JP2003104023A - Suspension control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a control effect from being deteriorated due to insufficiency of damping force in the next stroke of a buffer by stored energizing force of a spring, in a suspension control device having a damping characteristic adjusting type hydraulic buffer. SOLUTION: In an extension side damping characteristic control after the spring is once contracted, damping force to be generated on the extension side is controlled to be larger than target damping force. In a contraction side damping characteristic control after the spring is once extended, damping force to be generated on the contraction side is controlled to be larger than target damping force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension control device used in a vehicle.

[0002]

2. Description of the Related Art As an example of a conventional suspension control device, there is a device disclosed in Japanese Patent Laid-Open No. 2001-12530. This suspension control device includes a spring interposed between a vehicle body and a wheel, and a damping characteristic adjusting hydraulic shock absorber (shocker), and the shock absorbing means includes a damping characteristic adjusting means including a proportional solenoid in a piston rod portion. It is a so-called built-in actuator type. In the shock absorber, the damping force generated by the current supplied to the proportional solenoid is a soft (S / S) region on both the expansion side and the contraction side, and the expansion side is soft and the contraction side can be adjusted from soft to hard (S / S). H) has a characteristic region and a stretch side can be adjusted from soft to hard and has a shrink side soft (H / S) characteristic region, so that it has a stretch / shrink reversal characteristic. The suspension control device has control means for controlling the damping characteristic adjusting means so as to switch the above-mentioned S / S, S / H, and H / S characteristics of the shock absorber, and the shock absorber expands and contracts. Due to the compression / reversal characteristic, semi-active suspension control based on the so-called skyhook theory can be performed well.

In a conventional suspension control device of this kind, in an automobile, when the vehicle body is moving upward, the damping force on the extension side is controlled to a value corresponding to the upward speed of the vehicle body, and the vehicle body is moving downward. When the vehicle is moving, the contraction side damping force is controlled to a value according to the downward speed of the vehicle body. That is, the damping force is controlled according to the state of the vehicle body at that time.

Further, in a railroad vehicle, at least a pair of biasing springs for biasing the vehicle body in the left-right direction with respect to the wheel side with respect to the lateral vibration between the vehicle body and the wheels (bogie), and the left-right direction. The damping force adjustment type hydraulic shock absorber (shock absorber) installed in the direction of the vehicle cooperates with the damping force on the extension side of the shock absorber to the left and right of the vehicle body when the vehicle body is moving in one direction to the left and right with respect to the wheel side. When the vehicle body is moving to the other direction, the damping force on the contraction side of the shock absorber is controlled to a value according to the vehicle body's other direction. ing. That is, the rolling of the vehicle body is controlled according to the speed of the vehicle body in the left-right direction.

[0005]

By the way, in such a conventional suspension control device, control is performed according to the vertical or horizontal speed of the vehicle body at that time, and the past state is not taken into consideration. Therefore, when the shock absorber strokes toward the contraction side and the spring moves in the extension direction from the state where the spring accumulates the biasing force toward the extension side, the accumulated biasing force of the spring causes a large speed on the extension side of the shock absorber. However, in the conventional control, the damping force does not increase until the speed actually occurs, and as a result, a large vehicle body vibration occurs. In particular, if the stroke on the contraction side of the shock absorber becomes too large, the spring that cooperates with the shock absorber also contracts greatly and a large biasing force is accumulated, and then the biasing force is released during the stroke on the extension side of the shock absorber. As a result, the urging force affects the extension side damping force set by the damping characteristic adjusting means against the required extension side damping force, and the control effect deteriorates, resulting in poor riding comfort. There was a problem.

Similarly, when the shock absorber strokes toward the extension side, a negative biasing force is generated in the spring with reference to the biasing force in the initial state of the spring (the assembled spring is statically balanced). However, if the stroke on the extension side of the shock absorber becomes too large, the negative biasing force of the spring (hereinafter, in some cases, the positive biasing force of the spring and the negative biasing force will be combined and referred to as the spring biasing force) will increase, Due to this urging force, the shrinking side damping force set by the damping characteristic adjusting means tends to be insufficient with respect to the shrinking side damping force required for the next shrinking side stroke of the shock absorber, and the control effect deteriorates. There was a problem that the riding comfort became poor.

Then, in order to prevent the deterioration of these control effects, if the expansion side or contraction side damping force is set to be always larger than usual, as described above, the shock absorber contracts once before the expansion side stroke. When shifting, or when expanding and then moving to the contracting stroke, appropriate damping characteristic control is performed, but when the shock absorber expands without expanding once or when the shock absorber expands to the contracting stroke without expanding once. In this case, the damping characteristic control becomes excessive because there is no influence of the spring biasing force.
After all, there was a problem that the riding comfort deteriorates.

The present invention has been made in view of the above circumstances, and provides a suspension control device capable of optimizing the damping characteristic adjustment depending on the presence or absence of the influence of the biasing force of the spring. The purpose is to provide.

