JP4311320B2 - Roll control device for vehicle - Google Patents

Description

The present invention actively controls the rolling state of the vehicle, to a roll control system for a vehicle.

Conventionally, roll suppression control devices such as so-called active suspensions (hereinafter abbreviated as active suspensions) and active stabilizers (hereinafter abbreviated as active stabilizers) that actively operate vehicle suspensions are widely known. Some have been put into practical use (for example, see Patent Document 1 below).
Among them, the active suspension actively controls the suspension stroke of the vehicle according to the running state of the vehicle and the road surface state, and the active stabilizer actively twists the stabilizer according to the running state of the vehicle. The roll angle is suppressed.

  6A and 6B are schematic diagrams showing the system configuration of the active stabilizer, FIG. 7 is a diagram showing its characteristics, and FIGS. 8A and 8B are diagrams showing its operation. In FIG. 6A, reference numeral 101 denotes a stabilizer body, and this stabilizer body 101 is interposed between left and right suspensions (not shown). One end of the stabilizer body 101 is connected to the suspension via a hydraulic cylinder (hydraulic actuator) 102 as shown in FIG.

As shown in FIG. 6A, a hydraulic pump 103 is connected to the hydraulic cylinder 102, and the hydraulic oil supply direction from the hydraulic pump 103 is switched between the hydraulic cylinder 102 and the hydraulic pump 103. A valve 104 is interposed.
Further, an ECU (controller) 105 is electrically connected to the valve 104, and the operating state of the valve 104 is controlled based on a control signal from the ECU 105. Various sensors are connected to the ECU 105, and control signals for the valve 104 are transmitted based on the lateral acceleration (lateral G), steering angle (handle angle), vehicle speed, suspension stroke, and the like detected by these sensors. It is set up.

Then, by controlling the switching state of the valve 104, the expansion / contraction state of the hydraulic cylinder 102 is controlled, so that the twist state of the stabilizer body 101 is positively changed and the roll angle of the vehicle is controlled. It has become.
With such a configuration, as shown in FIG. 7 and FIGS. 8A and 8B, in a vehicle equipped with an active stabilizer, a vehicle equipped with a general stabilizer (see FIG. 7 and FIG. 8B “ Compared to “normal”, the roll angle of the vehicle body with respect to the lateral acceleration at the time of turning can be greatly suppressed, and the operability can be improved.
JP-A-6-234316

  By the way, it is known that when the vehicle body rolls by cutting the steering wheel from a straight traveling state, a so-called gyro moment is generated by rolling the front wheels that rotate at a high speed together with the vehicle body. This gyro moment acts in the direction of turning back the handle, and the magnitude of the gyro moment is proportional to the roll angular velocity. For this reason, the gyro moment acts as a steering reaction force, and the steering reaction force increases as the roll angular velocity increases.

On the other hand, in vehicles equipped with active stabilizers and active suspensions as described above, the suspension is controlled so that the roll angle of the vehicle is reduced when turning, so that the gyro moment and steering reaction force generated by the roll of the vehicle are small. Therefore, there is a problem that the stability of the vehicle is lowered due to this.
The present invention has been made in view of such problems, and to be compatible with and ensure stability of the roll restraining the vehicle of the vehicle, and an object thereof is to provide a roll control system for a vehicle.

The vehicle roll control system of the present invention, depending roll reduction also be operated to increase the role not only operates to suppress the roll generated in the vehicle, and increasing means, the traveling state of the said vehicle a control amount for the roll restraining or roll increases in output to the roll reduction, increasing unit includes a roll control means for controlling the operation of the roll reduction, increasing means Te, said roll control means, said in a low vehicle speed region roll restraining suppresses roll than the normal state without operating the increasing means, to so that increasing the roll than the normal state in the high vehicle speed region, that is configured to set the control gain for the control amount (Claim 1).

Another vehicle roll control system of the present invention, depending roll reduction also be operated to increase the role not only suppresses the roll generated in the vehicle, and increasing means, the traveling state of the said vehicle the roll reduction control amount for the roll restraining or roll increases Te, and outputs the increasing means includes a roll control means for controlling the operation of the roll reduction, increasing means, said roll control means is a low lateral acceleration zone the roll reduction, increases the roll than the normal state without operating the increasing means, in the high lateral acceleration region so as to suppress the roll than the normal state, and is configured to set the control gain for the control amount (Claim 2).

