JPH03510A - Controller for suspension or stabilizer - Google Patents

Abstract

PURPOSE:To restrain shock and vibration, and restrain in the shortest time the worsening of a riding comfortability due to a mistaken decision, at the above device for a vehicle, by arranging so that a characteristic such as the force of damping may be changed to a desired value on the basis of the size of the acceleration of a carbody or this acceleration continuance time which is more than a predetermined level. CONSTITUTION:When an up and down direction acceleration detected by means of an acceleration sensor 2 is inputted into a controller 7, whether or not this is a desired acceleration whose size is more than a predetermined one in an up and down direction with a reference point as a border, is decided. And, when it is decided that its size is more than the predetermined one, the force of damping is set at a middle value by means of a damping force change means 4, and a predetermined time retention is made. And, the measuring of the continuance time of the acceleration whose level is more than a predetermined one, is made, and a decision to continue or change the force of damping is made at the time of the completion of the measuring, and continuation or a return to weaken the force of damping is conducted. As a result, shock and vibration is prevented, and the worsening of a riding comfortability due to a mistaken decision can be speedily restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspension or stabilizer J'B control device that is effective in suppressing vehicle body vibration.

[Conventional technology]

Devices have been developed that control changes in the damping force and spring constant of shock absorbers installed between the wheels and the vehicle body, as well as the characteristics of stabilizers, depending on the vehicle posture or the condition of the road surface on which the vehicle is traveling. ing.

Regarding the vehicle posture, for example, during sudden starts, sudden braking, and slalom, the damping force of the shock absorber is increased to a large value to maintain a smooth stance.

There are devices that perform control to suppress the occurrence of dives and rolls.

Additionally, when driving on good roads, the damping force of the shock absorber is changed to a large value to improve maneuverability and stability, while when driving on rough roads, the damping force of the shock absorber is changed to a medium value. There is also a device that performs control to suppress vibration while maintaining a good riding comfort.

As the above-mentioned device, the present applicant has previously applied for an “automobile suspension system” (Japanese Patent Application Laid-Open No. 60-47709).
etc. have been proposed.

That is, the duration of the vibration acceleration exceeding a predetermined value is measured, and the damping force is increased or the spring constant is increased (switched) only when this duration continues for a predetermined judgment time or longer.

[Problem to be solved by the invention]

By the way, in the above-mentioned conventional example, the deterioration of ride quality caused by the vehicle body vibrating vertically near the sprung mass resonance frequency due to vibration input from the road surface, for example, can be prevented for a duration exceeding a predetermined acceleration value, for example, due to the sprung mass resonance. If you try to tightly control the suspension characteristics by setting detection near the half period, it will be difficult to control the suspension characteristics unless at least half the period of the determination frequency near the sprung mass resonance frequency has elapsed. Judgment cannot be made and control is delayed.

For example, there has been a drawback that it is difficult to appropriately suppress the initial large body shock and large changes in the attitude of the vehicle body that occur when driving over a large bump.

Similarly, whether the vehicle is driving on a rough road is detected by the frequency components of the unsprung vibration of the vehicle body, as well as vertical or horizontal vibration patterns, and the characteristics of the suspension or stabilizer are changed to medium values. , even when executing control to maintain good ride comfort and good ground contact on rough roads, the control is executed even on rough roads until the reliable vibration frequency determination or vibration pattern determination for a predetermined period of time is completed. The drawback was that it couldn't be done.

In other words, at the initial level of vehicle body vibration, it is unclear whether this vibration should stiffen the suspension or stabilizer characteristics, or if something in between is best, and the optimal control parameters can be determined only from vibration frequency information. It takes time to determine the waveform after that, and if the waveform of the vibration is a complex combination of sprung and unsprung vibrations, the method disclosed in Japanese Patent Application Laid-open No. 8010/1983 As such, subsequent determinations may also be incomplete, and there may be a problem in which the determination is further delayed.

This invention was made to solve the above-mentioned problems, and it can accurately suppress the shock and unnecessary vibrations of the car body even when driving over a large protrusion, and it also prevents the deterioration of riding comfort caused by incorrect judgment. An object of the present invention is to obtain a control device for a suspension suspension or a stabilizer that can suppress the damage in the shortest possible time.

[Means to solve the problem]

The suspension or stabilizer control device according to the present invention provides a damping force, a spring constant, and a torsional force based on the magnitude of acceleration in at least one of the vertical direction or the horizontal direction of the vehicle body, or the duration of this acceleration at a predetermined level or more. A control device is provided to change any one of the values to a desired value.

