invention, when the driving force is controlled by the control amount in executing the turning performance improvement control, the change amount of the driving force is large. It further comprises drive force limiting means for limiting the control amount with a limit value set so as not to give the driver a sense of discomfort resulting from the driving force control means, wherein the steering operation is the turnover operation. The control device includes means for ensuring the magnitude of the control amount by temporarily relaxing the restriction of the control amount by the driving force limiting means when judged.

Then, the invention of claim 4, in the invention of any one of claims 1 or et 3, the driving force control means, in the state in which the forward turning operation is terminated, comprising means for eliminating the setting of the lower limit value This is a control device characterized by that.

  According to the first aspect of the present invention, when the vehicle is turning, the turning performance improvement control for automatically controlling the driving force of the vehicle and stabilizing the vehicle behavior during the turning is executed. When the turning performance improvement control is executed, if the driver performs a steering turning operation, the control amount is set to a lower limit so that the control amount of the driving force is not temporarily insufficient. A value is provided to ensure a control amount of a predetermined size or more. Therefore, even when the steering turning operation is performed, the driving force can be controlled with an appropriate control amount. As a result, the turning performance improvement control can be appropriately executed without giving the driver a sense of incongruity or shock.

  The driving force automatically controlled in the turning performance improvement control of the present invention includes a positive driving force for driving the vehicle and a negative driving force for braking the vehicle, that is, a braking force. For example, when the driving force is changed by the control amount in the positive direction, the output of the driving force source of the vehicle is increased. Alternatively, when the braking force has already been generated, the braking force is reduced. On the other hand, when the driving force is changed by a negative control amount, the output of the driving force source of the vehicle is reduced. Alternatively, a braking force is applied to the vehicle. Alternatively, if a braking force has already been generated, the braking force is increased.

The lower limit is set to the control amount of the driving force when the steering crosscut operation by the driver as above SL has been performed, the control amount of the driving force when performing a turning improving control It is set in consideration so as not to give the driver a sense of incongruity due to lack. For this reason, even when the turning operation is performed during turning, it is possible to reliably avoid the driver from feeling uncomfortable or shocked and appropriately execute the turning performance improvement control.

According to the second aspect of the present invention, the lower limit for the control amount is set in order to avoid shortage of the control amount in the transient state of the turning operation according to the magnitude of the steering angular velocity or the steering angular acceleration when the turning operation is performed. The magnitude of the value is changed. That is, control is performed such that the control amount increases as the steering angular velocity increases, or the control amount increases as the steering angular acceleration increases. When a quick steering operation in which the steering angular velocity or the steering angular acceleration is increased, it can be estimated that the driver expects a greater control effect than when a gentle steering operation is performed. Therefore, as described above, the lower limit value that determines the magnitude of the control amount of the driving force in accordance with the steering angular velocity or the steering angular acceleration at the time of the turning operation is set to reflect the driver's intention. Therefore, it is possible to execute appropriate turning performance improvement control.

According to the invention of claim 3 , when the turning performance improvement control is executed, the control amount (or change amount) of the driving force controlled at that time is caused by a large change in the driving force. The limit is set so as not to give the driver a sense of incongruity. Therefore, it is possible to prevent or suppress the driver from feeling uncomfortable or shocked by the change in the driving force of the vehicle during the turning performance improvement control. When the steering force is turned back when the control amount of the driving force is limited as described above, the limitation on the driving force is temporarily relaxed, so that the predetermined driving force control is performed. A control amount equal to or larger than the size of is secured. Therefore, it is possible to avoid a shortage of control amount of the transient driving force when the turning operation is performed, and it is possible to appropriately execute the turning performance improvement control as in the first aspect of the invention.

According to the fourth aspect of the present invention, the setting of the lower limit value for the control amount of the driving force is canceled in the state where the steering turning operation is finished. That is, when the turn-back operation is completed, the driving force control state in which the lower limit value is set for the control amount is returned to the normal driving force control state in which the lower limit value is not set. Therefore, it is possible to avoid a situation in which the control amount of the driving force becomes excessive when the turn-back operation is finished, and the driver feels uncomfortable, and as a result, the turning performance improvement control can be appropriately executed. it can.

