JP6443316B2 - Suspension control device for vehicle - Google Patents

Description

  The present invention relates to a vehicle suspension control apparatus, and more particularly to a vehicle suspension control apparatus capable of changing a damping coefficient.

  Patent Document 1 discloses a suspension device that can appropriately change the damping coefficient of a shock absorber disposed on each wheel. In this device, the attenuation coefficient of each wheel is controlled according to various requirements. When the front wheel of the vehicle rides on the protrusion, the damping coefficient of the rear wheel is made soft until the rear wheel gets over the protrusion regardless of other control requirements (the third embodiment, FIG. 10). reference).

  According to the above control, the damping coefficient of the rear wheel is surely made soft at the stage where the rear wheel rides on the protrusion after the front wheel passes over the protrusion. For this reason, according to the apparatus of Patent Document 1, when the rear wheel gets over the protrusion over which the front wheel rides, a large impact is not transmitted to the vehicle body, and excellent riding comfort can be realized.

JP 2010-235019 A

  However, when the front wheel of the vehicle rides on the protrusion, the front part of the vehicle body is lifted upward. And if the front part of a vehicle body is lifted, the influence will cause the sinking behind a vehicle body. At this time, if the damping coefficient of the rear wheels is soft, a large pitch is likely to occur in the vehicle body. In this regard, the suspension device described in Patent Document 1 has a problem that it is easy to cause a large pitch behavior, although it is suitable for suppressing an impact caused by the protrusion.

  The present invention has been made to solve the above-described problems, and can achieve a good riding comfort while sufficiently suppressing changes in the behavior of the vehicle body when the wheels pass through the unevenness of the road surface. An object of the present invention is to provide a vehicle suspension control device.

In order to achieve the above object, the present invention is a vehicle suspension control device including a spring element and a shock absorber whose damping coefficient can be changed in each wheel of the vehicle,
A road surface input sensor for generating a signal corresponding to the vertical movement of each wheel;
A sprung behavior sensor for generating a signal corresponding to the vertical movement of the vehicle body at the position of each wheel;
An unevenness judging means for judging whether one end wheel located at one end of the vehicle is on the unevenness of the road surface based on the signal of the road surface input sensor,
Based on the signal from the sprung behavior sensor, push-up determination means for determining whether the upward acceleration of the vehicle body at the other end relative to the one end is equal to or less than a threshold value;
A first control means for setting a damping coefficient of a shock absorber located at the other end to a hard value when the one end wheel is on a road surface unevenness and the upward acceleration is equal to or less than the threshold;
The damping coefficient of the shock absorber located at the other end when the one end wheel is on the road surface unevenness and the upward acceleration is not less than or equal to the threshold value is a soft soft value compared to the hard value. A second control means;
It is characterized by providing.

  When one end wheel enters the unevenness of the road surface in the vehicle, the height of the vehicle body changes at the position of the one end wheel. As a result, downward and upward vibrations are generated at the other end of the vehicle body by the function of the spring element. According to the present invention, the shock absorber at the other end is controlled in accordance with the upward acceleration of the vehicle body at the other end until the one end wheel reaches the unevenness on the road surface and finishes passing through the protrusion. Specifically, after the wheel at one end enters the unevenness, when the upward acceleration at the other end is equal to or less than the threshold value, the attenuation coefficient at the other end is set to a hard value. As a result, the sinking of the other end is suppressed, and the change in the posture of the vehicle body is suppressed. In the process in which the upward acceleration falls below the threshold, it is difficult for the passenger to feel the push-up feeling. For this reason, the ride comfort of this process is not spoiled by making a damping coefficient into a hard value. If the upward acceleration of the other end exceeds the threshold value after the wheel of one end gets into the unevenness and finishes passing through the protrusion, the attenuation coefficient of the other end is changed to a soft value. It is easy to convey a feeling of pushing up to the vehicle occupant in a situation where upward acceleration is generated in the vehicle body. In the present invention, since the attenuation coefficient at the other end is softened under such circumstances, it is difficult for the passenger to feel the push-up feeling. For this reason, according to this invention, favorable riding comfort is realizable, fully suppressing the behavior change of the vehicle body at the time of a wheel passing a protrusion.