[0009]

According to a first aspect of the present invention, there is provided a suspension control device, which is provided so as to act on a vertical movement between a vehicle body and a wheel of a vehicle, and at least damps an extension stroke. A damping characteristic adjustment type hydraulic shock absorber having damping characteristic adjusting means capable of adjusting characteristics, a spring interposed between the vehicle body and the wheels for suspending the vehicle body with respect to the wheels, and an absolute vertical speed of the vehicle body The vehicle body speed estimating means for estimating and the damping characteristic adjusting means for increasing the damping force in the extension stroke in accordance with the upward speed when the vehicle body speed estimating means estimates that the vehicle body has an upward speed. Control means for outputting a control signal for controlling, and further, in the case where the value relating to the downward speed of the vehicle body exceeds a predetermined region, the control means is provided with an extension when the vehicle body has an upward speed next time. Characterized by comprising a correction means for correcting the control signal to the damping force of the stroke higher than that in the normal control.

With this configuration, in the damping characteristic control of the extension stroke of the shock absorber in the state where the vehicle body has the downward speed and the spring stores a large biasing force to the extension side of the shock absorber, Optimal control can be achieved by canceling out the influence of the biasing force of the spring.

The invention according to claim 2 is a suspension control device, which is provided so as to act on a vertical movement between a vehicle body and a wheel of a vehicle, and at least a damping characteristic of a compression stroke can be adjusted. Characteristic damping type hydraulic shock absorber having various damping characteristic adjusting means, a spring interposed between the vehicle body and the wheels for suspending the vehicle body with respect to the wheel, and a vehicle body speed for estimating an absolute vertical velocity of the vehicle body And a control signal for controlling the damping characteristic adjusting means so that when the vehicle body speed estimating means estimates that the vehicle body has a downward speed, the damping force in the contraction stroke increases in accordance with the downward speed. When the value relating to the upward speed of the vehicle body exceeds a predetermined range, the control means outputs a reduction stroke when the vehicle body next has a downward speed. Characterized by comprising a correction means for correcting the control signal so as to force the higher than that in the normal control.

According to this structure, the vehicle body has an upward velocity and the spring has a large negative biasing force to the contracting side of the shock absorber. In the characteristic control, it is possible to cancel the influence of the biasing force and achieve optimum control.

Further, the invention according to claim 3 is a suspension control device, which is provided so as to act on a lateral movement between a vehicle body and a wheel of a vehicle, and the suspension controller controls the left and right sides of the vehicle body on the basis of the wheel side. A damping characteristic adjusting hydraulic shock absorber having damping characteristic adjusting means which is provided so as to extend with respect to a movement in a direction and contract with a movement in another direction, and the vehicle body and wheels. And at least a pair of biasing springs that are interposed between the vehicle body and the vehicle body in the left-right direction with respect to the wheel side, a vehicle-body speed estimating unit that estimates an absolute speed of the vehicle body in the left-right direction, and the vehicle body speed. When the estimating means estimates that the vehicle body has a speed in one of the left and right directions, the damping force in the extension stroke increases in accordance with the speed in the one left and right direction, and the vehicle body speed estimating means determines the vehicle body speed. Left and right When it is estimated to have a speed, the control means for outputting a control signal for controlling the damping characteristic adjusting means, so that the damping force in the contraction stroke is increased in accordance with the speed in the other left and right directions, and Furthermore, when the value relating to the speed of the vehicle body in one of the left and right directions exceeds a predetermined region, the control means controls the damping force of the contraction stroke when the vehicle body moves in the other direction of the left, right direction, as compared with the normal control. When the control signal is corrected so as to increase the value, and the value relating to the speed of the vehicle body in the other direction in the left and right exceeds a predetermined region, the damping force of the extension stroke when the vehicle body moves in the next direction is set to the normal value. It is characterized in that a correction means for correcting the control signal is provided so as to be higher than that during control.

According to this structure, when a large biasing force to the contracting or expanding side of the shock absorber is stored in any one of the paired springs in the expansion or contraction stroke of the shock absorber, In the damping characteristic control of the contraction or extension stroke, the influence of the biasing force of the spring can be canceled to achieve the optimum control.

The invention described in claim 4 is the same as that of claim 1.
In the structure described in any one of 3 to 3, the value related to the speed of the correction means is an integral value of the speed.

With such a configuration, stable control can be performed because correction can be performed according to the tendency of speed change above a certain level without being influenced by instantaneous speed change.

The invention described in claim 5 is the same as claim 1.
In the configuration described in any of (1) to (3), the value related to the speed of the correction means is an absolute value of speed.

With this configuration, the correction can be performed by using the absolute value of the speed itself detected by the vehicle speed detecting means, so that the structure can be simplified as compared with the case of using the integrated value of the speed. .

The invention according to claim 6 is the same as claim 1.
In the configuration described in any one of 5 to 5, the correction unit corrects the control signal so as to increase the damping force by increasing the gain of the control signal.

With this configuration, since the correction can be performed only by changing the gain, the correction can be performed by a simple calculation.

The invention described in claim 7 is the same as claim 1.
In the configuration described in any one of 5 to 5, the correction means corrects the control signal by adding a constant to the control signal so as to increase the damping force as compared with the normal control.

With this configuration, since the correction can be made only by adding the constants, the correction can be made by a simple calculation.

The invention described in claim 8 is the same as claim 1.
In the structure described in any one of 5 to 5, the correction means has a control map for limiting the minimum damping force, and by comparing the control signal with the control map and selecting a corresponding correction value, a normal control is performed. Also, the control signal is corrected so as to increase the damping force.

With this configuration, it is possible to perform highly accurate correction according to the situation.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a suspension control device according to the present invention will be described below with reference to FIGS.