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 flowchart for demonstrating an example of the turning property improvement control by the control apparatus of this invention. 7 is a time chart for explaining the behavior of the driving force of the vehicle when a steering turning operation is performed when the turning performance improvement control is executed. 3 is a time chart for explaining the behavior of the driving force of the vehicle when the turning performance improvement control of the present invention shown in FIG. 2 is executed. It is a time chart for demonstrating the example of the conventional turning property improvement control. It is a time chart for demonstrating the example of the conventional turning property improvement control.

  Next, an embodiment of the present invention will be described with reference to the drawings. First, 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. The vehicle Ve shown in FIG. 1 has left and right front wheels 1 and 2 and left and right rear wheels 3 and 4. In the example shown in FIG. 1, the vehicle Ve is configured as a rear-wheel drive vehicle that drives the rear wheels 3 and 4 by the power output from the driving force source 5.

  As the driving force source 5, for example, at least one of an internal combustion engine and an electric motor can be used. Alternatively, both the internal combustion engine and the electric motor can be mounted as the driving force source 5 as a hybrid vehicle. When an internal combustion engine such as a gasoline engine, a diesel engine, or a natural gas engine is mounted on the vehicle Ve as the driving force source 5, various transmissions such as a manual transmission and an automatic transmission are provided on the output side of the driving force source 5 ( (Not shown) is used. When an electric motor is mounted on the vehicle Ve as the driving force source 5, a power storage device (not shown) such as a battery or a capacitor is connected to the electric motor via an inverter, for example.

  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 unit 6 is connected to the driving force source 5 and the electronic control unit 6 controls the output of the driving force source 5 to generate the rear wheels 3 and 4, that is, the driving wheels 3 and 4. The driving force of the vehicle Ve can be automatically controlled.

  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, the braking force of the vehicle Ve generated by each wheel 1, 2, 3, 4 by controlling the brake actuator 11 by the electronic control device 6 and controlling the operation state of each brake device 7, 8, 9, 10 is achieved. It is the structure which can be automatically controlled individually.

  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 respectively, acceleration in the longitudinal direction (vertical direction in FIG. 1) of vehicle Ve (ie, longitudinal acceleration) ), A lateral acceleration sensor 17 that detects acceleration (ie, lateral acceleration) in the direction of the axle of the vehicle Ve (ie, lateral acceleration in FIG. 1), a yaw rate sensor 18 that detects the yaw rate of the vehicle Ve, or a drive. A detection signal from a torque sensor (not shown) for detecting the output torque of the force source 5 is electronically controlled. It is configured to be input to the device 6.

  With the configuration as described above, the vehicle Ve can control the steering characteristics and the stability factor. In particular, the vehicle Ve in the present invention is configured to improve the steering characteristics during turning while improving the turning performance of the vehicle Ve. For example, the vehicle speed and the friction coefficient of the road surface are estimated from the wheel speeds of the respective wheels 1, 2, 3, and 4 detected by the wheel speed sensor 15, the vehicle speed, the road surface friction coefficient, the steering angle detected by the steering angle sensor 14, and the like. Based on this, it is possible to set a target steering characteristic that is a target of the vehicle Ve, and to control the actual steering characteristic of the vehicle Ve to follow the target steering characteristic.

  Specifically, the actual steering characteristic of the vehicle Ve is changed to the target steering characteristic by controlling the yaw rate of the vehicle Ve by changing the driving force and the braking force of the vehicle Ve, that is, performing so-called turning improvement control. You can get closer. When controlling the yaw rate of the vehicle Ve, the target yaw rate of the vehicle Ve at that time is obtained based on information such as the vehicle speed, the steering angle, and the wheel base. Then, by performing the above-described turning performance improvement control, the yaw rate of the vehicle Ve can be controlled so that the actual yaw rate of the vehicle Ve approaches the target yaw rate. For example, by increasing or decreasing the correction torque with respect to the driving torque applied to the driving wheels 3, 4 or the braking torque applied to the wheels 1, 2, 3, 4, the vehicle Ve The yaw rate can be controlled.