It is a figure which shows the structure of Embodiment 1 of this invention. FIG. 2 is a diagram illustrating a state in which the front wheel of the vehicle rides on a protrusion in the configuration illustrated in FIG. 1. It is a timing chart regarding control of a comparative example. It is a timing chart regarding control of Embodiment 1 of the present invention. It is a flowchart of a routine executed in the first embodiment of the present invention.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is a diagram for explaining the configuration of the first embodiment of the present invention. The configuration shown in FIG. 1 includes a vehicle body 10. FIG. 1 schematically shows the vehicle body 10 in a side view. Here, the left side in FIG. 1 is the front of the vehicle, and the right side is the rear of the vehicle. Moreover, the arrow shown with the code | symbol v in FIG. 1 represents that the vehicle body 10 is moving ahead with the speed v per hour.

  A laser sensor 12 is mounted on the front surface of the vehicle body 10. The laser sensor 12 is a sensor whose scanning range is the road surface in front of the vehicle body. In the present embodiment, the detection signal of the laser sensor 12 is used to detect the position and size of the unevenness present on the road surface. The laser sensor 12 can be replaced with another sensor such as an image sensor as long as it can be used for detecting unevenness on the road surface.

  A front wheel 16 is mounted in front of the vehicle body 10 via a suspension device 14. The suspension device 14 and the front wheel 16 are connected to the left and right sides of the vehicle body 10, respectively. Since these structures are substantially the same, the left and right front wheel suspension devices are collectively referred to as “suspension device 14”, and the left and right front wheels are collectively referred to as “front wheel 16”.

  The suspension device 14 for the front wheel 16 includes a spring element 18 and a shock absorber 20. Symbols Ksf and Csf shown in FIG. 1 represent the spring constant of the spring element 18 and the damping coefficient of the shock absorber 20, respectively. In the present embodiment, the shock absorber 20 can switch the damping coefficient Csf between two levels: a hard value and a soft value. However, the number of switching stages of the damping coefficient is not limited to two, and the shock absorber 20 can be replaced with one that can switch more stages.

  The suspension device 14 has an unsprung member 22 connected to the front wheel 16 via a suspension arm. An unsprung acceleration sensor 24 is attached to the unsprung member 22. The unsprung acceleration sensor 24 can detect the vertical acceleration of the unsprung part including the wheel for each of the front wheels 16. Hereinafter, the vertical acceleration has a sign that the upward direction is positive and the downward direction is negative.

  The suspension device 14 also includes a sprung member 26 connected to the vehicle body 10 side. A sprung acceleration sensor 28 is attached to the sprung member 26. The sprung acceleration sensor 28 can detect the vertical acceleration generated in the vehicle body 10 at each position of the front wheel 16. Hereinafter, the vertical acceleration also has a sign that the upward direction is positive and the downward direction is negative.

  The suspension device 14 is further equipped with a stroke sensor 30. The stroke sensor 30 can detect the stroke amount of the shock absorber 20, that is, the relative displacement of the unsprung member 22 and the sprung member 26.

  As shown in FIG. 1, a rear wheel 34 is mounted behind the vehicle body 10 via a suspension device 32. As in the case of the front wheel side, the “suspension device 32” and the “rear wheel 34” are generic names of the suspension device and the left and right rear wheels connected to the left and right of the rear of the vehicle body, respectively.

  Similar to the suspension device 14 for the front wheel 16, the suspension device 32 for the rear wheel 34 includes a spring element 36 and a shock absorber 38. Symbols Ksr and Csr shown in FIG. 1 represent their spring constant and damping coefficient, respectively. Further, as shown in FIG. 1, the unsprung acceleration sensor 40, the sprung acceleration sensor 42, and the stroke sensor 44 are also attached to the suspension device 32 of the rear wheel 34. Since these configurations and functions are substantially the same as those on the front wheel side, description thereof will be omitted here.