In FIG. 1, a compression spring 3 and a damping characteristic can be adjusted between a vehicle body 1 and four wheels 2 (only one is shown in FIG. 1 for convenience) constituting an automobile (vehicle). The four damping characteristic adjustable hydraulic shock absorbers 4 (shockers) having the expansion / contraction reversal characteristics are interposed in parallel, and these support the vehicle body 1. It should be noted that the shock absorber 4 and the spring 3 are provided for each of the four wheels 2, one for each of the four wheels 2, for a total of four, but only one of them is shown for convenience.

An acceleration sensor 6 for detecting the vertical acceleration of the vehicle body 1 is attached to the vehicle body 1. The acceleration sensor 6 supplies the detected acceleration as an acceleration signal a to the controller 7 (control means).

The controller 7 estimates the vertical absolute velocity in the absolute coordinate system of the vehicle body from the acceleration signal a supplied from the acceleration sensor 6. That is, the acceleration sensor 6 and the controller 7 form a vehicle body speed estimation means. Then, the controller 7 calculates a target damping force from the absolute speed and outputs a control current b (control signal) for controlling the actuator 5 (damping characteristic adjusting means) of the shock absorber 4 according to the target damping force.

The shock absorber 4 is, for example, a double cylinder type having a reservoir between the inner cylinder and the outer cylinder, and the inside of the inner cylinder communicates with the reservoir through a base valve provided at the bottom of the inner cylinder. Therefore, the actuator 5 is of a so-called built-in actuator type in which the actuator 5 capable of adjusting the damping characteristics on the expansion side and the contraction side according to the control current b from the controller 7 is built in the piston rod portion. The shock absorber 4 may be of a so-called actuator lateral type in which the actuator 5 is provided on the outer peripheral side of the outer cylinder, or may be a single cylinder type without a base valve. Here, the actuator 5 energizes the built-in proportional solenoid with a control current b, and drives the proportional solenoid according to the magnitude of the control current b. However, the actuator 5 is not limited to this, and may be, for example, one using a step motor or the like, and any actuator may be used as long as the drive amount changes depending on the magnitude of the control current b.

The controller 7 changes the damping characteristic of the shock absorber 4 from S / S at the initial position to S / S according to the absolute speed.
A control current b is output to the actuator 5 so as to switch to H or H / S.

At this time, the controller 7 is set so that the damping characteristic of the shock absorber 4 is S / S when the vertical absolute velocity of the vehicle body is equal to or lower than a predetermined value, and when the vehicle body exceeds the predetermined value, the vehicle body When the vehicle is moving downward, the actuator 5 is controlled (compression side control) so as to switch to the S / H side according to the speed, and when the predetermined value is exceeded, the vehicle body is moving upward. At this time, the actuator 5 is controlled (extension side control) to switch to the H / S side according to the speed, and the damping characteristics of both the extension side and the contraction side of the shock absorber 4 are controlled.

The sensor 8 is a vehicle speed sensor, a steering wheel angle sensor or the like, and outputs a signal of information such as vehicle speed and steering wheel angle to the controller 7.

Next, the contents of the arithmetic processing of the controller 7 of the suspension controller of the present embodiment will be described.

When the engine of the vehicle is started (operated) and the power source is connected to the controller 7 as shown in the main routine (FIG. 2), the controller 7 performs initialization (step S1).

Thereafter, it is determined whether a predetermined control cycle has passed (YES or NO) (step S2). If NO is determined in step S2, the process returns to step S2, and it is determined again whether or not a predetermined control cycle has elapsed. If YES is determined in step S2, the latest calculated control current b is output to the actuator 5 to drive the actuator 5 (step S3).

Following step S3, the actuator 5
Output is performed to other members and parts (LED, etc.) (step S4).

In the next step S5, an acceleration signal a is input from the acceleration sensor 6 and signals such as vehicle speed and steering wheel angle are input from the sensor 8.

Next, in step S6, the absolute velocity estimated from the acceleration signal a is multiplied by a gain (coefficient) to generate the required damping force on the extension side or the contraction side and the control required to generate the damping force. Find the current b.

Further, in this step S6, it is also determined whether or not the gain for calculating the control current b for controlling the extension side damping characteristic is made larger than that for the normal control. A subroutine for this determination is shown in FIG.

First, in step S7, in the previous stroke of the vertical vibration cycle of the vehicle body 1, it is determined whether or not the vehicle body 1 has a downward absolute vertical velocity and the value exceeds a predetermined value. It is determined whether or not the scene is where the contraction-side damping characteristic is controlled (YES or NO).

In this step S7, the stroke of the vertical vibration cycle of the vehicle body 1 means, as shown in FIG. 5, from the time point when the absolute vertical speed of the vehicle body 1 goes downward to the time point when it changes upward or upward. One stroke is from the time when it changes to the time when it changes downward. That is, FIG.
In other words, when the stroke of the vertical vibration cycle of the vehicle body 1 is in the state of, in the previous stroke, the vehicle body 1 has a downward absolute vertical velocity and the value exceeds the predetermined value. Was determined (that is, YES).

If YES is determined in step S7, it is determined in step S8 whether or not the vehicle body 1 has an upward vertical absolute velocity in the current stroke of the vertical vibration cycle of the vehicle body 1 (YES or NO). Is determined based on the calculation result of step S6. That is, referring to FIG. 5, when the current stroke of the vertical vibration cycle of the vehicle body 1 is, it is determined to be YES.