[For production]

The control device according to the present invention reduces the spring constant, damping force, and torsional force (one of which is a 1, and increase the spring constant, damping force, and torsional force (one of them to the first
, or change and maintain it at a second desired level.

〔Example〕

Embodiments of the suspension or stabilizer control device of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the basic configuration of one embodiment of the present invention, and the present invention is constituted by the members shown in FIG.

That is, an acceleration detection means 2 that detects acceleration in one or both of the vertical and horizontal directions of the vehicle body 1 and the damping force of the suspension disposed between the wheels 3a, 3b and the vehicle body 1 are externally detected. The damping force changing means 4 changes the damping force according to the command, or the spring constant changing means 5 changes the spring constant (for example, according to the method of
9 and Japanese Patent Application Laid-Open No. 60-240511), or torsional force changing means 6 for changing the torsional force of the stabilizer disposed between the wheels 3a and 3b (for example, disclosed in Japanese Patent Application Laid-Open No. 60-240511). 63-25119, Japanese Unexamined Patent Publication No. 63-28709, etc.), the magnitude of the acceleration is determined, and the duration of the acceleration exceeding a predetermined level is determined, and the magnitude or duration of the acceleration is determined. Based on this, a command to change one of the damping force, spring constant, and stabilizer torsional force to a desired value is issued to at least one of the damping force changing means 4, the spring constant changing means 5, and the stabilizer torsional force changing means 6. It is composed of a control device 7 that is sent to the

Note that these damping force changing means 4 and spring constant changing means 5
, the stabilizer torsional force changing means 6 are collectively referred to as variable means.

Fig. 2 shows the configuration of an embodiment in which the present invention is applied to switching the damping force, and is a perspective view of the above-mentioned components mounted on a vehicle, and Fig. 3 is a block diagram showing the configuration. be.

In both FIG. 2 and FIG. 3, 11 is a steering sensor that detects the operational status of the steering wheel, 12 is a vehicle speed sensor, 13 is an accelerator opening sensor that detects acceleration/deceleration operations of the vehicle body 1, and 14 is a steering wheel sensor that detects the operation status of the steering wheel. 15 is a select switch, and 16 is a display.

The outputs of the steering sensor 11, vehicle speed sensor 12, accelerator opening sensor 13, brake switch 14, and select switch 15 are input to the control device 7, and the control device 7 controls the damping force changing means 4 and the display 16. It looks like this.

The acceleration detection means 2 is a vertical acceleration sensor that detects the acceleration of the vehicle body 1 in the vertical direction, and is, for example, an acceleration pickup made of a piezoelectric material, or a differential transformer type.
Alternatively, a semiconductor strain gauge type acceleration sensor for automobiles is used.

In this embodiment, the acceleration sensor 2 detects vertical and horizontal acceleration, and will be referred to as an acceleration sensor 2 hereinafter. Although the acceleration sensor 2 is installed at the center of gravity of the vehicle body 1, it may be installed at the tip, at the front and rear, or at each suspension of each wheel.

Further, this acceleration sensor 2 linearly outputs acceleration in the vertical or horizontal direction individually as an analog voltage around the output level at zero acceleration.

The output of the acceleration sensor 2 that detects vertical or horizontal acceleration is individually A/D (analog/digital) converted and input to a control device 7 composed of a microcomputer, which controls the signal level of the acceleration sensor 2 and changes. The duration is calculated for each.

Next, the processing procedure of the control device 7 will be explained according to the flowchart of FIG.

First, in step 31, the signal of the acceleration sensor 2 that detects vertical or horizontal acceleration is read, and in step S2, the signal is moved in the vertical or horizontal directions from the desired reference point (±OG (acceleration)). The magnitude of the acceleration that is greater than or equal to the first predetermined magnitude is determined.

In step S3, the duration of the acceleration greater than or equal to the second desired magnitude is determined by, for example, a timer (not shown, but the control device 7
(included in).

Based on the determination results in steps S2 and 33, step S4
If it is determined that an acceleration equal to or greater than the first predetermined magnitude has occurred (YES), the suspension damping force, spring constant, and stabilizer torsional force are adjusted to the mizoia (
rMEDJ) In other words, set it to an intermediate value, and
A timer for maintaining this state is set at a predetermined time to start counting.

If rNOJ is determined in step S4, the process goes to step S6 (in this step S6, it is determined whether or not a timer that increases and maintains the damping force, etc. is already in operation, and
If NOJ, damping force, spring constant,
Soften the torsional force of the stabilizer (rsOFTJ)
, that is, to return to the basic software state.

