KR930009380B1 - Controller for suspension stabilizer - Google Patents

Abstract

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Description

Suspension Control Device

1 is a diagram showing the basic configuration of a suspension control apparatus according to an embodiment of the present invention.

2 is a perspective view of a state in which each component of the embodiment is mounted on a vehicle body when applied to the switching of the damping force of the present invention.

3 is a block diagram showing the configuration of the embodiment of FIG.

4 and 5 are flowcharts showing the flow of operation of the control apparatus in the embodiment of FIGS. 2 and 3.

* Explanation of symbols for main parts of the drawings

1: vehicle body 2: acceleration detection means

3a, 3b: wheel 4: damping force variable stage

5: Spring constant variable stage 6: Stabilizer torsional force variable means

7: controller

The present invention relates to an effective suspension control device for suppressing vehicle body vibrations.

Background Art [0002] In the past, a device has been developed for changing and controlling the damping force, spring constant, and the characteristics of the shock absorber attached between the wheel and the vehicle body depending on the attitude of the vehicle or the road surface on which the vehicle is traveling. Regarding the attitude of the vehicle, for example, the damping force of the shock absorber is set to a large value during sudden start, sudden braking, slalom, and the like, such as squat, dive, and roll. There is an apparatus for performing control to suppress the occurrence.

In addition, when driving on a good road, the damping force of the shock absorber is changed to a large value, and the adjustment and stability are improved, while when driving on a bad road, the damping force of the shock absorber is set to a medium value. There is also a device that changes the weight, improves the riding comfort and suppresses vibration.

As such a device, there has been proposed a "suspension device for automation" (Japanese Patent Laid-Open No. 60-47709) filed by the present applicant.

According to this, the apparatus measures the duration at which the acceleration of the vibration becomes equal to or greater than the predetermined value and increases the damping force only when the duration lasts for the predetermined determination time or switches the spring constant to a large value.

By the way, in the above-mentioned conventional example, the weakening of the ride feeling that occurs when the vehicle body vibrates up and down near the upper resonance frequency of the spring by vibrating input by the road surface, for example, has a duration of a predetermined acceleration value or more, for example, a spring. Determination of control of the characteristics of the suspension when at least half-cycle time of the determination frequency near the upper resonance frequency of the spring is not passed when the detection is made to be set near the semi-period of the upper resonance and the control of the suspension characteristic is made hard. Cannot be controlled and control is delayed.

For example, there was a drawback that it was difficult to adequately suppress the large posture change of the vehicle itself or the initial big impulse that occurred in the case of crossing a large projection.

In the same way, it is detected whether the vehicle is driving on a bad road by the frequency component of the vibration of the lower part of the body of the vehicle or the vibration pattern on the top, bottom, left and right sides, and the suspension characteristic is changed to a medium value. Even in the case of carrying out a control for maintaining a satisfactory condition, there is a drawback that control cannot be performed even on a bad road until the determination of the vibration frequency pattern or the vibration pattern is completed at a predetermined time.

That is, at the initial vibration level, it is not known whether the vibrations should each have a suspension characteristic of hard or medium, and determine the optimal control parameter only by the frequency information of the vibrations. It takes time, and even in the case of the subsequent waveform, in the case of the vibration in which the waveform of the vibration overlaps the upper and lower vibrations of the spring, the subsequent determination is also incomplete, as disclosed in Japanese Patent Laid-Open No. 63-8010. This slower downside is also conceivable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and even when a large projection is exceeded, it is possible to reliably suppress the impact of the vehicle body and unnecessary vibration, and further to suppress the deterioration of the riding comfort caused by the misjudgment in the shortest time. It is an object of the present invention to obtain a suspension control device.

The suspension control device according to the present invention is a value that is one of a damping force, a spring constant, and a torsional force depending on the magnitude of the acceleration in at least one of the vertical direction and the left and right directions of the vehicle body, or the duration of the predetermined level or more of the acceleration. Equipped with a control unit to change the

In addition, the suspension control apparatus according to the present invention determines the magnitude of the derivative value with respect to the signal of at least one of the up-down direction or the left-right direction of the vehicle body, determines the duration of the acceleration level or more by a predetermined level, and determines the magnitude of the derivative value of the acceleration. Etc., a control device is provided for sending a command for changing at least one of the damping force of the suspension, the spring constant, or the torsional force of the stabilizer to a desired value, and then changing it according to the duration. The control device according to the present invention raises at least one of the spring constant, the damping force, and the torsional force to the first desired level according to the magnitude of the acceleration of at least one of the up, down, left and right directions of the vehicle body from the reference value to a predetermined level or more. At the same time, at least one of the spring constant and the torsional force is maintained at the first desired level or changed to the second desired level in accordance with the duration of the acceleration above the predetermined level.