  As described above, a control technique for setting the target yaw rate and causing the actual yaw rate of the vehicle Ve to follow the target yaw rate is described in, for example, Japanese Patent Laid-Open No. 5-278488. Japanese Patent Application Laid-Open No. 2011-218953 describes a control technique for controlling the driving force of the driving wheels so that the steering characteristic of the vehicle follows the target steering characteristic. Alternatively, as described above, Japanese Patent Application Laid-Open No. 2005-256636 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2011-236810 (Patent Document 2) describe the driving wheel so that the vehicle stability factor follows the target value. A control technique for controlling the driving force is described. As described above, the basic control contents of the turning performance improvement control that stabilizes the behavior and posture of the vehicle during turning by automatically controlling the driving force of the vehicle are well known by each of the above-mentioned patent documents. Here, a more specific description is omitted.

  As described above, in the conventional turning performance improvement control, when a so-called steering turning operation is performed in which steering is performed in one turning direction and then continuously steered in the other turning direction, There is a possibility that the control effect expected by the driver cannot be obtained due to insufficient control amount of the driving force control in the turning performance improvement control. Therefore, in the vehicle control device according to the present invention, when the turning performance improvement control is executed, an appropriate control amount of the driving force control is ensured even when the driver turns the steering wheel. It is configured to be able to.

  FIG. 2 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. 2, first, the execution state of the turning performance improvement control is determined (step S1). Specifically, it is determined whether or not the execution flag tqcntex for turning performance improvement control is set to “1”. The execution flag tqcntex is a flag that is set to “1” when the turning performance improvement control is executed, and is set to “0” when the turning performance improvement control is finished. The execution flag tqcntex is set to “0” at the beginning of this control.

  If the execution flag tqcntex is set to “0” and a negative determination is made in step S1, this routine is temporarily terminated without executing the subsequent control.

  On the other hand, if the execution flag tqcntex is set to “1” and the determination in step S1 is affirmative, the process proceeds to step S2. Then, it is determined whether or not a steering wheel turning operation has been performed by the driver. Specifically, it is determined whether or not the determination flag stacount for the switching operation is set to “1”. This determination flag stacount is a flag that is set to “1” when a steering turning operation is performed, and is set to “0” in other cases.

  In the present invention, for example, when the vehicle Ve travels on an S-curve, the steering operation is steered toward the other turning direction after being steered toward one turning direction, in other words, the steering. The steering operation in which the angle is reversed after crossing 0 degree is defined as a “turning operation” of the steering. The execution of the switching operation can be determined based on a value such as a steering angle, a steering angular velocity, a steering angular acceleration, or a change tendency.

  When the determination flag stacount of the switchback operation is set to “0”, that is, when the driver does not perform the steering switchback operation, and the determination is negative in this step S2, the following control is performed. This routine is terminated once without executing.

  On the other hand, when the determination flag stacount for the turning operation is set to “1”, that is, when the steering turning operation is performed by the driver, a positive determination is made in step S2, step S3 is performed. Proceed to Then, it is determined whether or not the deviation tqdstp between the driving force control amount tqrqorg required during the turning and the current driving force control amount tqrqcur is smaller than the threshold value x1.

  The driving force control amount tqrqorg and the driving force control amount tqrqcur are the driving force output based on the driver's accelerator operation in a state where the turning performance improvement control is not executed, as shown in the time chart of FIG. Further, it can be expressed as a difference from the actual driving force of the vehicle Ve (or the required driving force based on the turning performance improvement control) due to the execution of the turning performance improvement control.

