JP4752261B2 - Vehicle turning control device - Google Patents

Description

  The present invention relates to a turning control device for a vehicle that achieves stable turning.

There has been a case in which the vehicle is turned slowly by controlling the braking force and the engine torque so that the turning speed and turning radius of the vehicle do not exceed the limit of turning performance (see Patent Document 1).
In addition, for example, when controlling the vehicle behavior by decelerating the vehicle to a safe vehicle speed during turning, the driver requests acceleration when the amount of operation of the accelerator pedal tends to increase or exceeds a reference value. In some cases, it is determined that the vehicle has been controlled and the vehicle behavior control is terminated (see Patent Document 2).
Japanese Patent No. 2600876 JP 2002-127888 A

If a braking force is generated by automatic deceleration while the driver is stepping on the accelerator pedal, an energy loss of the braking / driving force is caused by the amount of interference between the driving force and the braking force. Therefore, in the conventional example described in Patent Document 1, it is conceivable to reduce the engine torque to zero when the braking force is generated by automatic deceleration. However, when the engine torque is reduced to zero, the accelerator pedal is depressed. It gives a driver a sense of stall. Conversely, as in the conventional example described in Patent Document 2, if the deceleration control is terminated with priority given to the driver's intention to accelerate, there is a risk that stable turning of the vehicle cannot be ensured.
Accordingly, the present invention has been made paying attention to the above problems, and provides a vehicle turning control device that can ensure a stable turning of the vehicle without giving the driver unnecessary sense of stall. It is an issue.

In order to solve the above problems, a turning control device for a vehicle according to the present invention calculates a target vehicle speed necessary for ensuring stable turning of the host vehicle, and calculates the target vehicle speed and the turning speed of the host vehicle. determining whether or not to decelerate the vehicle in response to, while the driver is judged that to decelerate the vehicle while performing the accelerator operation, as orbiting speed of the vehicle becomes the target vehicle speed The brake torque is generated and the drive torque acting on the drive wheels is reduced to the lower limit value. The higher the turning speed of the host vehicle, the higher the lower limit value of the drive torque is set. The lower limit value of the drive torque is set to a higher value as the value is higher, and the lower limit value of the drive torque is set to a higher value as the turning speed of the host vehicle is higher and the target vehicle speed is higher.
In addition, when the driving torque is decreased by a predetermined amount from the driving torque every predetermined time to reduce the driving torque to the lower limit value, and the driver request torque corresponding to the driver's accelerator operation is smaller than the driving torque decreased by the predetermined amount. The driver request torque is made the final drive torque.

  When the vehicle speed is higher than when it is low, the driving torque required to maintain the vehicle speed is larger. Accordingly, when the driving torque acting on the drive wheels is reduced to the lower limit value as in the vehicle turning control device according to the present invention, the lower limit value of the driving torque is set to a higher value as the turning speed of the host vehicle is higher. As a result, excessive torque reduction is prevented, and the driver who has performed the accelerator operation is not given a sense of unnecessary stall. On the contrary, by setting the lower limit value of the driving torque to a lower value as the turning speed of the host vehicle is lower, it is possible to eliminate excessive driving torque and to ensure stable turning traveling of the vehicle.

  On the other hand, even if the turning speed is the same, the driving torque that can ensure stable turning travel is greater when a small steering operation is performed than when a large steering operation is performed. Therefore, when the drive torque acting on the drive wheels is reduced to the lower limit value, the lower the drive torque lower limit value is set to a higher value as the target vehicle speed required to ensure stable turning of the host vehicle is higher, An excessive torque reduction is prevented, and the driver who has operated the accelerator is not given a sense of unnecessary stall. Conversely, by setting the lower limit value of the drive torque to a lower value as the target vehicle speed required to ensure stable turning of the host vehicle is reduced, excess drive torque can be eliminated and vehicle stability can be eliminated. Can be ensured.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of the present invention. An electromagnetic induction wheel speed sensor 1 for detecting the wheel speed Vwi (i = FL to RR) of each wheel, an optical / non-contact type steering angle sensor 2 for detecting the steering angle θ of the steering wheel, A yaw rate sensor 3 that detects the yaw rate φ _D and an accelerator sensor 4 that detects the accelerator opening Acc of the accelerator pedal are connected to the controller 5.