In addition, the control device of the present invention raises at least one of the damping force, the spring constant, and the torsional force to the first desired level in accordance with the derivative value of the acceleration signal, and at the same time, the damping force according to the duration of the predetermined level or more of the acceleration signal. At least one of the spring constant and the torsional force is maintained at the first desired level, or is changed to the second desired level.

Next, an embodiment of the suspension control apparatus of the present invention will be described 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 this FIG. That is, the acceleration detection means 2 which detects one of the upper and lower sides and the left and right sides of the vehicle body 1 or the two accelerations in both directions, and the suspension attached between the wheels 3a and 3b and the vehicle body 1, respectively. Damping force variable stage 4 for changing the damping force according to an instruction from the outside, or spring constant variable stage 5 for changing the spring constant (for example, Japanese Patent Application Laid-Open No. 60-47709, Japanese Patent Laid-Open No. 60-240511). Torsion force varying means 6 (for example, Japanese Patent Application Laid-Open No. 63-25119) for changing the torsional force of the stabilizer attached between the wheels 3a and 3b. Publication, Japanese Patent Application Laid-Open No. 63-28709, etc.), the determination of the magnitude of acceleration, and the determination of the duration of time above a predetermined level of acceleration, respectively, and the damping force, the spring constant, and the stabilization according to the magnitude or duration of the acceleration. Hope at least one of my non-flame forces Is composed of a control device 7 which outputs a command to change the value to at least one of the damping force variable stage 4, the spring constant variable stage 5, and the torsional force varying means 6 of the stabilizer.

The damping force variable stage 4, the spring constant variable stage 5, and the torsional force varying means 6 of the stabilizer are collectively referred to as variable means.

FIG. 2 shows the configuration of the embodiment in the case where the present invention is applied to the damping force switching method, and is a perspective view in which the corner member is mounted on a vehicle, and FIG. 3 is a block diagram showing the configuration. In Fig. 2 and Fig. 3, 11 is a steering sensor that detects the handle of a handle, 12 is a vehicle speed sensor, 13 is an accelerator opening sensor that detects acceleration and deceleration of the vehicle body 1, 14 is a brake. Switch, 15 is a selector switch, and 16 is an indicator.

The outputs of these steering sensors 11, vehicle speed sensors 12, accelerator opening sensors 13, brake switches 14, selection switches 15 are input to the control device 7, and the control device 7 By this, the damping force variable stage 4 and the indicator 16 are controlled. The acceleration detecting means 2 is a vertical acceleration sensor that detects the acceleration in the vertical direction of the vehicle body 1, and for example, an acceleration pickup for automobiles of an acceleration pick-up constituted by a piezoelectric body, a differential transformer type, or semiconductor strain strain control It is used. In this embodiment, the acceleration is detected up, down, left and right, and henceforth, the acceleration sensor 2 is called. Although the mounting position of this acceleration sensor 2 was set as the center position of the vehicle body 1, you may mount in the front-end position, two places before and behind, or every suspension of each wheel.

In addition, this acceleration sensor 2 outputs linear acceleration by an analog voltage separately from the acceleration in the up, down, left, and right directions centering on the output level at zero acceleration.

The output of the acceleration sensor 2 which detects the accelerations up, down, left, and right is individually A / D converted and input to the control device 7 composed of a microcomputer, so that the signal level and the change duration of the acceleration sensor 2 are Are computed respectively.

Next, the processing procedure of the control apparatus 7 is demonstrated according to the flowchart of FIG.

First, in step S1, the signal of the acceleration sensor 2 which detects the acceleration of up, down, left and right, is read, and the step S2 is based on the desired reference point {± OG (acceleration)} of the signal. The acceleration magnitudes in the up, down, left and right directions are respectively determined. In step S3, the duration of the acceleration above the desired value is determined by, for example, a timer (not shown in the control device 7 although not shown). On the basis of the determination result of the staff S2, if it is determined that the acceleration of the first predetermined value or more has occurred in step S4 (YES), the damping force of the suspension, the spring constant, and the torsional force of the stabilizer are medium in step S5. ("MED"), i.e., it is set to the intermediate value which is the first predetermined level, and at the same time, a timer is set to start counting to maintain this state.