  As shown in FIG. 3, when the turning operation is performed during turning, the driving force of the vehicle Ve is controlled by the driving force control amount tqrqorg by the turning improvement control with respect to the initial steering in the R direction. Is done. That is, the driving force of the vehicle Ve is reduced by the driving force control amount tqrqorg from the driving force output by the driver's accelerator operation. Then, when the turning operation is performed, the steering angle is returned to the direction of 0 degrees from the state where the steering is initially performed in the R direction. At the same time, the vehicle is steered in the L direction, which is the turning direction opposite to the R direction. In this case, since the steering angle is once returned to 0 degree during the turning operation, the actual driving force of the vehicle Ve controlled by the driving force control amount tqrqorg by the turning ability improvement control is once improved. It returns to the normal control state where control is not executed. However, since the steering angle passes through the state of 0 degree and is continuously steered in the L direction, the actual driving force of the vehicle Ve is again controlled by the driving force control amount tqrqorg by the turning performance improvement control. That is, the actual driving force of the vehicle Ve is reduced toward the driving force level that is reduced by the driving force control amount tqrqorg from the driving force generated by the driver's accelerator operation.

  At this time, since the actual driving force of the vehicle Ve has an inevitable response delay, when the actual driving force is reduced in response to the steering in the L direction at the time of the turning operation as described above, the actual driving force is Then, the state is lowered again from the state in the middle of returning to the normal state, that is, the state controlled by the current driving force control amount tqrqcur. Therefore, the deviation tqdstp between the driving force control amount tqrqorg and the driving force control amount tqrqcur is the driving force that actually changes in this case.

  If the change amount of the actual driving force, that is, the deviation tqdstp is sufficiently large, it is possible to appropriately obtain the control effect by the turning performance improvement control even when the above switching operation is performed. That is, the driver can appropriately experience the control effect of the turning performance improvement control. However, when the deviation tqdstp is small, the control effect by the turning performance improvement control is also small. Therefore, in step S3, a deviation tqdstp between the driving force control amount tqrqorg and the driving force control amount tqrqcur is obtained, and it is determined whether or not the deviation tqdstp is smaller than the threshold value x1.

  Here, the threshold value x1 is a value set as a lower limit value of the driving force control amount necessary for the driver to experience an appropriate control effect by the turning performance improvement control. The value can be set in advance by, for example, running experiments or simulations. Further, it is possible to set by applying the Weber's law concept that “the discrimination threshold (ΔX) of the stimulus changes in proportion to the intensity of the original stimulus (X) (ΔX / X = const)”. Specifically, if the absolute driving force when the turning performance improvement control is executed, that is, the driving force by the accelerator operation of the driver is considered as “X” in the above-mentioned Weber's law, the “const” portion is Thus, “ΔX”, that is, the threshold value x1 can be determined by specifying by experiment or simulation. Or, for example, if the driver senses a change in vehicle behavior due to a change in driving force during the turning performance improvement control, such as a yaw rate generated in the vehicle Ve, the “X” in the above Weber's law is The threshold value x1 can be determined by calculating the amount of change in driving force that can generate a yaw rate of “ΔX” as the yaw rate of the vehicle.

  Therefore, if the deviation tqdstp between the driving force control amount tqrqorg and the driving force control amount tqrqcur is greater than or equal to the threshold value x1, if the determination is negative in step S3 in the flowchart of FIG. 2, the subsequent control is executed. Without stopping, this routine is temporarily terminated. That is, if the deviation tqdstp is equal to or greater than the threshold value x1, it is considered that the driver can appropriately experience the control effect of the turning performance improvement control, and therefore it is determined that it is not particularly necessary to execute other controls.

On the other hand, when the deviation tqdstp between the driving force control amount tqrqorg and the driving force control amount tqrqcur is smaller than the threshold value x1, if the determination in step S3 is affirmative, the process proceeds to step S4. In step S4, x1 is set as the temporary driving force control amount tqrqt. The actual driving force control amount tqrq is obtained from the current driving force control amount tqrqcur and the temporary driving force control amount tqrqt. That is, the actual driving force control amount tqrq is
tqrq = tqrqcur + tqrqt = tqrqcur + x1
It is calculated by the following formula. Then, the driving force of the vehicle Ve is controlled by the driving force control amount tqrq, and measurement by the temporary driving force control counter ctqtmp is started.