  The configuration shown in FIG. 1 includes an ECU (Electronic Control Unit) 50. The various sensors arranged on each wheel and the laser sensor 12 arranged on the vehicle body 10 are all electrically connected to the ECU 50.

  The ECU 50 can calculate the unsprung displacement amount Xwf and the unsprung displacement amount Xbf of the front wheel 16 by a known method based on signals supplied from these sensors. Hereinafter, those calculation methods will be exemplified.

  The unsprung displacement amount Xwf at the front wheel 16 corresponds to the integral value of the unsprung acceleration at the position of each wheel. Therefore, the ECU 50 can calculate the unsprung displacement amount Xwf by integrating the signal from the unsprung acceleration sensor 24.

  The unsprung displacement amount Xwf can also be calculated using the detection value of the laser sensor 12. In the present embodiment, the position and size of the unevenness on the road surface in front of the vehicle body can be detected by the laser sensor 12. If the position of the road surface unevenness is known, the timing at which the left front wheel reaches the unevenness, the timing to ride on, the timing to pass, etc. can be calculated based on the vehicle speed v. Then, if the result is analyzed in combination with the size of the unevenness, the unsprung displacement amount Xwf can be calculated in real time.

  The sprung displacement amount Xbf at the front wheel corresponds to the integral value of the sprung acceleration at the position of each wheel. Therefore, the ECU 50 can calculate the sprung amount Xbf by integrating the signal from the sprung acceleration sensor 28. The unsprung displacement amount Xbf also corresponds to the sum of the unsprung displacement amount Xwf and the stroke amount of the shock absorber 20. Therefore, the ECU 50 can also calculate the sprung amount Xbf based on the unsprung amount Xwf calculated by the above-described method and the signal from the stroke sensor 30.

  The ECU 50 can also calculate the unsprung displacement amount Xwr and the unsprung displacement amount Xbr based on the output values of various sensors for each of the rear wheels. Since these calculation methods are substantially the same as the calculation on the front wheel side, detailed description thereof is omitted here.

[Problem to be solved by the first embodiment]
FIG. 2 is a diagram schematically showing a state in which the front wheel 16 rides on the protrusion 52 on the road surface during traveling of the vehicle according to the present embodiment. When the front wheel 16 rides on the protrusion 52, the position of the front wheel 16 rises. As a result, the front position of the vehicle body 10 is lifted upward, as indicated by a broken line in FIG.

  FIG. 3 is a timing chart showing the change in behavior that occurs in the vehicle body 10 after the ride shown in FIG. 2 occurs in relation to the damping coefficient of the rear wheel 34. Here, the uppermost “front wheel input” column shows the waveform of the unsprung displacement amount Xwf of the front wheel 16. The column of “required rear wheel damping coefficient” in the second row shows the waveform of the required value for the damping coefficient Csr of the rear wheel 34. In this column, the broken line 54 indicates a state in which the attenuation coefficient Csr is fixed to a hard value, the alternate long and short dash line 56 indicates a state in which the attenuation coefficient Csr is fixed to a soft value, and the solid line 58 indicates an attenuation by control of the comparative example. Changes in the coefficient Csr are shown respectively.

  In FIG. 3, the column of “rear wheel sprung acceleration” in the third row shows a signal waveform of a sprung acceleration sensor 42 (see FIG. 1) arranged on the rear wheel 34. The fourth column “Pitch Acceleration” shows a waveform of pitch acceleration generated in the vehicle body 10 (acceleration toward the forward tilt side is positive and acceleration toward the rear tilt side is negative). In these columns, a broken line (hard), an alternate long and short dash line (soft), and a solid line (comparative example) correspond to the line types of the attenuation coefficient waveform shown in the second column.

  In the example shown in FIG. 3, the front wheel input increases toward the peak value from about time t1, and the front wheel input returns to almost zero at about time t3. Such front wheel input occurs when the front wheel 16 reaches the protrusion 52 at time t1 and the front wheel 16 passes through the protrusion 52 at time t3.