In addition, if it determines in step S4, it bypasses "No" and advances to step S6. In this step S6, it is determined whether the damping force or the like is already maintained at MED or HARD, that is, whether the timer held at MED or HARD is active. If "NO", the damping force, spring constant, The torsional force of the stabilizer is returned to soft ("SOFT"), the basic soft state.

In step S6, if the damping force or the like is maintained at a high level, i.e., if the holding time of the MED or HARD remains, the current state of the medium ("MED"), which is the first predetermined level, is set to the second predetermined level. "HARD") determines whether the height is satisfied. In other words, it is determined whether the acceleration of the second predetermined value or more continues for a predetermined time.

As a result of this determination, if "YES", i.e., the duration of the acceleration above the second predetermined value is the vertical acceleration, for example, if the vehicle body 1 is a predetermined value corresponding to the acceleration of the vibration near the spring upper resonance frequency, In step S8, the state of the current first predetermined level medium ("MED") is changed to the second predetermined level hard ("HARD"), and the timer for hard holding is set at a predetermined time to start counting. .

If the determination result in step S7 is that the duration of the acceleration above the second predetermined value is the acceleration in the left and right directions, it is determined whether the vehicle body corresponds to the yaw direction or the roll direction resonance. do. If NO in this step S7, the duration of the acceleration signal is measured in step S9, and the damping force, the spring constant, and the torsional force of the stabilizer are maintained in the medium, that is, medium ("MED"). It is determined whether the condition is satisfied, i.e., whether the acceleration above the first predetermined value lower than the second predetermined value continues for a predetermined time or more, and in case of YES, the process proceeds to step S10 in which the damping force or other parameter is re-added. It is set to medium ("MED") which is a predetermined level, and a medium holding timer is newly set.

If NO in step S9, the process proceeds to the next step without changing the current state. In the above embodiment, the determination of step S4 is equal to or greater than the predetermined third duration and is equal to or greater than the magnitude of the predetermined acceleration, which is effective in removing the impact of sunlight, such as noise, It goes without saying that the effect of the invention can be enhanced.

Next, another embodiment of the control device of the suspension or stabilizer of the present invention will be described with reference to the drawings. The configuration of this embodiment is almost the same as that of FIGS. 1 to 3, and description of overlapping portions is omitted.

In FIG. 1, the acceleration detecting means 2 detects the acceleration of either one of the upper, lower, left and right sides of the vehicle body 1, and the spring constant changing means 5 is, for example, Japanese Patent Laid-Open No. 63-25119. It is disclosed by Unexamined-Japanese-Patent No. 63-28709.

The controller 7 determines the magnitude of the differential value of the acceleration and the low speed time more than the predetermined level of the acceleration, respectively, and the damping force or the spring constant or the torsional force of the stabilizer is desired in accordance with the magnitude of the differential value of the acceleration. It is configured to output a command to change the value to a value to be changed, and then change the damping force and the like according to the duration.

Next, the processing procedure of the control apparatus 7 is demonstrated according to the flowchart of FIG. First, in step S1, the signal of the up-down acceleration sensor 2 is read out, and in step S2, the derivative value of the magnitude of acceleration in the up-down or left-right direction on the basis of the desired reference point (± OG) of this signal. That is, the amount of change per unit time is determined respectively.

In step S3, the duration of the acceleration above the desired value is determined by, for example, a timer. On the basis of the determination result of step S2, if it is determined in step S4 that a derivative value of acceleration equal to or greater than the first predetermined value has occurred (YES), the damping force of the suspension, the spring constant, or the torsion of the stabilizer is determined in step S5. The force is set to a medium value ("MED"), that is, a first predetermined level, and at the same time, a timer for maintaining this state is set to a predetermined time to start counting.

If the derivative value of the acceleration has not been generated at step S4, and it is determined as "NO", the process proceeds to the bypassing step S6. At this step S6, the damping force and the like are already raised to increase the MED or HARD. It is judged whether or not the timer held by MED and HARD is in operation. If NO, in step S11, one of the damping force, the spring unit, and the torsional force of the stabilizer is soft (SOFT). Ie return to the default soft state.