The controller 5 is composed of, for example, a microcomputer, and executes a turning traveling control process, which will be described later, based on detection signals from the respective sensors, and drives and controls the engine output control device 6 and the braking force control device 8. Automatic deceleration is performed according to the turning state.
Here, the engine output control device 6 is configured to control the engine output (the number of revolutions and the engine torque) by adjusting the throttle valve opening, the fuel injection amount, the ignition timing, and the like in the engine 7. .

Further, as shown in FIG. 2, the braking force control device 8 is interposed between the master cylinder 10 and the wheel cylinders 11FL to 11RR.
The master cylinder 10 is a tandem type that produces two systems of hydraulic pressure according to the driver's pedaling force. The master cylinder 10 transmits the primary side to the front left and rear right wheel cylinders 11FL and 11RR, and the secondary side transmits the right front wheel and A diagonal split system is used for transmission to the left rear wheel cylinders 11FR and 11RL.

Each of the wheel cylinders 11FL to 11RR is incorporated in a disc brake that presses a disc rotor with a brake pad to generate a braking force, or a drum brake that generates a braking force by pressing a brake shoe against the inner peripheral surface of the brake drum. Yes.
The braking force control device 8 uses a braking fluid pressure control circuit used for anti-skid control (ABS), traction control (TCS), stability control (VDC: Vehicle Dynamics Control), and the like. Regardless of the operation, the hydraulic pressure in each of the wheel cylinders 11FL to 11RR can be increased, held and reduced.

  The primary side has a normally open type first gate valve 12A capable of closing a flow path between the master cylinder 10 and the wheel cylinder 11FL (11RR), and a flow path between the first gate valve 12A and the wheel cylinder 11FL (11RR). A normally open type inlet valve 13FL (13RR) that can be closed, an accumulator 14 communicating between the wheel cylinder 11FL (11RR) and the inlet valve 13FL (13RR), and a flow path between the wheel cylinder 11FL (11RR) and the accumulator 14 are provided. A normally closed outlet valve 15FL (15RR) that can be opened and a flow path that communicates between the master cylinder 10 and the first gate valve 12A and between the accumulator 14 and the outlet valve 15FL (15RR) are opened. The normally closed type second gate valve 16A, the accumulator 14 and the outlet valve 15FL (15RR) are connected to the suction side, and the first gate valve 12A and the inlet valve 13FL (13RR) are connected to the discharge side. And a pump 17. A damper chamber 18 is disposed on the discharge side of the pump 17 to suppress pulsation of discharged brake fluid and weaken pedal vibration.

Similarly to the primary side, the secondary side also has a first gate valve 12B, an inlet valve 13FR (13RL), an accumulator 14, an outlet valve 15FR (15RL), a second gate valve 16B, a pump 17, A damper chamber 18.
The first gate valves 12A and 12B, the inlet valves 13FL to 13RR, the outlet valves 15FL to 15RR, and the second gate valves 16A and 16B are two-port, two-position switching, single solenoid, and spring offset type electromagnetic operations, respectively. The first gate valves 12A and 12B and the inlet valves 13FL to 13RR open the flow path at a non-excited normal position, and the outlet valves 15FL to 15RR and the second gate valves 16A and 16B are non-excited. The flow path is closed at the normal position.

The accumulator 14 is a spring-type accumulator in which a compression spring is opposed to a cylinder piston.
The pump 17 is a positive displacement pump such as a gear pump or a piston pump that can ensure a substantially constant discharge amount regardless of the load pressure.
With the above configuration, the primary side will be described as an example. When the first gate valve 12A, the inlet valve 13FL (13RR), the outlet valve 15FL (15RR), and the second gate valve 16A are all in the non-excited normal position. Then, the hydraulic pressure from the master cylinder 2 is transmitted as it is to the wheel cylinder 11FL (11RR) and becomes a normal brake.

  Even when the brake pedal is not operated, the first gate valve 12A is energized and closed while the inlet valve 13FL (13RR) and the outlet valve 15FL (15RR) are kept in the non-excited normal position. The second gate valve 16A is excited and opened, and the pump 17 is further driven to suck the hydraulic pressure of the master cylinder 2 through the second gate valve 16A and discharge the hydraulic pressure to the inlet valve 13FL (13RR). ) To the wheel cylinder 11FL (11RR) to increase the pressure.