  When the front wheel 16 rides on the protrusion 52, the front of the vehicle body 10 is lifted, and the load on the vehicle body 10 shifts to the rear wheel side. And if the weight of the vehicle body 10 shifts to the rear, the load applied to the suspension device 32 of the rear wheel 34 increases, and a sinking behavior appears behind the vehicle body 10.

  Since the spring element 36 is incorporated in the suspension device 32, the sinking that has occurred behind the vehicle body 10 eventually converges. Then, as the spring element 36 shifts to the extension stroke, a lifting behavior is caused behind the vehicle body 10. In the third stage of FIG. 3, after the time t1, the sprung acceleration of the rear wheel 34 shows vibration as a result of the vibration on the spring starting from the above-described sinking.

  Further, a shock absorber 38 is incorporated in the suspension device 32 together with the spring element 36. For this reason, the sprung vibration of the rear wheel 34 is gradually attenuated. The reason why the amplitude of the sprung acceleration shown in FIG. 3 is gradually attenuated and toward convergence after time t3 is due to the damping effect by the shock absorber 38.

  By the way, it is desirable that the vibration of the vehicle body 10 be converged in a short time without giving a strong push-up feeling to the vehicle occupant. When the damping coefficient of the rear wheel 34 is always set to a hard value (see the broken line 54), as shown in FIG. 3, the rear wheel spring acceleration amplitude converges early, but the rear wheel 34 is pushed up. It will be easy to be transmitted to the person.

  On the other hand, if the damping coefficient of the rear wheel 34 is always set to a soft value (dashed line 56), the push-up feeling from the rear wheel 34 is difficult to be transmitted to the passenger, but as shown in FIG. A situation occurs in which the amplitude of the upper acceleration does not converge over a long period of time.

  As a technique for avoiding these inconveniences, for example, as in the comparative example indicated by the solid line 58 in FIG. 3, the damping coefficient of the rear wheel 34 is considered to be a soft value only during the period from time t1 to time t3. . According to such a method, during the period in which the front wheel 16 is forced to vibrate due to the protrusion 52, that is, during the period in which the sprung acceleration of the rear wheel 34 shows a large amplitude in FIG. Becomes a soft value, and it is possible to create a situation where it is difficult for the passenger to feel the push-up feeling. Further, according to this control, after the front wheel 16 passes through the projection 52, the vibration of the rear wheel 34 can be quickly converged with the damping coefficient of the rear wheel 34 as a hard value.

  However, according to the control of the above comparative example, the damping coefficient of the rear wheel is set to the soft value immediately after the time t1 at which the largest sinking is likely to occur on the spring of the rear wheel 34. For this reason, as shown in the final stage of FIG. 3, the pitch acceleration in the comparative example shows substantially the same amplitude as when the attenuation coefficient is always a soft value from time t1 to time t3. That is, according to the control of the comparative example, the vehicle body 10 has a large pitch behavior similar to the case where the damping coefficient is always maintained at the soft value.

[Features of Embodiment 1]
FIG. 4 is a timing chart for explaining the behavior of the vehicle body 10 accompanying the control of the present embodiment. In the present embodiment, when the front wheel 16 rides on the protrusion 52, the required damping coefficient of the rear wheel 34 is controlled as indicated by the solid line 60 in the second stage of FIG. Specifically, the required value is maintained at a hard value while the acceleration on the rear wheel spring is changed in the negative region after the riding of the front wheel 16 is detected at time t1.

  As a result, as shown at the bottom of FIG. 4, the pitch acceleration according to the present embodiment has the same value as that when the attenuation coefficient is always hard from time t1 to time t2. That is, according to the present embodiment, the pitch behavior of the vehicle body 10 can be effectively suppressed during the period in which the rear portion of the vehicle body is most likely to sink due to the front wheel 16 riding on the protrusions 52.

  Further, in the process in which the sprung acceleration shows a negative value, the push-up from the road surface is hardly transmitted to the vehicle occupant. Therefore, between the time t1 and the time t2, even if the damping coefficient Csr of the rear wheel 34 is hard, the riding comfort of the vehicle is not greatly impaired. For this reason, according to this embodiment, the pitch behavior of the vehicle body 10 due to the front wheels 16 riding on the protrusions 52 can be effectively suppressed without impairing the riding comfort of the vehicle.