If YES is determined in the step S8, a flag for increasing the gain of the control current b (large gain flag) is set in a step S9, and the process returns to the main routine (FIG. 2).

If NO in step S8, the large gain flag is cleared in step S10, and the process returns to the main routine (FIG. 2).

If NO is determined in step S7, the large gain flag is cleared in step S10, and the process returns to the main routine (FIG. 2).

Next, the operation of the suspension control device of the present embodiment configured as described above will be described.

The previous stroke of the vertical vibration cycle of the vehicle body 1 is a scene in which the compression side damping characteristic of the shock absorber 4 is controlled. In the current stroke of the vertical vibration cycle of the vehicle body 1, the vertical absolute speed of the vehicle body 1 in the upward direction is increased. 5 is determined (ie, when a large biasing force is stored in the spring), the controller 7 generates the extension side damping force required according to the absolute speed. Since the gain is made large when the control current b necessary for this is obtained, the influence of releasing the urging force of the spring 3 which has been greatly reduced is canceled out, and the extension side damping characteristic adjustment can be optimized. .

In other cases (that is, when a large biasing force is not accumulated in the spring), the controller 7
Does not increase the gain when obtaining the control current b required to generate the extension-side damping force required according to the absolute speed (that is, performs normal control), the control becomes excessive. It is possible to optimize the expansion side damping characteristic adjustment.

As described above, in the suspension control device of this embodiment, in controlling the damping characteristic on the extension side, when the control current b for adjusting the damping characteristic is obtained according to the influence of the biasing force of the spring 3. Since the gain is changed, appropriate damping characteristic adjustment on the extension side can always be realized regardless of the influence of the biasing force of the spring 3.

In this embodiment, in the previous stroke of the vertical vibration cycle of the vehicle body 1, the spring is determined depending on whether the vehicle body 1 has a downward vertical absolute velocity and the value exceeds a predetermined value. It is determined whether or not 3 is greatly reduced, but the present invention is not limited to this. For example, the vehicle body 1 has a downward vertical absolute velocity, and the integrated value of the downward vertical absolute velocity is a predetermined value. If it exceeds, it may be determined that the spring 3 is greatly contracted and the control may be performed.

Further, in the suspension controller of the present embodiment, the magnitude of the extension side damping force is changed by changing the gain of the control current b. However, the present invention is not limited to this. A control map for limiting the minimum damping force may be provided in advance, and the optimum minimum damping force may be selected according to the influence of the biasing force of the spring 3 during the expansion side damping characteristic control of the shock absorber. Other methods may be used as long as the damping characteristics are adjusted depending on the presence or absence of the influence of the urging force of the spring 3 in the extension stroke.

Further, in the present embodiment, the flag for increasing the gain is set when YES in step S7 and YES in step S8. If the controller 7 can separately set the gain of the extension side damping characteristic and the gain of the contraction side damping characteristic by using a shock absorber capable of independently adjusting the characteristic and the damping side damping characteristic, step S8 Alternatively, the flag for increasing the gain may be set immediately when YES is determined in step S7.

Next, a second embodiment of the suspension control device according to the present invention will be described.

In the above-described first embodiment, the shock absorber 4
In order to reduce the influence of the urging force of the spring 3 accumulated on the extension side of the compression stroke, the damping characteristic on the extension side is corrected. However, in the present embodiment, the spring accumulated in the extension stroke of the shock absorber is corrected. The main difference is that the damping characteristic of the shock absorber on the contraction side is corrected in order to reduce the influence of the urging force on the contraction side. Note that the configuration of the second embodiment is almost the same as that of the first embodiment shown in FIG. 1, and only the arithmetic processing content of the controller is different. Therefore, the same components are designated by the same reference numerals. The description of the configuration is omitted, and only the arithmetic processing contents of the controller will be described.

When the engine of the vehicle is started (operated) and the power source is connected to the controller 7 as shown in the main routine (FIG. 2), the controller 7 performs initialization (step S1).

Thereafter, it is determined whether a predetermined control cycle has passed (YES or NO) (step S2). If NO is determined in step S2, the process returns to step S2, and it is determined again whether or not a predetermined control cycle has elapsed. If YES is determined in step S2, the latest calculated control current b is output to the actuator 5 to drive the actuator 5 (step S3).

Following step S3, the actuator 5
Output is performed to other members and parts (LED, etc.) (step S4).

In the next step S5, the acceleration sensor 6 receives the acceleration signal a, and the sensor 8 receives signals such as the vehicle speed and the steering wheel angle.

Next, in step S6, the absolute velocity estimated from the acceleration signal a is multiplied by a gain (coefficient) to generate the required damping force on the extension side or the contraction side and the control required to generate the damping force. Find the current b.

In step S6, it is also determined whether or not the gain for calculating the control current b for controlling the compression-side damping characteristic is set to be larger than that for normal control. A subroutine for this determination is shown in FIG.

First, in step S7a, in the previous stroke of the vertical vibration cycle of the vehicle body 1, it is determined whether or not the vehicle body 1 has a downward absolute vertical velocity and the value exceeds a predetermined value. It is determined whether or not it is a scene in which the extension side damping characteristic is controlled (YES or NO).