  If the inlet valve 13FL (13RR) is excited and closed when the first gate valve 12A, the outlet valve 15FL (15RR), and the second gate valve 16A are in the non-excited normal position, the wheel cylinder 11FL (11RR) is closed. ) To the master cylinder 2 and the accumulator 14 are blocked, and the hydraulic pressure of the wheel cylinder 11FL (11RR) is maintained.

  Further, when the first gate valve 12A and the second gate valve 16A are in the non-excited normal position, the inlet valve 13FL (13RR) is excited and closed, and the outlet valve 15FL (15RR) is excited and opened. The hydraulic pressure in the wheel cylinder 11FL (11RR) flows into the accumulator 14 and is reduced. The hydraulic pressure flowing into the accumulator 14 is sucked by the pump 17 and returned to the master cylinder 2.

Also on the secondary side, the normal braking, pressure increasing, holding, and pressure reducing operations are the same as the operations on the primary side, and detailed description thereof will be omitted.
Therefore, the controller 5 controls each wheel by drivingly controlling the first gate valves 12A and 12B, the inlet valves 13FL to 13RR, the outlet valves 15FL to 15RR, the second gate valves 16A and 16B, and the pump 17. The fluid pressure in the cylinders 11FL to 11RR is increased / held / reduced.

In the present embodiment, a diagonal split method is used in which the brake system is divided into front left / rear right and front right / rear left, but the present invention is not limited thereto. The front / rear split method may be adopted.
Further, in the present embodiment, the spring-shaped accumulator 14 is adopted, but the present invention is not limited to this, and brake fluid extracted from each wheel cylinder 11FL to 11RR is temporarily stored to efficiently reduce pressure. Therefore, any type such as a weight type, a gas compression direct pressure type, a piston type, a metal bellows type, a diaphragm type, a bladder type, and an in-line type may be used.

  In the present embodiment, the first gate valves 12A and 12B and the inlet valves 13FL to 13RR open the flow path at the non-excited normal position, and the outlet valves 15FL to 15RR and the second gate valves 16A and 16B are non-excited. Although the flow path is closed at the normal excitation position, the present invention is not limited to this. In short, since it is only necessary to open and close each valve, the first gate valves 12A and 12B and the inlet valves 13FL to 13RR open the flow path at the excited offset position, and the outlet valves 15FL to 15RR and the second gate are opened. The valves 16A and 16B may close the flow path at the excited offset position.

Next, the turning traveling control process executed by the controller 5 will be described based on the flowchart of FIG.
The turning control process is executed as a timer interruption process at predetermined time intervals (for example, 10 msec). As shown in FIG. 3, first, in step S1, each wheel speed Vwi, steering angle θ, and yaw rate detection value φ _D Then, the accelerator opening Acc is read.
In the subsequent step S2, the turning speed V is calculated based on each wheel speed Vwi. In this embodiment, the turning speed V is calculated based on each wheel speed Vwi. However, the present invention is not limited to this. The longitudinal acceleration of the vehicle body is detected by an acceleration sensor, and the longitudinal acceleration is taken into account. Thus, the turning speed V may be calculated.
In the subsequent step S3, the yaw rate φ of the vehicle body is calculated according to the block diagram of FIG.

First, the yaw rate estimated value φ _E is calculated according to the steering angle θ and the turning speed V with reference to a control map as shown in FIG. The control map used for calculating the yaw rate estimated value phi _D, as shown in FIG. 5, the horizontal axis steering angle theta, the vertical axis is the yaw rate estimated value phi _D, yaw rate phi _D as the steering angle theta increases The rate of increase is set so that the rate of increase decreases as the turning speed V increases. Then, as shown in the following equation (1), the final yaw rate φ is calculated by selecting high of the absolute value of the yaw rate detection value φ _{D and} the absolute value of the yaw rate estimation value φ _E. Here, for performing select-high of the estimated value phi _E and the detected value phi _D, for example to the steering angle at low roads road surface friction coefficient mu theta is not too large when a slow spin mode in which yaw rate phi increases This is because the deceleration control can be intervened earlier.
φ = max [| φ _D |, | φ _E |] (1)

In the subsequent step S4, the target turning speed V ^* for the current turning state is calculated as shown in the following equation (2). Here, μ is a road surface friction coefficient, which is estimated based on a slip ratio and a brake operation amount (master cylinder pressure), estimated based on road surface image data and air temperature, or a road surface discrimination sensor (GVS: It is estimated based on the detection result of (Grand View Censor), and further acquired from the infrastructure. Yg _L is a limit lateral acceleration, and is set to a predetermined value (eg, 0.45 G) at which the vehicle can stably turn, but may be variable according to the slip ratio of each wheel.
V ^* = μ × Yg _L / | φ | (2)