According to the vehicle roll control system of the present invention, in the low vehicle speed region to suppress the roll than the normal state, setting the control gain for the control amount so that increasing the roll than the normal state in the high vehicle speed range Therefore, in a low vehicle speed range, a vehicle motion characteristic with a reduced roll is obtained. Further, in the high speed range is utilized the stability improvement of the vehicle by the gyro moment in the steering back direction more actively-form, it is possible to ensure the stability of the vehicle (claim 1).

Further, according to another vehicle roll control system of the present invention, in the low lateral acceleration range increases the roll than the normal state, so as to suppress the roll than the normal state in the high lateral acceleration region, the Since the control gain with respect to the control amount is set low, in general, the reduction of the gyro moment in the switchback direction is suppressed in the low lateral acceleration range where the driver is not actively steering or the steering operation is relatively small. The stability of the vehicle can be ensured. In general, in a high lateral acceleration region, which is a region where there is a high demand for improvement in motion performance, the vehicle motion characteristics can be obtained with a reduced number of rolls (claim 2).

Hereinafter, the drawings and will be described vehicle roll control system according to a first embodiment of the present invention, FIG. 1 is a schematic diagram showing an overall structure.
As shown in the figure, this vehicle is provided with an active stabilizer (active stabilizer) 10 as a roll suppression and increase means that operates not only to suppress the roll angle of the vehicle but also to increase the roll. The active stabilizer 10 is configured in the same manner as that described with reference to FIGS. 6 to 8 in the background art section, and the stabilizer main body 1 interposed between the left and right suspensions (not shown) is provided. The roll angle is suppressed by positively controlling.

That is, as shown in the drawing, one end side of the stabilizer body 1 is connected to the suspension via a hydraulic cylinder (hydraulic actuator) 2, and the stabilizer is controlled by controlling the intake / exhaust state of the hydraulic oil to the hydraulic cylinder 2. The torsion angle of the main body 1 is controlled so that the roll state of the vehicle is controlled.
The active stabilizer 10 includes a hydraulic pump 3 that pressurizes the hydraulic oil, a valve 4 that is interposed between the hydraulic cylinder 2 and the hydraulic pump 3 and switches a supply direction of the hydraulic oil from the hydraulic pump 3; A controller (ECU) 5 for setting and outputting a control signal for the valve 4 is provided.

Although not shown, the ECU 5 detects a lateral acceleration sensor that detects lateral acceleration (lateral G), a steering angle sensor that detects a steering angle (handle angle), a vehicle speed sensor that detects vehicle speed, and left and right suspension strokes. A stroke sensor or the like is connected.
The ECU 5 sets a control signal for the valve 4 based on the information from the lateral acceleration sensor and sets a control gain for the control signal based on the information from the vehicle speed sensor. The state is to be controlled. Further, by controlling the switching state of the valve 4, the expansion / contraction state of the hydraulic cylinder 2 is controlled, and the twist state of the stabilizer body 1 is positively changed to control the roll angle of the vehicle. Yes.

Hereinafter, the control contents in the ECU 5 during turning will be described. The ECU 5 is provided with a control map as shown in FIG. This control map sets a vehicle body roll angle that is allowed with respect to the lateral acceleration acting on the vehicle at the time of turning, and the control amount for the valve 4 is obtained from the vehicle body roll angle set in this control map. It has become.
Here, three characteristics of high speed, medium speed, and low speed are set in this map, and even with the same lateral acceleration, different roll angles are set by changing the control gain according to the vehicle speed. ing.

This is mainly due to the following reasons. That is, to roll the front wheel also with vehicle body is rotating at a high speed when the roll, Jai Romo Mento occurs on the front wheel. This gyro moment acts as a steering reaction force, and the steering reaction force increases as the roll angular velocity increases.
However, in a vehicle equipped with the active stabilizer (roll suppressing means) 10 as described above, the roll angle of the vehicle is suppressed during turning, so that the gyro moment is reduced and the steering reaction force is also reduced accordingly. If the steering reaction force decreases in this way, the stability of the vehicle may decrease.