  When the driving force control by the driving force control amount tqrq is started in step S4, it is determined whether or not the temporary driving force control counter ctqtmp exceeds the threshold value x2 (step S5). As described above, the control of the driving force by the driving force control amount tqrq obtained by adding the temporary driving force control amount tqrqt to the current driving force control amount tqrqcur, that is, the threshold value x1, is the transient driving force when the switching operation is performed. This is a control for avoiding that the control amount is insufficient. That is, as shown in the time chart of FIG. 3 described above, in the steady state where the driving force control amount tqrqorg can be secured, the expected control effect by the turning performance improvement control can be obtained. However, in a transient state where the control amount of the driving force becomes the driving force control amount tqrqcur, when the deviation tqdstp between the driving force control amount tqrqcur and the driving force control amount tqrqorg is smaller than the threshold x1, the turning performance improvement control is performed. The expected control effect cannot be obtained. Therefore, in step S4, as shown in the time chart of FIG. 4, the driving force is controlled by the driving force control amount tqrq obtained by adding the threshold x1 to the driving force control amount tqrqcur.

  However, as described above, the control of the driving force by the driving force control amount tqrq obtained by adding the threshold value x1 to the driving force control amount tqrqcur is to ensure a transient control effect when the turning operation is performed. It is. For this reason, the control amount becomes excessive in the state where the switching operation is finished, and the driver may feel uncomfortable. Therefore, in this step S5, as shown in the time chart of FIG. 4, a threshold value x2 is provided for the temporary driving force control counter ctqtmp, and transient driving is performed by the driving force control amount tqrq to which the threshold value x1 is added. The force control is returned to the state in which the driving force is controlled by the driving force control amount tqrqorg after a predetermined time has elapsed.

  Therefore, if the provisional driving force control counter ctqtmp has not yet exceeded the threshold value x2, and if a negative determination is made in step S5, the control in step S5 is executed again. That is, the control in step S5 is repeatedly executed until the temporary driving force control counter ctqtmp exceeds the threshold value x2.

  If the provisional driving force control counter ctqtmp exceeds the threshold value x2 and a positive determination is made in step S5, the process proceeds to step S6. Then, 0 is set as the temporary driving force control amount tqrqt. Further, the driving force control amount tqrqorg is set as the actual driving force control amount tqrq. Then, the temporary driving force control counter ctqtmp is reset to 0. Thereafter, this routine is once terminated.

  It should be noted that the threshold value x1 in the above control example can be set as a variable value corresponding to the driver's steering operation state, driving conditions, and the like. For example, when the driver performs a quick steering operation, the driver is expected to expect a large transient change due to the control effect of the turning performance improvement control. Therefore, when the driver performs a quick steering operation, the threshold value x1 is set to a larger value. Specifically, the steering angular velocity of the steering operation by the driver is detected, and the threshold value x1 is set to a larger value as the steering angular velocity is larger. Alternatively, the steering angular acceleration of the steering operation by the driver is detected, and the threshold value x1 is set to a larger value as the steering angular acceleration is larger. In this way, by setting the threshold value x1 according to the driver's quick steering operation, the control effect by the turning performance improvement control that the driver expects can be appropriately obtained.

  In addition, when the turning performance improvement control as described above is executed, by limiting the control amount when controlling the driving force, the driver feels uncomfortable or shocked due to the changing driving force. Can be suppressed. When the driving force of the vehicle Ve is controlled in the turning performance improvement control, the control effect by the turning performance improvement control becomes higher as the control amount of the driving force is larger. On the other hand, when the control amount of the driving force increases, the driving force change not related to the driver's accelerator operation increases, which may cause the driver to feel uncomfortable or shocked. Therefore, by setting a control amount that is as large as possible as the upper limit of the control amount when controlling the driving force within a range that does not give the driver a sense of discomfort or shock, it gives the driver a sense of discomfort or shock. Therefore, it is possible to appropriately execute the turning performance improvement control so as to obtain as high a control effect as possible.