In this step 7a, the stroke of the vertical vibration cycle of the vehicle body 1 means, as shown in FIG. 5, from the time point when the absolute vertical speed of the vehicle body 1 goes downward to the time point when it changes upward or upward. One stroke is from the time when it changes to the time when it changes downward. That is, FIG.
In other words, when the stroke of the vertical vibration cycle of the vehicle body 1 is in the state of, in the previous stroke, the vehicle body 1 has an upward vertical absolute velocity, and the value exceeds the predetermined value. Was determined (YES).

If YES is determined in the step S7a,
In step S8a, it is determined based on the calculation result of step S6 whether or not the vehicle body 1 has the downward vertical absolute velocity in the current stroke of the vertical vibration cycle of the vehicle body 1. That is, referring to FIG. 5, the vehicle body 1
If the current stroke of the vertical vibration cycle of is
It is determined to be S.

If YES is determined in step S8a,
Next, in step S9a, a flag for increasing the gain of the control current b (large gain flag) is set, and the process returns to the main routine (FIG. 2).

If NO in step S8a, the large gain flag is cleared in step S10a, and the process returns to the main routine (FIG. 2).

If NO is determined in step S7a, the large gain flag is cleared in step S10a, and the process returns to the main routine (FIG. 2).

Next, the operation of the suspension control device of the present embodiment configured as described above will be described.

The previous stroke of the vertical vibration cycle of the vehicle body 1 is a scene in which the expansion side damping characteristic of the shock absorber 4 is controlled. In the current stroke of the vertical vibration cycle of the vehicle body 1, the vertical absolute speed of the vehicle body 1 in the downward direction is lowered. 5 (that is, when a large negative biasing force is accumulated in the spring), the controller 7 determines that the contraction-side damping force required according to the absolute speed. Since the gain is made large when the control current b required to generate the torque is generated, the effect of releasing the large biasing force of the spring 3 to the compression side is canceled out, and the compression side damping characteristic adjustment is optimized. can do.

In other cases (that is, when a large biasing force is not accumulated in the spring), the controller 7
Does not make the gain large (that is, performs normal control) when obtaining the control current b required to generate the contraction-side damping force required according to the absolute speed, so control is excessive. Therefore, it is possible to optimize the contraction-side damping characteristic adjustment.

As described above, in the suspension control device of the present embodiment, when controlling the damping characteristic on the compression side, when the control current b for adjusting the damping characteristic is obtained according to the influence of the biasing force of the spring 3. Since the gain is changed, an appropriate damping characteristic adjustment on the contraction side can always be realized regardless of the influence of the biasing force of the spring 3.

In this embodiment, in the previous stroke of the vertical vibration cycle of the vehicle body 1, the spring is determined depending on whether the vehicle body 1 has an upward absolute vertical velocity and the value exceeds a predetermined value. It is determined whether 3 is greatly extended from the initial position, but it is not limited to this,
For example, when the vehicle body 1 has an upward vertical absolute velocity and the integrated value of the upward vertical absolute velocity exceeds a predetermined value, it may be determined that the spring 3 is greatly extended and control is performed. .

Further, in the suspension controller of the present embodiment, the magnitude of the extension side damping force is changed by changing the gain of the control current b, but the present invention is not limited to this, and, for example, on the contraction side. A control map for limiting the minimum damping force may be provided in advance, and the optimum minimum damping force may be selected according to the influence of the biasing force of the spring 3 during the compression side damping characteristic control of the shock absorber. Other methods may be used as long as the damping characteristics are adjusted depending on the presence or absence of the influence of the urging force of the spring 3 in the contraction stroke.

Further, in the present embodiment, the flag for increasing the gain is set when YES in step S7a and YES in step S8a. When the controller 7 can separately set the gain of the extension side damping characteristic and the gain of the contraction side damping characteristic by using a shock absorber capable of independently adjusting the characteristic and the contraction side damping characteristic, step S
The determination of 8a may be omitted, and the flag for increasing the gain may be set immediately when YES is determined in step S7a.

Next, a third embodiment of the suspension control device according to the present invention will be described.

The configuration of the suspension control device according to the present embodiment is substantially the same as that of the suspension control device according to the first embodiment shown in FIG. 1, but the damping characteristic of the shock absorber 4 is variable only on the extension side. The difference is that the damping characteristic on the contraction side is fixed. That is, in the suspension control device according to the present embodiment, the shock absorber 4
The attenuation characteristic of is switched between S / S and H / S, and the initial position is S / S.

In the suspension control device according to the present embodiment, the controller 7 sets the damping characteristic of the shock absorber 4 to the S / S at the initial position according to the vertical absolute velocity of the vehicle body estimated from the acceleration signal a. The control current b is output to the actuator 5 so as to switch between H and S. At this time, the controller 7 is set so that the damping characteristic of the shock absorber 4 is S / S when the vertical absolute velocity of the vehicle body is less than or equal to a predetermined value, and H / S when it exceeds the predetermined value.
The actuator 5 is controlled to switch to.

Next, the arithmetic processing contents of the controller 7 of the suspension controller of the present embodiment will be described. The arithmetic processing contents of the controller 7 of the suspension control device of the present embodiment are the arithmetic processing contents of the controller 7 of the suspension control device of the first embodiment shown in FIG. 2 except that the damping characteristic is variable only on the extension side. However, the subroutine in step S6 is different. Therefore, only the subroutine will be described with reference to FIG.

First, in step S7b, it is determined whether or not the vehicle body 1 has a downward absolute vertical velocity in the current stroke of the vertical vibration cycle of the vehicle body 1 and the value exceeds a predetermined value (YES or NO). To be judged.