In the subsequent step S5, the target deceleration Xg ^* is calculated as shown in the following equation (3). Here, ΔV is a deviation (V−V ^* ) between the turning speed V and the target turning speed V ^* , t is a predetermined time, and k is a coefficient.
Xg ^* = k × ΔV / t (3)
Here, the target deceleration Xg ^* is simply calculated based on the deviation ΔV between the turning speed V and the target turning speed V ^* . However, the present invention is not limited to this, and is expressed by the following equation (4). In addition, the target deceleration Xg ^* may be calculated by taking into account the change rate (change amount per unit time) dΔV of the deviation ΔV in the increasing direction. Here, k1 and k2 are coefficients. Further, the change rate dΔV may be a change amount for each calculation cycle, or may be an average change amount within a predetermined time.
Xg ^* = (k1 × ΔV + k2 × dΔV) / t (4)

In a succeeding step S6, it is determined whether or not the target deceleration Xg ^* is greater than zero. When this determination result is Xg ^* ≦ 0, it is determined that deceleration control, that is, automatic deceleration is unnecessary, and the process proceeds to step S15 described later. On the other hand, when the determination result is Xg ^* > 0, it is determined that deceleration control is necessary, and the process proceeds to step S7.
In step S7, the deceleration control flag Fc is set to “1”.
In step S8, the calculated increase the target braking force F ^* which is required to achieve the target deceleration Xg ^*. However, the target braking force F ^* is increased at a predetermined change speed so that the braking force increases to such a degree that a stable vehicle behavior can be maintained.

In the subsequent step S9, as shown in the following equation (5), the target engine torque T ^* is calculated by subtracting a predetermined amount Tdown from the target engine torque T ^* _(n-1) before one sampling. However, the initial value of T ^* _(n-1) is set to the driver request engine torque Tdriver corresponding to the driver's accelerator opening Acc.
T ^* = T ^* _(n-1) -Tdown (5)
In the subsequent step S10, the control map as shown in the flowchart is referred to, and the lower limit value T ^* _MIN of the target engine torque is calculated according to the turning speed V. Here, the control map is set such that the horizontal axis is the turning speed V, the vertical axis is the lower limit value T ^* _MIN of the target engine torque, and the higher the turning speed V, the lower the target engine torque lower limit value T ^* _MIN. ing.

In a succeeding step S11, it is determined whether or not the target engine torque T ^* is smaller than the lower limit value T ^* _MIN . When this determination result is T ^* <T ^* _MIN , it is determined that the target engine torque T ^* is too narrow, and the process proceeds to step S12.
In step S12, as shown in the following formula (6), the target engine torque T ^* is limited to the lower limit value T ^* _MIN , and then the process proceeds to step S13.
T ^* ← T ^* _MIN (6)
On the other hand, when the determination result in step S11 is T ^* ≧ T ^* _MIN , the process proceeds to step S13.

In step S13, as shown in the following equation (7), the target engine torque T ^*, the select low and the driver required engine torque Tdriver corresponding to the accelerator opening Acc by the driver of the final target engine torque T ^* calculate.
T ^* = min [T ^* , Tdriver] (7)
In the subsequent step S14, the target engine torque T ^* and the target braking force F ^* are output as control commands, so that the engine output control device 6 and the braking force control device 8 are driven and controlled, and then a predetermined main program is restored. .

On the other hand, in step S15 which moves from the step S6, it is determined whether or not the deceleration control flag Fc is set to “1”. When the determination result is Fc = 0, it is determined that the deceleration control, that is, the automatic deceleration has not been started or has already ended, and the process returns to the predetermined main program. On the other hand, when the determination result is Fc = 1, it is determined that the deceleration control is started, and the process proceeds to step S16.
In step S16, the target braking force F ^* is decreased by the amount increased in the process of step S8. However, the target braking force F ^* is reduced at a predetermined change speed so that the braking force is reduced to such an extent that a stable vehicle behavior can be maintained.