  In the present invention, when the control amount of the driving force is limited as described above, the control amount is temporarily relaxed when the turning operation is performed. That is, as shown in the time chart of FIG. 4, when the limit value tqgd for preventing a sense of incongruity or a shock is provided for the control amount of the driving force, the driving force control amount in the specific example described above. Similar to the case where the deviation tqdstp between tqrqorg and the driving force control amount tqrqcur is smaller than the threshold value x1, the restriction on the driving force control amount by the limit value tqgd is relaxed for the period indicated by the threshold value x2. For this reason, even when the control amount of the driving force is limited as described above, it is possible to ensure a control amount equal to or greater than the threshold value x1 when controlling the driving force. Therefore, it is possible to avoid a shortage of the control amount of the transient driving force when the turning operation is performed, and it is possible to appropriately execute the turning performance improvement control as in the specific example described above.

  As described above, according to the control device for the vehicle Ve according to the present invention, when the vehicle Ve turns, the drive performance of the vehicle Ve is automatically controlled to stabilize the vehicle behavior during the turn. Is executed. And when the turning improvement control is executed, if the driver turns the steering wheel, the lower limit of the control amount is set so that the control amount of the driving force is not insufficient. A threshold value x1 is set as the value. That is, a control amount equal to or greater than the threshold x1 is ensured. Therefore, even when the steering turning operation is performed, the driving force control in the turning performance improvement control can be executed with an appropriate control amount. As a result, the turning performance improvement control according to the present invention can be appropriately executed without giving a sense of incongruity or shock to the driver even when the vehicle is turning with a steering turning operation.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The functional means for executing step S2 corresponds to the “steering detection means” in the present invention. The functional means for executing steps S3 to S5 corresponds to the “driving force control means” in the present invention.

  In the specific example described above, as the vehicle Ve to be controlled in the present invention, a rear wheel drive vehicle 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. However, 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.

  When the vehicle Ve is a four-wheel drive vehicle, instead of increasing / decreasing the driving force for turning performance improvement control as in the above-described specific example, the power of the driving force source 5 is changed to the front wheels 1, 2 and the rear wheels 3, 4 may be changed as appropriate. Also in this case, the degree of freedom of the driving force control in the turning performance improvement control is increased, and the turning performance improvement control can be executed more appropriately.

  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, 15 ... Wheel speed sensor, 16 ... longitudinal acceleration sensor, 17 ... lateral acceleration sensor, 18 ... yaw rate sensor, Ve ... vehicle.

Claims (4)

In a vehicle control apparatus capable of executing a turning performance improvement control for improving a turning performance of a vehicle by controlling a driving force with a predetermined control amount during turning traveling,
Steering detection means for determining whether the steering operation by the driver is a turn-back operation continuously steered in the other turning direction after being steered in one turning direction;
The discomfort of the control amount is due to insufficient when performing turning improving control sets the lower limit value of the control amount so as not to give the driver, before Symbol steering operation the crosscut operation If it is determined that the control device for a vehicle, characterized in that the control amount and a drive force control means that limits at the lower limit. The steering detection means includes means for detecting at least one of a steering angular velocity and a steering angular acceleration,
The driving force control means sets the lower limit value so that the control amount increases as the steering angular velocity in the turning operation increases, or the control amount increases as the steering angular acceleration increases. The vehicle control device according to claim 1, comprising: A limit value set so as not to give the driver an uncomfortable feeling due to a large amount of change in the driving force when the driving force is controlled by the control amount in executing the turning performance improvement control. And further comprising a driving force limiting means for limiting the control amount.
When it is determined that the steering operation is the turning operation, the driving force control means temporarily relaxes the restriction of the control amount by the driving force restriction means, thereby reducing the magnitude of the control amount. control apparatus for a vehicle according to claim 1 or 2, characterized in that it comprises a means for securing. The driving force control means, in the state in which the forward turning operation is terminated, the control of the vehicle according to any one of claims 1 or et 3, characterized in that it comprises a means for eliminating the setting of the lower limit value apparatus.

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