If YES is determined in step S7b,
In step S9b, the control current is calculated by adding the constant c to the control current b determined in step S6 of FIG. 2, and the process returns to the main routine (FIG. 2).

If NO is determined in step S7b, the control current b determined in step S6 of FIG. 2 is directly used as the control current in step S10b, and the process returns to the main routine (FIG. 2).

In the suspension controller of the present embodiment, the damping characteristics of expansion / contraction change between S / S and H / S. That is, even if the damping characteristic on the extension side is changed, the damping characteristic on the contraction side is soft and fixed. Therefore, in the current stroke of the vertical vibration cycle of the vehicle body 1, the vehicle body 1 has a downward absolute vertical velocity. Even if the control for changing the damping characteristic on the extension side is performed, there is no effect on the damping force on the contraction side that is actually generated by the shock absorber 4 at that time. Therefore, in the suspension control device of the present embodiment, the extension-side damping characteristic can be controlled based on the determination of the current stroke of the vertical vibration cycle of the vehicle body 1. Therefore, whether the current stroke of step S8 in FIG. Whether or not the extension side damping characteristic is adjusted depending on the presence or absence of the biasing force of the spring 3 is obtained by the arithmetic processing content which is simpler than that of the suspension control device of the first embodiment. Attenuation characteristic adjustment on the extension side can be realized.

In the suspension control device of the present embodiment, the extension side damping characteristic is adjusted depending on whether or not the biasing force of the spring 3 affects the control current b. However, the present invention is not limited to this, and the magnitude of the extension side damping force may be changed by changing the gain when calculating the control current b as in the suspension control device of the first embodiment. Further, a control map for limiting the minimum damping force on the extension side is provided in advance, and the optimum minimum damping force is selected according to the presence or absence of the influence of the biasing force of the spring 3 during the extension side damping characteristic control of the shock absorber. Alternatively, if the damping characteristic is adjusted depending on the presence or absence of the influence of the biasing force of the spring 3 in the extension stroke,
Other methods may be used.

Next, a fourth embodiment of the suspension control device according to the present invention will be described with reference to FIGS. 7 and 8.

In this embodiment, the suspension control device according to the present invention is applied to a railway vehicle. In FIG. 7, a vehicle body is provided between a vehicle body 31 and a bogie 32 which constitute the railway vehicle 30 (vehicle). A leftward biasing spring 33a for biasing leftward and a rightward biasing spring 3 for biasing the vehicle body rightward.
3b and a damping characteristic adjustable hydraulic shock absorber 34 (shocker) having adjustable damping characteristics and having expansion / contraction reversal characteristics are interposed in parallel, and these support the vehicle body 31 in the left-right direction. . Here, as shown in FIG. 7, the shock absorber 34 contracts when the vehicle body 31 moves to the right in FIG. 7 with respect to the carriage 32, and expands when the vehicle body 31 moves to the left in FIG. 7 with respect to the carriage 32. Thus, it is interposed between the vehicle body 31 and the truck 32. In this embodiment, the shock absorber 34 is
It is a so-called single rod type in which the rod projects only from one end side of the outer cylinder, but it is not limited to this.
A so-called double rod type in which rods protrude from both ends of the outer cylinder may be used. In this case, the expansion and contraction of the shock absorber is based on the expansion and contraction of either one of the rods from the outer cylinder.

An acceleration sensor 36 for detecting the lateral acceleration of the vehicle body 31 is attached to the vehicle body 31.
The acceleration sensor 36 supplies the detected acceleration as an acceleration signal a to the controller 37 (control means).

The controller 37 estimates the absolute speed of the vehicle body in the left-right direction from the acceleration signal a supplied from the acceleration sensor 36. That is, the acceleration sensor 36 and the controller 37 form a vehicle body speed estimating means. Then, the controller 37 calculates the target damping force from the absolute speed and controls the actuator 35 (damping characteristic adjusting means) of the shock absorber 34 according to the target damping force.
(Control signal) is output.

The shock absorber 34 is a so-called actuator lateral type, in which an actuator 35 capable of adjusting the damping characteristics on the expansion side and the contraction side according to the control current b from the controller 37 is provided on the outer peripheral side of the outer cylinder. There is. The shock absorber 34 may be a so-called actuator built-in type.
Here, the actuator 35 energizes the built-in proportional solenoid with the control current b, and drives the proportional solenoid according to the magnitude of the control current b. However, the actuator 35 is not limited to this, and may be, for example, a step motor or the like, and any actuator may be used as long as the drive amount changes depending on the magnitude of the control current b.

The controller 37 changes the damping characteristic of the shock absorber 34 from S / S at the initial position to S according to the absolute speed in the left-right direction of the absolute coordinate system of the vehicle body estimated from the acceleration signal a.
/ H or H / S so that the actuator 35
The control current b is output to.

At this time, the controller 37 determines that the vehicle body 31
If the absolute speed in the left-right direction of the
The damping characteristic of No. 4 is set to S / S, and when the vehicle body 31 is moving to the right side of FIG. Control of actuator 35 to switch to H side (shrink side control)
And the vehicle body 31 moves to the bogie 32 when a predetermined value is exceeded.
On the other hand, when moving to the left side of FIG. 7, the actuator 5 is controlled (extension side control) to switch to the H / S side according to the speed, and both the extension side and the contraction side of the shock absorber 34 are controlled. Controls damping characteristics.