In the subsequent step S17, as shown in the following equation (8), the target engine torque T ^* is calculated by adding a predetermined amount Tup to the target engine torque T ^* _(n-1) before one sampling.
T ^* = T ^* _(n-1) + Tup (8)
In the subsequent step S18, it is determined whether or not the deceleration control is completed, that is, the increment of the target braking force F ^* is canceled in step S16, and the target engine torque T ^* is determined as the current driver request engine torque Tdriver by the processing in S17. It is determined whether or not it has returned to. Here, when the increase in the target braking force F ^* is released and the target engine torque T ^* is restored to Tdriver, it is determined that the deceleration control has been completed, and the process proceeds to step S19.

In step S19, the deceleration control flag Fc is reset to “0”, and then the process proceeds to step S14.
On the other hand, if the increase in the target braking force F ^* is not released or the target engine torque T ^* is not returned to Tdriver in step S18, it is determined that the deceleration control has not ended and the step is continued. The process proceeds to S14.

  From the above, the processing in steps S2 and S3 corresponds to the “turning state detection means”, the processing in steps S5 and S6 corresponds to “deceleration determination means”, the processing in steps S9, S11 to S14, S17, and S18 and the engine. The output control device 6 corresponds to “driving torque control means”, the processing in step S10 corresponds to “target torque setting means”, and the processing in step S4 corresponds to “target vehicle speed calculation means”.

Next, operations and effects of the first embodiment will be described.
Now assume that the vehicle is turning. At this time, when the target deceleration Xg ^* is equal to or less than 0 (determination in Step S6 is “No”), it is determined that deceleration control, that is, automatic deceleration is not necessary because stable turning traveling is maintained. Therefore, the engine output control device 6 is brought into a non-driving state so that the normal engine torque according to the driver's accelerator operation is obtained, and the braking force control device 8 is set so as to be a normal brake according to the driver's brake operation. To the non-driven state.

From this state, when the driver's steering operation amount increases or the driver's accelerator operation amount increases and the target deceleration Xg ^* becomes larger than 0 (determination in step S6 is “Yes”), the vehicle Since the turning state is approaching the limit of turning performance, it is determined that deceleration control, that is, automatic deceleration is required.
Therefore, in order to achieve the target deceleration Xg ^* , the braking force control device 8 is driven and controlled to increase the hydraulic pressure of each wheel cylinder 7i, and the engine output control device 6 is driven and controlled to reduce the engine torque. Thus, automatic deceleration is performed to achieve stable turning (steps S8, S9, and S14).

  At this time, if the driver is stepping on the accelerator pedal, the engine torque may be reduced to zero when the braking force is generated by automatic deceleration, but if the engine torque is reduced to zero, the accelerator pedal is It gives a driver a feeling of stall. Conversely, if deceleration control is terminated with priority given to the driver's intention to accelerate, there is a risk that stable turning of the vehicle cannot be ensured.

The engine torque required to maintain the vehicle speed is higher when the vehicle speed is higher than when the vehicle speed is low. Therefore, in reducing the engine torque to the lower limit value T ^* _MIN, it sets the lower limit value T ^* _MIN engine torque as turning velocity V of the vehicle is high to a high value (step S10). Thus, when the error Njintoruku decreases to the lower limit value T ^* _MIN, preventing excessive torque reduction, is not to give unnecessary stall feeling to the driver had done the accelerator operation. Conversely, by setting the lower limit value T ^* _MIN of the engine torque to a lower value as the turning speed V is lower, excessive engine torque can be eliminated and stable turning traveling of the vehicle can be ensured.

As described above, when the target deceleration Xg ^* is reduced to 0 or less and the vehicle can return to a stable turning state by the deceleration control by increasing the braking force and decreasing the engine torque (determination in Step S6 is “No”). The braking force increased by the deceleration control is gradually decreased, and the engine torque is gradually increased to the driver request engine torque Tdriver (steps S16 and S17).

When the braking force increased by the deceleration control is released and the engine torque returns to the driver request engine torque Tdriver ("Yes" in step S18), the braking force control device 8 and the engine output control are controlled. Both the device 6 and the device 6 are brought into a non-driven state, and the deceleration control is terminated.
In the first embodiment, the drive torque acting on the drive wheels is reduced by reducing the engine torque. However, the present invention is not limited to this, and the transmission torque in the transmission is controlled. Thus, the drive torque acting on the drive wheels may be reduced.

