JP4353041B2 - Steering reaction force control device for vehicle - Google Patents

Description

  The present invention relates to a vehicle steering reaction force control apparatus suitable for use in a vehicle capable of assisting steering force.

Conventionally, so-called active suspension (hereinafter abbreviated as active suspension) and active stabilizer (hereinafter abbreviated as active stabilizer), which actively operate vehicle suspensions, are widely known, and 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.

  2A and 2B are schematic diagrams showing the system configuration of the active stabilizer, FIG. 3 is a diagram showing the characteristics thereof, and FIGS. 4A and 4B are diagrams showing the operation thereof. In FIG. 2A, 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.

Further, as shown in FIG. 2A, a hydraulic pump 103 is connected to the hydraulic cylinder 102, and a 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. 3 and FIGS. 4A and 4B, in a vehicle equipped with an active stabilizer, a vehicle equipped with a general stabilizer (see FIG. 3 and FIG. 4B “ 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 was devised in view of such a problem, and an object of the present invention is to provide a vehicle steering reaction force control device capable of ensuring the stability of a vehicle without impairing the effect of roll suppression control. And

The vehicle steering reaction force control apparatus according to the present invention includes a steering reaction force adjusting means provided so as to be able to adjust a steering reaction force acting on a steering system during vehicle steering, and a roll suppression that operates to suppress a roll generated in the vehicle. Means, a roll suppression means for controlling the operation of the roll suppression means by outputting a control amount for roll suppression to the roll suppression means according to the running state of the vehicle, and the increase according to the increase in the control amount. Steering reaction force control means for controlling the operation of the steering reaction force adjusting means so as to increase the steering reaction force , and the steering reaction force control means reduces the gyro moment on the steered wheel based on the control amount. By calculating the compensation amount to be compensated and increasing the steering reaction force in accordance with the compensation amount, the roll suppression control is executed on the steering system when the roll suppression control is executed. As the steering reaction force equivalent to the time have acts, it is characterized by controlling the operation of the steering reaction force adjustment means.

  The steering reaction force adjusting means is preferably an actuator of a power steering device that assists the steering force of the vehicle.

According to the vehicle steering reaction force control apparatus of the present invention, since the steering reaction force of the control amount that compensates for the decrease in the gyro moment accompanying the increase of the control amount for roll suppression is increased, it is stable regardless of the roll angle suppression control Thus, there is an advantage that the turning performance can be improved by suppressing the roll while ensuring the steering stability of the vehicle and the ease of driving.

Hereinafter, a vehicle steering reaction force control apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an overall configuration thereof.
As shown in the figure, this vehicle steering device is provided with an electric power steering device (hereinafter referred to as EPS) 20 that assists the steering force by the driving force of a motor (steering reaction force adjusting means) 21. Here, in addition to the motor 21 described above, the EPS 20 is provided with a torque sensor 22 capable of detecting a steering force and a controller (EPS-ECU) 23 for setting a control signal for the motor 21. In the EPS-ECU 23, the basic steering assist amount S1 is set based on the steering torque detected by the torque sensor 22, the vehicle speed detected by a vehicle speed sensor (not shown), or the like.

  In addition, this vehicle is provided with an active stabilizer (active stabilizer) 10 as roll restraining means for restraining the roll angle of the vehicle as shown in the figure. The active stabilizer 10 is configured in the same manner as that described with reference to FIGS. 2 to 4 in the background art section, and includes a stabilizer body 1 interposed between left and right suspensions (not shown). 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 (active stabilizer ECU) 5 for setting and outputting a control signal for the valve 4 is provided.

Although not shown, the active stabilizer ECU 5 includes 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 for detection is connected.
In the active stabilizer ECU 5, a control signal for the valve 4 is set based on the information from each of the sensors, and the switching state of the valve 4 is 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.

By the way, in the present apparatus, the control amount of the EPS 20 is set in consideration of the control information of the active stabilizer 10 (that is, the control amount of the roll suppression control), and thereby the steering stability is greatly improved. ing.
That is, as shown in FIG. 1, the control information set by the active stabilizer ECU 5 (hereinafter referred to as active stabilizer control information) is also output to the EPS-ECU 23, and the EPS-ECU 23 A steering assist correction amount (steering reaction force) S2 corresponding to roll suppression control is calculated separately from the basic steering assist amount S1 based on the stabilizer control information. Here, the steering assist correction amount S2 is set so as to increase the steering reaction force in accordance with an increase in the control amount of the roll suppression control.

The EPS-ECU 23 outputs the assist amount obtained by adding the basic steering assist amount S1 and the steering assist correction amount S2 corresponding to the roll suppression control to the motor 21 as a final control amount.
This is mainly due to the following reasons. That is, when the vehicle body rolls, the front wheels 11 and 12 that rotate at high speed also roll together with the vehicle body, so that a gyro moment is generated in the front wheels 11 and 12. 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 steering reaction force control apparatus according to the present embodiment, by controlling the output of the motor 21 of the EPS 20 so that the steering reaction force equivalent to when the roll angle suppression control is not performed on the steering system, The EPS 20 compensates for the gyro moment that decreases due to the roll angle suppression control, thereby ensuring the operability of the vehicle.