Therefore, in the vehicle roll control system according to this embodiment, the roll angle inhibition effects of the active stabilizer 10, in order to achieve both stability securing the vehicle, setting the roll angle characteristics as shown in FIG. 2 It is like that. In FIG. 2, the broken line indicates the roll characteristics in the normal state, that is, when the stabilizer body 1 is directly connected to the left and right suspensions without the actuator 2 being provided.

That is, in this embodiment, as shown in FIG. 2, the characteristics in the high vehicle speed range (high speed), the characteristics in the medium vehicle speed range (medium speed), and the characteristics in the low vehicle speed range (low speed) are set. It is set so as to approach the normal characteristic as the vehicle speed increases (that is, the control gain decreases).
Specifically, since the effect of the gyro moment is large in the high speed range, the control gain for the control signal set by the ECU 5 is set low to allow the roll to some extent. Then, by setting the control gain low in the high speed range in this way, it is possible to suppress a decrease in the gyro moment in the high speed range and to improve the stability of the vehicle.

Further, since the influence of the gyro moment is small in the low speed range, the control gain for the control signal set by the ECU 5 is set to be large so as to positively suppress the roll. As a result, it is possible to obtain a crisp motion characteristic in a low vehicle speed range.
In FIG. 2, characteristics at low speed (for example, 30 km / h), medium speed (for example, 50 km / h), and high speed (for example, 80 km / h) are mapped, but linear interpolation is performed from each characteristic at other speeds. and has Tsu name as roll angle and gain vehicle body is obtained, although such a setting is also conceivable, in the present embodiment, as shown in the control map of FIG. 4, a roll at a medium speed range and a low speed range Although it is suppressed, the roll angle is set to increase at high speeds .

The vehicle roll control system according to a first embodiment of the present invention, which is configured as described above, the first ECU 5, based on the detected information from the lateral acceleration sensor basic target roll angle of not shown Is set. A control gain is set based on detection information from the vehicle speed sensor. In the present embodiment, the gain is set to decrease as the speed increases.

  Then, the ECU 5 outputs the basic target roll angle multiplied by the gain as the final target roll angle, and sets the control information (control amount) for the valve 4 so as to be the target roll angle. Thereby, the expansion / contraction state of the hydraulic cylinder 2 is controlled, the state of the stabilizer body 1 is changed, and the roll angle of the vehicle is controlled. Specifically, the control gain is set low in the high speed range to allow rolls, and the control gain is set large in the low speed range to suppress rolls as much as possible.

  And by configuring in this way, it is possible to suppress a decrease in the gyro moment in the high speed range, so there is an advantage that the decrease in the steering reaction force in the high speed range is suppressed and the stability of the vehicle can be improved. Since rolling of the vehicle is suppressed, there is an advantage that it is possible to obtain a crisp motion characteristic at a low vehicle speed range. This also has the advantage that it is possible to achieve both vehicle roll suppression and vehicle stability ensuring. Further, the energy consumed for operating the active stabilizer 10 can be reduced, and there is an advantage that it contributes to improvement of fuel consumption.

Moreover, in the present embodiment, as shown in the control map of FIG. 4, the roll angle is normal in the middle speed range and the low speed range (that is, when the stabilizer body 1 is directly connected to the left and right suspensions without providing the actuator 2). The roll angle is set to be higher than that in the normal state in the high speed range.
When such a map is used, since the roll angle becomes larger in the high speed range, the gyro moment can be further increased, and the steering reaction force can be further increased to improve the stability of the vehicle. In addition to being able to do so, it also has the effect of promoting safe driving.

Referring next to the vehicle roll control system according to a second embodiment of the present invention, in this second embodiment, the control map shown in FIG. 5 is provided instead of the control map shown in FIG. 4 Only this point is different from the first embodiment.
Here, in the control maps shown in FIGS. 3 and 5, the broken lines indicate the roll characteristics in the normal state, that is, when the stabilizer body 1 is directly connected to the left and right suspensions without providing the actuator 2 as in the first embodiment. Yes.