In addition, in step S6, if the damping force is increased and maintained, in step S7 the duration of the acceleration above a predetermined level has been measured, and the misoia (rM
It is determined whether the conditions for increasing the current state of EDJ) to hard (rHARDJ) are satisfied.

As a result of this determination, if rYEsJ, that is, the duration of the acceleration equal to or greater than the second predetermined magnitude is the vertical acceleration, the predetermined value corresponding to the acceleration of vibration near the sprung mass resonance of the vehicle body 1 is determined. If so, in step S8 the current state of Mizoia (rMEDJ) is changed to hard (rHARDJ).
, set the hardware retention timer to a predetermined time, and start counting.

Further, if the result of the determination in step S7 is that the duration of the acceleration equal to or greater than the second predetermined magnitude is acceleration in the left-right direction, the determination is made based on whether or not it corresponds to resonance of the vehicle body in the yaw direction or the roll direction. do.

If it is rNOJ in this step S7, the duration of the acceleration signal has been measured in step S9, and the damping force, spring constant,
It is determined whether the conditions for maintaining the torsional force of the stabilizer are satisfied, and whether the level of the predetermined vibration magnitude of vertical or horizontal acceleration is medium, or the duration of the vibration is due to unsprung resonance of the vehicle body 1. Or, if it is a predetermined value corresponding to the lateral acceleration of the vehicle body due to a rough road, the damping force or other parameters are adjusted to Misoia (rMED) in step S10.
J) and set or reset the Mizoia retention timer.

If "NO" in step S9, the process proceeds to the next step without changing the current state.

In the above embodiments, the characteristics of the suspension or stabilizer were explained using three-stage control, but it goes without saying that similar effects can be expected even with more stages.

Furthermore, although the description has been made with one acceleration sensor 2, the characteristics of the suspension or stabilizer corresponding to the detected acceleration may be similarly controlled even if there are two acceleration sensors 2 or each wheel.

Further, although the description has been made mainly with an acceleration sensor that detects vertical acceleration, it goes without saying that similar effects can be obtained in rolling and stabilizer control even if the acceleration sensor detects lateral acceleration.

Furthermore, if the determination in step S4 is made to be at least a predetermined third duration and at least a predetermined magnitude of acceleration, it will be more effective to remove transient shocks such as noise, and It goes without saying that the effects of this invention can be enhanced.

[Effects of the Invention] As described above, according to the present invention, the damping force of the suspension, the spring constant, or the torsional force of the stabilizer is increased depending on the magnitude of the acceleration in the vertical or horizontal direction of the vehicle body. The control device is configured so that when the duration of the acceleration of the vehicle body after increasing the acceleration is equal to or higher than a predetermined level is measured, the increased state is changed to w1 continuation or changed, and then returned to w1 continuation or the basic weak state. With a simple configuration, even when driving over a large bump, the shock and unnecessary vibration of the vehicle body caused by control delays are suppressed accurately by eliminating the delay, and the deterioration of ride comfort caused by incorrect judgment is suppressed in the shortest possible time. This has the advantage of being able to provide a suspension or stabilizer control device that can control the suspension or stabilizer.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of a suspension or stabilizer control device according to an embodiment of the present invention, and Fig. 2 shows each component of an embodiment in which the present invention is applied to damping force switching. A perspective view of the state installed on the
FIG. 3 is a block diagram showing the configuration of the embodiment shown in FIG.
2 is a flowchart showing the flow of operation of the control device in the embodiment of FIGS. 2 and 3. FIG. DESCRIPTION OF SYMBOLS 1... Vehicle body, 2... Acceleration detection means, 3a, 3b.
... Wheel, 4... Damping force changing means, 5... Spring constant changing means, 6... Stabilizer torsion force changing means, 7
···Control device. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] Acceleration detection means for detecting at least one of the acceleration in the vertical direction or the horizontal direction of the vehicle body, and at least one of the spring constant or damping force of the vehicle suspension, or the torsional force of the stabilizer, is variable in three or more stages. a variable means, and at least one of the spring constant, damping force, and torsional force according to the magnitude of the acceleration in at least one of the vertical direction or the horizontal direction from the reference level of the output signal of the acceleration detection means is equal to or higher than a predetermined level. is increased to a first desired level, and at least one of the spring constant, damping force, and torsional force is increased to the first desired level depending on the duration of the output signal of the acceleration detection means being at or above the predetermined level.
A control device for a suspension or stabilizer, comprising: a control device for controlling the variable means so as to maintain the variable means at a desired level, or change and maintain the variable means to a second desired level.