Specifically, the active stabilizer control information output from the active stabilizer ECU 5 to the EPS-ECU 23 includes a control amount for reducing the roll angle when the roll suppression control is executed. This control amount is calculated in the active stabilizer ECU 5 based on the lateral G, the steering wheel angle, the vehicle speed, and the like.
On the other hand, the EPS-ECU 23 is provided with a map or calculation formula for obtaining a correction amount that compensates for a decrease in gyro moment based on control amount information for roll angle reduction from the active stabilizer ECU 5.

  Then, the EPS-ECU 23 calculates a correction amount that compensates for the decrease in the gyro moment, and sets it as the steering assist correction amount S2. The EPS-ECU 23 calculates a final steering assist amount S (= basic steering assist amount S1 + steering assist correction amount S2 corresponding to roll suppression control) and outputs it to the motor 21. Note that the steering assist amount S1 is an assist amount in the steering direction, but the steering assist correction amount S2 acts as a steering reaction force, and thus is an assist amount in the direction opposite to the steering direction.

  Since the vehicle steering reaction force control apparatus according to the embodiment of the present invention is configured as described above, first, the active stabilizer ECU 5 includes a lateral acceleration sensor, a steering angle sensor, a vehicle speed sensor, a stroke sensor, and the like (not shown). A target roll angle is set based on the detection information, and control information (control amount) for the valve 4 is set 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.

  On the other hand, in the EPS-ECU 23, the basic steering assist amount S1 is set based on the steering torque detected by the torque sensor 22, the vehicle speed detected by the vehicle speed sensor, or the like. Further, in the EPS-ECU 23, based on the control amount for reducing the roll angle from the active stabilizer ECU 5, the correction amount of the steering assist amount that compensates for the decrease in the gyro moment is set as the steering assist correction amount S2 corresponding to the roll suppression control. .

Then, the EPS-ECU 23 adds the basic steering assist amount S1 and the steering assist correction amount S2 corresponding to the roll suppression control to calculate the final steering assist amount S and outputs it to the motor 21.
Therefore, the vehicle steering reaction force control apparatus according to the embodiment of the present invention has an advantage that the stability of the vehicle can be ensured without impairing the effect of the roll angle suppression control. That is, since the decrease in the steering reaction force accompanying the roll angle suppression is compensated by the ESP 20, a stable steering reaction force can be obtained regardless of the roll angle suppression control, thereby improving the stability of the vehicle. In addition, it is possible to avoid a situation in which the steering reaction force decreases due to the roll angle suppression control and the driver feels uncomfortable.

Further, since the steering reaction force is compensated using the motor 21 of the EPS 20, it is not necessary to newly provide an actuator or the like, and it is only necessary to add a control logic, so that an increase in cost and weight can be suppressed.
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 an active stabilizer is applied as the roll suppressing unit has been described. However, an active suspension may be applied as the roll suppressing unit. In addition to the EPS 20 motor 21 described above, for example, a hydraulic cylinder (actuator) of a hydraulic power steering device may be applied as the steering reaction force adjusting means, or the steering reaction force adjusting means may be a power steering device. You may provide independently.

  Further, the roll suppression by the roll suppressing means may not only reduce the amount of roll in the normal direction originally generated in the vehicle, but also generate a roll in the reverse direction.

1 is a schematic diagram showing an overall configuration of a vehicle steering reaction force control apparatus according to an 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 Active stabilizer ECU (roll control means)
10 Active stabilizer (roll suppression means)
20 EPS (electric power steering device)
21 Motor (steering reaction force adjusting means)
23 EPS-ECU (steering reaction force control means)

Claims (2)

A steering reaction force adjusting means provided to be capable of adjusting a steering reaction force acting on the steering system during vehicle steering;
Roll restraining means that operates to restrain rolls generated in the vehicle;
Roll control means for controlling the operation of the roll suppression means by outputting a control amount for roll suppression to the roll suppression means in accordance with the traveling state of the vehicle;
Steering reaction force control means for controlling the operation of the steering reaction force adjustment means so that the steering reaction force increases in response to an increase in the control amount ,
The steering reaction force control means is
Based on the control amount, a correction amount that compensates for a decrease in the gyro moment on the steered wheels is calculated,
By increasing the steering reaction force in accordance with the correction amount, a steering reaction force equivalent to that when the roll suppression control is not executed is applied to the steering system when the roll suppression control is executed. A vehicle steering reaction force control device for controlling the operation of the steering reaction force adjusting means . 2. The vehicle steering reaction force control device according to claim 1, wherein the steering reaction force adjusting means is an actuator of a power steering device that assists the steering force of the vehicle.

Images