In FIG. 3, which is a reference diagram of the second embodiment, the control gain is set low in the region where the lateral acceleration is low as shown by the solid line, and the characteristic is set to be relatively close to the normal state. Further, in a region where the lateral acceleration is high, the control gain is set high. Specifically, in a region of a predetermined lateral acceleration (0.2 G) or less, the inclination of the vehicle body roll angle with respect to the lateral acceleration is set to a value close to normal (that is, the gain is set low), and is equal to or greater than the predetermined lateral acceleration. In the region, the inclination is set to be small (the gain is large), and such a setting is also conceivable. However, in the present embodiment, as shown in the map of FIG. The control gain is set low so that the roll angle is larger than in the state, and in a high lateral acceleration region that is equal to or greater than the predetermined lateral acceleration, a large control gain is set so as to suppress the roll angle than in the normal state .

This is because the effect of the gyro moment is greater in the low lateral acceleration region where the driver is not actively steering. For this reason, in a region where the lateral acceleration is small (or a region where the steering wheel angle or yaw rate is small), the control gain is set low to allow the roll.
In addition, the high lateral acceleration region is a region where there is a high demand for improvement in motion performance, and it is a region where the influence of the gyro moment is small. I am trying to do it.

The vehicle roll control device according to a second embodiment of the present invention, which is configured as described above, is also compatible with and ensure stability of the roll restraining the vehicle of the vehicle as in the first embodiment There are advantages that can be made. That is, in the low lateral acceleration region, the roll is allowed and the reduction of the gyro moment is suppressed, whereby the reduction of the steering reaction force is suppressed, and there is an advantage that the stability of the vehicle can be improved. Moreover, in the area | region where a lateral acceleration is more than predetermined value, there exists an advantage which can suppress the roll positively and can obtain the vehicle motion characteristic made into the millet.
In particular, as shown in the map of FIG. 5, in the low lateral acceleration region below the predetermined lateral acceleration, the control gain is set low so that the roll angle is larger than in the normal state, and in the high lateral acceleration region above the predetermined lateral acceleration, Since the roll angle is set to a large control gain so as to suppress the roll angle compared to the normal state , the roll angle becomes large in the low lateral acceleration region, but a larger steering reaction force can be obtained accordingly, and the vehicle stability Can be further enhanced.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the case where the active stabilizer is applied as the roll suppressing unit has been described. However, an active suspension may be applied as the roll suppressing unit .

Is a schematic diagram showing an overall configuration of a vehicle roll control system according to a first embodiment of the present invention. It is a diagram for explaining the control characteristics of the vehicle roll control system according to a first embodiment of the present invention. It is a diagram for explaining the control characteristics of the vehicle roll control system according to a second embodiment of the present invention. It is a diagram for explaining the control characteristics of the vehicle roll control system according to a first embodiment of the present invention. It is a diagram for explaining the control characteristics of the vehicle roll control system according to a second embodiment of the present invention. (A) is a figure for demonstrating the whole structure of an active stabilizer, (b) is a schematic diagram shown about the principal part structure. It is a figure which shows the characteristic of an active stabilizer. (A), (b) is a figure for demonstrating the effect | action of an active stabilizer.

Explanation of symbols

1 Stabilizer body 2 Hydraulic cylinder (hydraulic actuator)
5 ECU (roll control means)
10 Active stabilizer (roll suppression means)

Claims (2)

Roll suppression and increase means that operate not only to suppress the roll generated in the vehicle but also to increase the roll;
Controlled variable the roll restraining for roll restraining or roll increases according to the running state of the said vehicle, the roll restraining output increasing means includes a roll control means for controlling operation of increasing means,
The roll control means, the roll reduction in the low vehicle speed range, to suppress the roll than the normal state without operating the increasing means, to so that increasing the roll than the normal state in the high speed range, the control for the controlled variable characterized in that it is configured to set the gain, roll control system for a vehicle. Roll suppression and increase means that operate not only to suppress the roll generated in the vehicle but also to increase the roll;
Controlled variable the roll restraining for roll restraining or roll increases according to the running state of the said vehicle, the roll restraining output increasing means includes a roll control means for controlling operation of increasing means,
The roll control means increases the roll in a normal state where the roll suppression and increase means are not operated in a low lateral acceleration range, and suppresses the roll in the high lateral acceleration range than in the normal state . characterized in that it is configured to set the control gain, roll control system for a vehicle.

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