  As indicated by a solid line 60 in FIG. 4, in this embodiment, when it is detected that the rear wheel sprung acceleration is reversed to a positive value (time t2), the damping coefficient Csr of the rear wheel 34 is changed to a soft value. Is done. That is, in the present embodiment, in a situation where the rear portion of the vehicle body 10 is vibrating due to the protrusion of the front wheel 16, the damping coefficient Csr of the rear wheel 34 is maintained while the sprung acceleration of the rear wheel 34 is a positive value. Is a soft value.

  While positive sprung acceleration is generated at the rear portion of the vehicle body 10, the push-up from the rear wheel 34 is easily transmitted to the vehicle occupant. For this reason, if the damping coefficient Csr is maintained at a hard value under such a situation, it becomes easier for the occupant to feel a push-up. In the present embodiment, since the damping coefficient Csr of the rear wheel 34 is set to a soft value in such a situation, it is possible to effectively suppress the push-up feeling felt by the passenger. Therefore, according to the present embodiment, it is possible to provide a good ride comfort to the vehicle occupant even during the period from time t2 to time t3.

  Furthermore, in this embodiment, after the time t3 when the front wheel 16 passes the protrusion 52, the damping coefficient Csr of the rear wheel 34 is left to normal control. According to the normal control, if a large vibration is generated on the spring of the rear wheel 34, the damping coefficient Csr is set to a hard value. For this reason, if the vibration has not yet converged at the time t3, the damping coefficient Csr is set to a hard value, and the vibration is quickly converged.

[Processing in ECU]
FIG. 5 is a flowchart of a routine executed by the ECU 50 in the present embodiment in order to realize the above function. The routine shown in FIG. 5 is repeatedly started every predetermined sampling time after the vehicle on which the present embodiment is mounted.

  In the routine shown in FIG. 5, first, various sensor values serving as the basis of the sprung displacement amounts Xbf and Xbr and the unsprung displacement amounts Xwf and Xfr of the front wheel 16 and the rear wheel 34 are input to the ECU 50 (step 100). Specifically, the output signals of the laser sensor 12, unsprung acceleration sensors 24 and 40, sprung acceleration sensors 28 and 42, and stroke sensors 30 and 44 are taken into the ECU 50.

  Next, a road surface plane amount Xw representing the average height of the road surface is calculated (step 102). Here, first, based on the sensor value obtained at this sampling timing, the unsprung displacement amount Xwf of the front wheel and the unsprung displacement amount Xwr of the rear wheel are calculated. Next, the average value (Xwf + Xwr) / 2 is calculated. This average value corresponds to the unsprung height at the center of the vehicle at the current sampling time. Then, by reflecting the current average value (Xwf + Xwr) / 2 at a predetermined smoothing rate to the road surface plane amount Xw (n-1) calculated in the previous routine, Updates are made. The road surface plane amount Xw calculated in this way is the smoothed value of the unsprung height at the center of the vehicle, and can be handled as the average height of the road surface on which the vehicle is traveling.

Next, based on the unsprung displacement amounts Xwf and Xwr and the road surface plane amount Xw, it is determined whether or not the front wheel 16 of the vehicle has greatly shifted from the road surface plane amount Xw due to the influence of the road surface unevenness (step 104). Specifically, it is determined here whether the following two conditions are both satisfied.
| Xwf−Xw |> δ1 (Condition 1)
| Xwr−Xw | <δ1 (Condition 2)
δ1 is a threshold value for determining irregularities to be regarded as protrusions (or depressions) in this embodiment, and when the wheel passes over this kind of irregularities, the unsprung displacement amounts Xwf and Xwr and the road surface plane amount Xw This corresponds to the smallest difference that occurs between Therefore, when the above condition 1 is satisfied, it can be determined that the front wheel 16 is passing over the unevenness. Further, when the above condition 2 is satisfied, it can be determined that the rear wheel 34 is traveling on a flat shelf road having no unevenness. When both of these conditions 1 and 2 are satisfied, it can be determined that the rear wheel 34 is on a flat road surface and only the front wheel is riding on the protrusion (or entering the depression). it can. That is, according to the example shown in FIG. 4, the condition of this step 104 is determined to be satisfied only during the time t1 to the time t3, and is determined not to be satisfied during other periods.