In the first embodiment, the lower limit value T ^* _MIN of the engine torque is changed continuously and continuously in accordance with the turning speed V in the process of step S10. However, the present invention is not limited to this. The lower limit value T ^* _MIN of the engine torque may be changed stepwise according to the turning speed V, and it may be only one step. Further, the lower limit value T ^* _MIN of the engine torque is linearly changed according to the turning speed V, but is not limited to this, and the lower limit value of the engine torque is curved according to the turning speed V. T ^* _MIN may be changed.

In the first embodiment, the target deceleration Xg ^* is calculated based on the deviation ΔV between the turning speed V and the target turning speed V ^* . When the target deceleration Xg ^* is greater than 0, the deceleration is performed. Although control, that is, automatic deceleration is performed, the present invention is not limited to this, and the deceleration control may be performed when the turning speed V becomes higher than the target turning speed V ^* . Further, not only the turning speed but also the turning radius and the target turning radius may be calculated, and automatic deceleration may be performed when the turning radius becomes smaller than the target turning radius. It is only necessary that the deceleration control can be performed so as not to exceed the limit of the turning performance capable of stably turning.

  Moreover, in said 1st Embodiment, although the hydric brake which used hydraulic pressure as the transmission medium is employ | adopted as a braking mechanism which applies a brake, it is not limited to this, A cable, a link, Alternatively, any other braking mechanism using air pressure may be employed. Furthermore, even if it is not a friction brake that generates a braking force by a frictional resistance, such as pressing the disc rotor with a brake pad or pressing a brake shoe against the inner peripheral surface of the brake drum, an electromagnetic that generates a braking force by a magnetic resistance. Any other braking mechanism such as a brake, an aerodynamic brake that generates a braking force by air resistance, and a regenerative brake that generates a braking force by power generation may be employed.

Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, the lower limit value T ^* _MIN of the engine torque is changed according to the target vehicle speed V ^* .
That is, in the turning control processing in the second embodiment, a control map to be referred to in the process of step S10 described above, except that it has changed in the control map of FIG. 6, the same process as in the first embodiment Execute.

That is, in step S10, with reference to the control map of FIG. 6, to calculate the lower limit value T ^* _MIN of the target engine torque according to the target vehicle speed V ^*. In the control map of FIG. 6 , the horizontal axis represents the target vehicle speed V ^* , the vertical axis represents the lower limit value T ^* _{MIN of the} target engine torque, and the lower limit value T ^* _MIN of the target engine torque increases as the target vehicle speed V ^* increases. Is set. However, since the target vehicle speed V ^* becomes the maximum in a substantially straight state, when the target vehicle speed V ^* exceeds the predetermined value, is set as the lower limit value T ^* _MIN of the target engine torque is maintained at a constant value Yes.
Here, the process of calculating the lower limit value T ^* _MIN of the target engine torque with reference to the control map of FIG. 6 corresponds to “target torque setting means”.

By the way, even if the turning speed is the same, the driving torque that can ensure a stable turning travel is larger when a small steering operation is performed than when a large steering operation is performed. Therefore, in reducing the engine torque to the lower limit value T ^* _MIN, sets the lower limit value T ^* _MIN of as the engine torque target vehicle speed V ^* is higher that is necessary to ensure that turning stably in the vehicle to a high value it is, when d Njintoruku decreases to the lower limit value T ^* _MIN, preventing excessive torque reduction, it is not possible to give an unnecessary stall feeling to the driver had done the accelerator operation. Conversely, excessive engine torque can be eliminated by setting the lower limit value T ^* _MIN of the drive torque to a lower value as the target vehicle speed V ^* required to ensure stable turning of the host vehicle is lower. And stable turning of the vehicle can be ensured.
Other functions and effects are the same as those of the first embodiment described above.
If the first and second embodiments are combined, the respective effects can be obtained together.

Next, a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the lower limit value T ^* _MIN of the engine torque is set to a value that can maintain the target vehicle speed V ^* .
That is, in the turning control processing in the third embodiment, a control map to be referred to in the process of step S10 described above, except that it has changed in the control map of FIG. 7, the same processing as in the second embodiment Execute.