Next, the contents of the arithmetic processing of the controller 37 of the suspension control device of the present embodiment will be described. Since the main routine is almost the same as that of the first embodiment shown in FIG. Omitting only the subroutine for determining whether to increase the gain when calculating the control current b will be described with reference to FIG.

First, in step S7c, in the previous stroke of the left-right vibration cycle of the vehicle body 31, whether the absolute speed of the vehicle body 31 in the left-right direction exceeds a predetermined value regardless of the direction, that is, in the absolute speed of the left-right direction. Value (| V |)
Exceeds a predetermined value (V ₀ ) (YES or NO
Is determined.

Here, the stroke of the left-right vibration cycle of the vehicle body 31 is the same as the vertical vibration cycle shown in FIG.
One stroke is defined as the time from when the absolute velocity in the left-right direction of 1 changes to the left to the time of changing to the right, or from the time of changing to the right to the time of changing to the left.

If YES is determined in the step S7c,
Next, in step S8c, it is determined whether or not the present time has changed from the previous stroke to the current stroke.

If YES is determined in step S8c,
Next, in step S9c, a flag for increasing the gain of the control current b (large gain flag) is set, and the subroutine ends.

If NO is determined in the step S8c, the large gain flag of the control current b is cleared in a step S10c, and the subroutine ends.

If NO is determined in the step S7c, the large gain flag of the control current b is cleared in the step S10c, and the subroutine ends.

Next, the operation of the suspension control device of the present embodiment configured as described above will be described.

When the vehicle body 31 moves largely to the right or left with respect to the carriage 32 in the previous stroke of the left-right vibration cycle of the vehicle body 31, the leftward biasing spring 33a or the rightward biasing spring 33.
Any one of b shrinks greatly and accumulates the biasing force. Then, the accumulated biasing force is released in the cycle next to the left-right vibration cycle. However, in such a case, the controller 37 increases the gain when obtaining the damping force required according to the acceleration signal a and the control current b required to generate the damping force. The effect of releasing the biasing force is canceled, and the damping characteristic adjustment can be optimized.

In the previous stroke of the left-right vibration cycle of the vehicle body 31, if the vehicle body 31 does not move much to the right or left with respect to the carriage 32, the urging force is not accumulated, but in this case,
Since the controller 37 does not make the gain large, the attenuation characteristic adjustment can be optimized without being excessive.

As described above, in the suspension control device of the present embodiment, the gain at the time of obtaining the control current b for adjusting the damping characteristic according to the influence of the biasing force of the spring 33a or the spring 33b in the extension side control. To change
Regardless of the influence of the biasing force of the spring 33a or the spring 33b, the optimum damping characteristic adjustment on the extension side can always be realized.

In the suspension control device of this embodiment, the magnitude of the extension side damping force is changed by changing the gain of the control current b, but the present invention is not limited to this. It is also possible to previously provide a control map for limiting the above, and to select an appropriate minimum damping force according to the influence of the biasing force of the spring during the damping characteristic control of the shock absorber, and to set a constant for the control current b. The extension side damping characteristic may be adjusted depending on whether or not the biasing force of the spring 3 influences, and the damping characteristic may be adjusted depending on whether or not the biasing force of the spring 3 influences. if there is,
Other methods may be used.

Further, in this embodiment, the vehicle body 31
In the previous stroke of the left-right vibration cycle of No. 1, it is determined whether the large gain flag is set or not depending on whether the absolute speed of the vehicle body 31 in the left-right direction exceeds a predetermined value.
However, the present invention is not limited to this. For example, when the integrated value of the absolute speed in the left-right direction of the vehicle body 31 exceeds a predetermined value, it may be determined whether the large gain flag is set or not to perform control.

Further, in the present embodiment, only the damping characteristic control for the vibration in the left-right direction is performed, but the first, second,
The same damping characteristic control as to the vertical vibration as in the third embodiment may be performed together.

Further, in the suspension control devices of the first to fourth embodiments, control is performed so as to uniformly increase the damping force as compared with normal control, regardless of the amount of expansion or contraction of the spring. However, the present invention is not limited to this, using a sensor that senses the amount of expansion or contraction of the spring, or estimating the amount of expansion or contraction of the spring from the magnitude of the absolute speed, or the like. The damping force may be increased in multiple stages according to the degree of contraction. The spring has different biasing forces that accumulate depending on the amount of expansion or contraction.However, if the amount of expansion or contraction of the spring is not so large, the adjustment will be too large, resulting in overcontrol. Alternatively, when the amount of expansion or contraction of the spring is maximal, it is possible to prevent insufficient adjustment and insufficient damping force, and it is possible to perform more appropriate control.

[0105]

According to the present invention, in the suspension control device, when the biasing force of the spring influences the damping characteristic control of the shock absorber, the damping force generated is increased so as to cancel the influence of the biasing force. Therefore, the optimum damping force can be generated in the damping characteristic control of the shock absorber, and the riding comfort of the vehicle can be improved.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a suspension control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing calculation contents of a controller of the suspension control device of the present invention.

FIG. 3 is a flowchart showing detailed calculation contents of step S6 in the suspension control device according to the first embodiment of the present invention among the calculation contents of FIG.