  When it is determined that the above condition is not satisfied, that is, when it is determined that only the front wheel 16 is not in the state of riding on the protrusion 52, the normal control is performed for the damping coefficient Csr of the rear wheel 34 thereafter. Is executed (step 106). Specifically, here, when the sprung body (vehicle body 10) moves downward by so-called skyhook control, for example, the damping coefficient Csr of the shock absorber 38 is set to a hard value to strengthen the support from below. In addition, when the sprung moves upward, the damping coefficient Csr is set to a hard value in order to increase the suppression from above. On the other hand, if there is no significant vertical movement on the spring, the damping coefficient Csr is a soft value. According to such normal control, it is possible to ensure good riding comfort while maintaining the vehicle posture stably.

  On the other hand, if it is determined that the condition of step 104 is satisfied, it is then determined whether the sprung acceleration Xbr ″ on the rear wheel 34 side is equal to or less than zero (step 108). “Xbr ″” means a double differential value of Xbr = (d2 / dx2) Xbr. In this embodiment, the value Xbr ″ can be detected by the sprung acceleration sensor 42. On the spring of the rear wheel 34, that is, behind the vehicle body 10, the front wheel 16 starts to oscillate due to the influence of weighted movement after the front wheel 16 enters the unevenness. At this time, the sprung acceleration Xbr ″ repeatedly increases and decreases in the positive region and increases and decreases in the negative region. The condition of this step 106 is satisfied when the sprung acceleration Xbr ″ takes a zero or negative value during the period.

  If it is determined in step 108 that the above condition is satisfied, normal control is executed in step 106 thereafter. When step 106 is executed via step 108, there is a large movement behind the vehicle body 10. For this reason, by performing normal control, the damping coefficient Csr of the rear wheel 34 is set to a hard value. As a result, sinking behind the vehicle body is suppressed, and the pitch amount of the vehicle body 10 is suppressed. In addition, when the sprung acceleration Xbr ″ is zero or negative, it is difficult to transmit the push-up feeling to the passenger. For this reason, even if the attenuation coefficient Csr is hardwareized by the processing of step 108, the riding comfort is not impaired.

  On the other hand, if it is determined in step 108 that the sprung acceleration Xbr ″ on the rear wheel 34 side is not less than zero, that is, positive acceleration Xbr ″ is generated on the spring of the rear wheel 34, Regardless of the request, control is performed with the damping coefficient Csr of the rear wheel 34 as a soft value (step 110). When the sprung acceleration Xbr ″ of the rear wheel 34 shows a positive value, that is, when the upward acceleration Xbr ″ is generated on the spring of the rear wheel 34, the rider feels a push-up feeling from the rear wheel 34. It is easy to be transmitted to. According to the above processing, by setting the damping coefficient Csr of the rear wheel 34 to be soft under such a situation, it is possible to create a situation in which the push-up feeling is not easily transmitted to the passenger. For this reason, according to the control of the present embodiment, the pitch behavior when the front wheels 16 pass through the unevenness can be effectively suppressed without impairing the riding comfort of the vehicle.

  In the example shown in FIG. 4, normal control is executed in step 106 during the period from time t1 to time t2. At this time, since a large movement occurs on the spring of the rear wheel 34, the damping coefficient Csr of the rear wheel 34 becomes a hard value. As a result, the pitch of the vehicle body 10 is effectively suppressed. In the period from time t2 to time t3, in step 108, the damping coefficient Csr of the rear wheel 34 is a soft value. As a result, good riding comfort is ensured in the vehicle. After time t3, normal control is executed again at step 106. At this time, if there is a large movement on the spring, the damping coefficient Csr is a hard value, and if the state on the spring is stable, the damping coefficient Csr is a soft value. As a result, both good riding comfort and stable vehicle behavior are realized. Thus, according to the present embodiment, the pitch behavior of the vehicle body 10 can be effectively suppressed without impairing the riding comfort of the vehicle when the front wheels 16 pass through the unevenness.