That is, in step S10, with reference to the control map of FIG. 7, to calculate the lower limit value T ^* _MIN of the target engine torque according to the target vehicle speed V ^* and yaw rate phi. In the control map of FIG. 7, the horizontal axis in the three-dimensional coordinates is the target vehicle speed V ^* , the vertical axis is the yaw rate φ, and the height axis is the engine torque lower limit value T ^* _MIN . Since the relationship between the target vehicle speed V ^* and the yaw rate φ is an inversely proportional curve as shown by ● according to the above equation (2), the smaller the yaw rate φ and the higher the target vehicle speed V ^* along this line, As indicated by ○, the engine torque lower limit value T ^* _MIN is set to be large. Here, the lower limit value T ^* _MIN of the engine torque indicated by ○ is preliminarily traveled with a corner having a turning radius R determined from the turning speed V and the yaw rate φ as a value capable of maintaining the limit lateral acceleration Yg _L in advance. Find out from experiments. In addition, when the road surface friction coefficient μ is taken into consideration as in the above-described equation (2), the lower limit value T ^* _MIN may be multiplied by the road surface friction coefficient μ (μ <1).

Therefore, the lower limit value T ^* _MIN of the target engine torque calculated according to the control map of FIG. 7 is the engine torque that can maintain the target vehicle speed V ^* that can be stably turned, so that the driver This makes it possible to maintain stable turning without requiring accelerator control.
Here, the process of calculating the lower limit value T ^* _MIN of the target engine torque with reference to the control map of FIG. 7 corresponds to “target torque setting means”.
Other functions and effects are the same as those of the second embodiment described above.

It is a block diagram which shows schematic structure of this invention. It is a hydraulic circuit diagram of a braking force control device. It is a flowchart which shows the turning traveling control process of 1st Embodiment. It is a block diagram which shows the calculation procedure of a yaw rate. It is a control map used for calculation of a yaw rate estimated value. It is a control map referred in 2nd Embodiment. It is a control map referred in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel speed sensor 2 Steering angle sensor 3 Yaw rate sensor 4 Accelerator sensor 5 Controller 6 Engine output control apparatus 7 Braking force control apparatus 10 Master cylinder 11FL-11RR Wheel cylinder 12A, 12B 1st gate valve 13FL-13RR Inlet valve 14 Accumulator 15FL- 15RR Outlet valve 16A, 16B Second gate valve 17 Pump 18 Damper chamber

Claims (2)

A turning state detecting means for detecting a turning speed of the own vehicle as a turning state of the own vehicle, a target vehicle speed calculating means for calculating a target vehicle speed necessary for ensuring stable turning traveling of the own vehicle, and the turning state detecting means A deceleration determination unit that determines whether or not to decelerate the host vehicle according to the turning speed of the host vehicle detected in step S3 and the target vehicle speed calculated by the target vehicle speed calculation unit, and when the deceleration determination unit decelerates the host vehicle. and braking means for turning speed of the vehicle when it is determined that a braking force is generated so that the target vehicle speed, said deceleration judgment means in a state where the driver is performing an accelerator operation is determined that the decelerating the host vehicle during and has a drive torque control means for reducing the driving torque acting on the drive wheel to the lower limit value, and the target torque setting means for setting a lower limit value of the driving torque as the turning speed of the vehicle is high to a high value Equipped with a,
The drive torque control means reduces the drive torque by a predetermined amount every predetermined time to reduce the drive torque to a lower limit value and responds to the driver's accelerator operation rather than the drive torque reduced by the predetermined amount. A vehicle turning control device , wherein when the driver request torque is small, the driver request torque is made a final drive torque . A turning state detecting means for detecting a turning speed of the own vehicle as a turning state of the own vehicle, a target vehicle speed calculating means for calculating a target vehicle speed necessary for ensuring stable turning traveling of the own vehicle, and the turning state detecting means A deceleration determination unit that determines whether or not to decelerate the host vehicle according to the turning speed of the host vehicle detected in step S3 and the target vehicle speed calculated by the target vehicle speed calculation unit, and when the deceleration determination unit decelerates the host vehicle. and braking means for turning speed of the vehicle when it is determined that a braking force is generated so that the target vehicle speed, said deceleration judgment means in a state where the driver is performing an accelerator operation is determined that the decelerating the host vehicle during and has a drive torque control means for reducing the driving torque acting on the drive wheel to the lower limit value, the drive as the target vehicle speed is high rotation speed of the higher and the vehicle calculated by the target vehicle speed calculating means It includes a target torque setting means for setting a lower limit value of the torque to a higher value, and
The drive torque control means reduces the drive torque by a predetermined amount every predetermined time to reduce the drive torque to a lower limit value and responds to the driver's accelerator operation rather than the drive torque reduced by the predetermined amount. A vehicle turning control device , wherein when the driver request torque is small, the driver request torque is made a final drive torque .

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