FIG. 4 is a flowchart showing detailed calculation contents of step S6 in the suspension control device according to the second embodiment of the present invention among the calculation contents of FIG.

FIG. 5 is a diagram showing a process of a vertical vibration cycle of the vehicle body 1.

FIG. 6 is a flowchart showing detailed calculation contents of step S6 in the suspension control device of the third embodiment of the present invention among the calculation contents of FIG. 2;

FIG. 7 is a diagram schematically showing a suspension control device according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart showing detailed calculation contents of step S6 in the suspension control device of the fourth exemplary embodiment of the present invention among the calculation contents of FIG. 2;

[Explanation of symbols]

1 car body Two wheels 3 springs 4 shock absorber (hydraulic shock absorber with adjustable damping characteristics) 5 Actuator (attenuation characteristic adjusting means) 6 Accelerometer 7 Controller (control means) 30 railway vehicles 31 car body 32 dolly 33a Leftward biasing spring 33b Rightward bias spring 34 Shock absorber (Attenuation characteristic adjustment type hydraulic shock absorber) 35 Actuator (attenuation characteristic adjusting means) 36 Accelerometer 37 controller (control means)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Osawa             1-6-3 Fujimi, Kawasaki-ku, Kawasaki-shi, Kanagawa             Issue Tokiko Co., Ltd. F-term (reference) 3D001 AA02 BA01 DA17 DA18 EA08                       EA22 EA34 EB32 EC02 ED02                       ED04                 3J069 AA50 EE64

Claims (8)

[Claims] 1. A damping-property adjusting hydraulic shock absorber, which is provided so as to act on vertical movement between a vehicle body and a wheel of a vehicle, and which has damping-property adjusting means capable of adjusting the damping characteristic of at least an extension stroke, A spring that is interposed between the vehicle body and the wheel to suspend the vehicle body with respect to the wheel, a vehicle body speed estimation unit that estimates the vertical absolute speed of the vehicle body, and a vehicle body speed estimation unit that controls the upward velocity of the vehicle body. If it is estimated to have, the control means for outputting a control signal for controlling the damping characteristic adjusting means so that the damping force in the extension stroke is increased according to the upward speed, and further comprising: ,
When the value relating to the downward speed of the vehicle body exceeds a predetermined region, a correction for correcting the control signal so as to increase the damping force of the extension stroke when the vehicle body has the upward speed next time as compared with the case of normal control A suspension control device comprising means. 2. A damping-property adjusting hydraulic shock absorber, which is provided so as to act on vertical movement between a vehicle body and a wheel of a vehicle, and which has damping-property adjusting means capable of adjusting the damping characteristic of at least a compression stroke, A spring interposed between the vehicle body and the wheel to suspend the vehicle body with respect to the wheel, a vehicle body speed estimating means for estimating the vertical absolute velocity of the vehicle body, and a vehicle body speed estimating means for controlling the downward speed of the vehicle body. Control means for outputting a control signal for controlling the damping characteristic adjusting means so that the damping force in the contraction stroke is increased in accordance with the downward speed when it is estimated that the control means is further provided. ,
When the value relating to the upward speed of the vehicle body exceeds a predetermined region, a correction for correcting the control signal so as to increase the damping force of the contraction stroke when the vehicle body has the downward speed next time than in the normal control A suspension control device comprising means. 3. A vehicle body is provided so as to act on a lateral movement between a vehicle body and a wheel, and the vehicle body extends in one lateral direction with respect to the wheel side and moves in another lateral direction. A damping characteristic adjustable hydraulic shock absorber that is provided so as to contract with respect to the vehicle and that has damping characteristic adjusting means capable of adjusting the damping characteristic of the expansion and contraction stroke, and is interposed between the vehicle body and the wheels, and the body side At least a pair of urging springs for urging the vehicle body, a vehicle body speed estimating means for estimating an absolute speed of the vehicle body in the lateral direction of the vehicle body, and the vehicle body speed estimating means for estimating that the vehicle body has a speed in one lateral direction. If the vehicle body speed estimating means estimates that the vehicle body has a velocity in the other direction, the left-right direction is increased. Depending on the speed in the other direction A control unit for outputting a control signal for controlling the damping characteristic adjusting unit so that the damping force in the contraction stroke becomes high, and the control unit is provided with a value relating to the speed of the vehicle body in one of the left and right directions. If it exceeds the predetermined area, the control signal is corrected so that the damping force of the contraction stroke when the vehicle body moves to the other direction in the left / right direction next becomes higher than that in the normal control, and When the value relating to the speed exceeds a predetermined region, a correction means is provided for correcting the control signal so that the damping force of the extension stroke when the vehicle body next moves in one direction is increased as compared with the normal control. Suspension control device characterized by. 4. The suspension control device according to claim 1, wherein a value related to the speed of the correction means is an integrated value of the speed. 5. The suspension control device according to claim 1, wherein a value related to the speed of the correction means is an absolute value of the speed. 6. The correction means corrects the control signal so that the damping force is increased by increasing the gain of the control signal as compared with the normal control. Suspension control device according to. 7. The correction means corrects the control signal by adding a constant to the control signal so as to increase the damping force as compared with the normal control.
6. The suspension control device described in 5 above. 8. The correction means has a control map for limiting the minimum damping force, and by comparing the control signal with the control map to select a corresponding correction value, the damping force is increased as compared with the normal control. The suspension control device according to claim 1, wherein the control signal is corrected so as to increase