[Modification of Embodiment 1]
By the way, in the first embodiment described above, the explanation is made mainly by taking the case where the front wheel 16 passes through the projection 52 on the road surface as an example, but the damping coefficient Csr of the rear wheel 34 is changed by the routine shown in FIG. Is not limited to that case. That is, the damping coefficient Csr of the rear wheel 34 is appropriately changed by the routine shown in FIG. 5 even when the front wheel 16 passes through the recess on the road surface.

  Moreover, in Embodiment 1 mentioned above, although control which switches the damping coefficient Csr of the rear-wheel 34 when the front wheel 16 passes unevenness | corrugation is illustrated, this invention is not limited to this. That is, when the rear wheel 34 passes through the unevenness of the road surface, the damping coefficient Csf of the front wheel 16 may be switched by the control method of the first embodiment.

  Further, in the first embodiment described above, the pitch behavior is suppressed by appropriately controlling the damping coefficient Csr of the rear wheel 34 when the front wheel 16 passes through the unevenness of the road surface, but the behavior that can be suppressed by the present invention. Is not limited to this. That is, when the left and right wheels pass through the road surface unevenness, the roll behavior of the vehicle body 10 may be suppressed by similarly controlling the damping coefficient of the left and right wheels.

  Further, in the first embodiment described above, in step 108, the threshold value to be compared with the sprung acceleration of the rear wheel 34 is set to zero, but the present invention is not limited to this. That is, this threshold value may be set to a non-zero value in accordance with the purpose of suppressing changes in the behavior of the vehicle and the importance of the purpose of realizing good riding comfort.

  In the first embodiment, the unsprung acceleration sensors 24 and 40 or the laser sensor 12 correspond to the “road surface input sensor” in the present invention. The sprung acceleration sensors 28 and 42 or the unsprung acceleration sensors 24 and 40 and the stroke sensors 30 and 44 correspond to the “sprung behavior sensor” in the present invention. Further, the ECU 50 executes the processing of step 104 to realize the “concave / convex determination means” in the present invention, and the processing of step 108 to realize the “push-up determination means” in the present invention. . In addition, the ECU 50 sets the attenuation coefficient Csr to a hard value in the above step 106 so that the “first control means” in the present invention executes the processing in the above step 108, and the “second control” in the present invention Each means is realized.

DESCRIPTION OF SYMBOLS 10 Car body 12 Laser sensor 14, 32 Suspension apparatus 16 Front wheel 18, 36 Spring element 20, 38 Shock absorber 24, 40 Unsprung acceleration sensor 28, 42 Sprung acceleration sensor 30, 44 Stroke sensor
Xwf, Xwr Unsprung displacement
Xbf, Xbr Sprung displacement

Claims (1)

A vehicle suspension control device comprising a spring element and a shock absorber capable of changing a damping coefficient in each wheel of the vehicle,
A road surface input sensor for generating a signal corresponding to the vertical movement of each wheel;
A sprung behavior sensor for generating a signal corresponding to the vertical movement of the vehicle body at the position of each wheel;
An unevenness judging means for judging whether one end wheel located at one end of the vehicle is on the unevenness of the road surface based on the signal of the road surface input sensor,
Based on the signal from the sprung behavior sensor, push-up determination means for determining whether the upward acceleration of the vehicle body at the other end relative to the one end is equal to or less than a threshold value;
A first control means for setting a damping coefficient of a shock absorber located at the other end to a hard value when the one end wheel is on a road surface unevenness and the upward acceleration is equal to or less than the threshold;
The damping coefficient of the shock absorber located at the other end when the one end wheel is on the road surface unevenness and the upward acceleration is not less than or equal to the threshold value is a soft soft value compared to the hard value. A second control means;
A suspension control device for a vehicle, comprising:

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