If the damping force is increased and maintained at step S6, that is, if the holding time of the MED or HARD remains, the process proceeds to step S7 where the current state of the medium ("MED") of one predetermined level is hard ("HARD"). It is determined whether or not the height is satisfied with "). In other words, it is determined whether the acceleration of the second predetermined value or more continues for a predetermined time.

As a result of this determination, if the duration of the acceleration above YES, that is, the second predetermined value is the vertical acceleration, for example, if the vehicle body 1 is near the half cycle of the vibration of the spring upper resonance, the present first predetermined step is determined in step S8. The level changes the state of medium ("MED") to hard ("HARD"), which is the second predetermined level, sets a hard holding timer at a predetermined time to start counting.

If the result of determination in step S7 is acceleration of right and left, it is determined that the half cycle of the yaw direction or roll direction resonance of the vehicle body 1 is performed.

If " NO " in step S7, the duration of the acceleration signal is measured and terminated in step S9. Any of damping force, spring constant, and stabilizing force of the stabilizer in the middle (medium) " MED " It is determined whether the condition for maintaining the condition is satisfied, that is, whether the acceleration of the first predetermined value lower than the second predetermined value has been continued for a predetermined time or more. If YES, the process proceeds to step S10 where the damping force or other The parameter is set back to the first predetermined level medium ("MED") and a new MED maintenance timer is set.

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

In the above embodiment, if the determination of step S4 is equal to or greater than the predetermined differential value and equal to or greater than the magnitude of the predetermined acceleration, the transient shock such as noise can be further eliminated. It goes without saying that the effect can be enhanced.

In the embodiment of the present invention, the characteristics of the suspension or the stabilizer have been described by the two-stage control, but needless to say that the same effect can be expected even with a larger number of stages. Although the case of one acceleration sensor was demonstrated, also in both cases and also when it is attached to each wheel, what is necessary is just to control the characteristic of the suspension or stabilizer corresponding to the detected acceleration sensor in the same way.

In addition, although demonstrated centering on the up-down acceleration sensor, even if it demonstrates switching to the left-right acceleration sensor, it cannot be overemphasized that the same effect is acquired in control of a rolling and a stabilizer.

As described above, according to the present invention, when it is determined by the control device that the magnitude of the acceleration or the differential value of the vehicle body in the vertical direction or the horizontal direction is equal to or greater than a predetermined level, the damping force of the suspension, the spring constant, or the torsional force of the stabilizer is determined. Either increase it (hard), increase it, or continue to change it according to the duration of a certain level above its own acceleration, then control to return to medium or basic soft state. As a device, it is simple in structure, and even when a large projection is exceeded, shock and unnecessary vibration of the vehicle body caused by the delayed operation of control can be suppressed by eliminating the delayed operation, and weakening of the riding comfort caused by misjudgement. There is an effect that can provide a suspension control device that can suppress the in the shortest time.

Claims (2)

Acceleration detection means for detecting at least one of the up and down or left and right acceleration of the vehicle body: Variable means for varying the suspension characteristic of the suspension of the vehicle spring constant or damping force or the torsional force of the stabilizer in at least three steps: When the acceleration is greater than or equal to the first predetermined value, the suspension characteristic is increased to a first predetermined level. When the acceleration becomes a second predetermined value greater than or equal to the first predetermined value, and the second predetermined value continues for a predetermined time or more, the suspension characteristic is recalled. If the acceleration is higher than the first predetermined level and the acceleration more than the acceleration to maintain this suspension characteristic at this first predetermined level while the suspension characteristic is maintained at the first predetermined level or more continues, Comprising control means for switching the variable means so that the suspension characteristic is newly set to the first predetermined level Suspension control device characterized in that. Acceleration detection means for detecting at least one of the acceleration in the vertical direction and the left and right directions of the vehicle body, comprising: means for detecting a derivative value of the acceleration; Variable means for varying the suspension characteristic such as spring constant or damping force of the suspension of the vehicle or torsional force of the stabilizer by at least three levels; When the derivative value of the acceleration is equal to or greater than a first predetermined value, the suspension characteristic is increased to a first predetermined level, and when the acceleration becomes a second predetermined value equal to or greater than the first predetermined value, and the second predetermined value continues for a predetermined time or more, The suspension characteristic is raised to a second predetermined level higher than the first predetermined level, and while the suspension characteristic is maintained at the first predetermined level or more, the suspension characteristic is continued for a predetermined time longer than the acceleration to be maintained at this first predetermined level. And a control means for switching said variable means so as to make said suspension characteristic a new first predetermined level.

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