JP5113882B2 - Damper control device - Google Patents

Description

  The present invention relates to a damper control device for controlling a damping force variable damper provided in a vehicle suspension device.

A technique for varying the damping force of a damper that is provided in a vehicle suspension and absorbs vibration is widely known. For example, Patent Literature 1 discloses a variable damping force type that improves running stability and riding comfort by changing damping force. A technique related to a shock absorber (variable damping force damper) is disclosed.
According to the technique disclosed in Patent Document 1, the vehicle running state is detected, the vehicle posture change is predicted according to the detected running state, and the damping coefficient of the damping force variable shock absorber is predicted according to the predicted posture change. The ride quality can be improved by changing

JP-A-6-115335

  For example, according to the technique disclosed in Patent Document 1, it is estimated that the shrinkage-side damping coefficient of the shock absorber (damper) on the side on which the wheel is supposed to bounce is increased to decrease the expansion-side damping coefficient, and the wheel is rebounded. By increasing the expansion-side damping coefficient of the front-side damper and decreasing the contraction-side damping coefficient, it is possible to suppress changes in posture such as roll and pitching of the vehicle body.

However, the technology disclosed in Patent Document 1 does not take into account riding comfort when the shock absorber (damper) is fully rebounded or fully bumped to the limit.
For example, when the shock absorber on the extension side is further extended depending on the road surface or the like, the shock absorber may extend to the limit of expansion and contraction and fully rebound. Similarly, the shock absorber on the contraction side may contract to the limit of expansion and contraction to make a full bump. When the shock absorber is fully rebounded or fully bumped, the cylinder and the piston constituting the shock absorber collide with each other to generate an impact, and there is a problem that the rider feels a shock or an impact sound due to the impact and deteriorates the riding comfort.

  Accordingly, an object of the present invention is to provide a damper control device that controls a damping force variable damper so as to suppress the occurrence of impact due to full rebound or full bump.

In order to solve the above-described problems, a first aspect of the present invention provides a suspension device that is provided in a suspension device that supports a wheel on a vehicle body and that damps the vibration by expanding and contracting, and a damping force changing device that can change the damping force of the damper. In order to prevent a full rebound and a full bump of the damper when a damper displacement that is a displacement from a steady state of the damper exceeds a predetermined threshold , A first target damping force setting unit that sets the damping force of the damper higher as the damper displacement is larger, and a state in which the damper extends from the steady state and is likely to fully rebound, or the damper is shrunk from the steady state and is a full bump And a traveling state determination unit that determines that the vehicle is in a specific traveling state in which the vehicle travels. The first target damping force setting unit reduces the threshold when the traveling state determination unit determines that the vehicle is traveling in the specific traveling state.

  According to the first aspect of the present invention, the damper control device that increases the damping force and prevents the damper from being fully rebounded and bumped when the damper displacement exceeds the threshold value can reduce the threshold value when the vehicle runs in a specific running state. . Therefore, when the vehicle runs in a specific running state, the damping force of the damping force variable damper can be increased while the damper displacement is small, and the full rebound and full bump of the damper can be suitably suppressed.

  A second aspect of the present invention provides the damper control device according to the first aspect, wherein the first target damping force setting unit is configured to reduce the damping of the damper based on a speed at which the damper is displaced and the damper displacement. If the damper displacement exceeds the threshold when the traveling state determination unit determines that the vehicle is traveling in the specific traveling state, the vehicle travels in the specific traveling state. It is characterized in that the damping force of the damper is set by increasing the rate of change of the damping force of the damper with respect to the change of the damper displacement, compared with the case where the running state determination unit determines that it is not.

  According to the invention of claim 2, when the damper displacement exceeds a threshold value when the vehicle travels in a specific running state, the damper control device determines the rate of change of the damping force of the damping force variable damper with respect to the change of the damper displacement. Can be larger than when the vehicle does not travel in a specific traveling state. Therefore, the damper control device can quickly increase the damping force of the variable damping force damper even with a small damper displacement.

  A third aspect of the present invention is the damper control device according to the first or second aspect, wherein the traveling state determination unit is configured such that the vehicle travels in the specific traveling state when the vehicle turns. It is determined that it is present.

  According to the invention of claim 3, the traveling state determination unit of the damper control device can determine that the turning vehicle is traveling in the specific traveling state, and the wheels inside the turning of the vehicle that are in a roll state when turning. It is possible to avoid the full rebound of the damping force variable damper provided in the suspension device that supports the vehicle and the full bump of the damping force variable damper provided in the suspension device that supports the wheel on the outside of the turn.

  According to a fourth aspect of the present invention, there is provided the damper control device according to any one of the first to third aspects, wherein the running state determination unit determines a lateral acceleration of the vehicle detected by a lateral acceleration detecting means. A lateral acceleration differential value is calculated by time differentiation, and it is determined that the vehicle is traveling in the specific traveling state from when the absolute value of the lateral acceleration differential value starts to decrease to zero. And

  According to the fourth aspect of the invention, the traveling state determination unit of the damper control device can determine that the vehicle is traveling in the specific traveling state based on the rate of change of the lateral acceleration generated in the turning vehicle. Since the roll angle of the turning vehicle changes in synchronization with the lateral acceleration generated in the vehicle, it is determined that the vehicle is running in a specific running state based on the rate of change of the lateral acceleration. It can be determined that the vehicle is traveling in a specific traveling state without delay when the roll angle becomes maximum.

  A fifth aspect of the present invention is the damper control device according to any one of the first to fourth aspects, wherein a second target damping force setting for setting a damping force for damping the grounding side of the damper is set. And a selection means for selecting one of the damping force set by the first target damping force setting unit and the damping force set by the second target damping force setting unit to obtain the damping force of the damper. The second target damping force setting unit sets the damping force so as to logarithmically change with respect to the change in the damper displacement and the change in speed when the damper is displaced.

According to the fifth aspect of the present invention, the damper control device uses one of the damping force set by the first target damping force setting unit and the damping force set by the second target damping force setting unit as the damping force of the damping force variable damper. Can be set. The damping force set by the second target damping force setting unit is set so as to change logarithmically with respect to the change in the damper displacement and the change in the speed when the damper is displaced, thereby avoiding an excessive value. Therefore, when the damping force set by the second target damping force setting unit is set to the damping force of the damping force variable damper, it is avoided that a damping force larger than necessary is set in the damping force variable damper, and the riding comfort is avoided. Can be aggravated.
A sixth aspect of the present invention is the damper control device according to any one of the first to fifth aspects, wherein the damping force changing device supplies an exciting current to an actuator composed of a core and a coil. The first target damping force setting unit is configured to increase the damping force when the damper displacement exceeds the threshold value determined by a current setting map. The excitation current is set with reference to a map and supplied to the actuator, the damping force of the damper is set so as to prevent full rebound and full bump of the damper, and the vehicle travels in the specific traveling state. When the traveling state determination unit determines that the current is in the turning state, the current setting map for turning is set to be larger than the current setting map. Reducing the threshold of the damper displacement by referring to the flop, and supplying to the actuator by setting the excitation current based on the turning-state current setting map.

  ADVANTAGE OF THE INVENTION According to this invention, the damper control apparatus which controls a damping force variable damper so that generation | occurrence | production of the impact by a full rebound or a full bump can be suppressed can be provided.

It is a figure which shows the structural example of the damping force variable damper with which a vehicle is equipped. It is the figure which modeled the damping force variable damper. It is a functional block diagram of a damper control device. (A) is a figure which shows an example of the current setting map for setting a control current, (b) is a figure which shows an example of the current setting map at the time of turning for setting a control current at the time of turning, (c) is at the time of turning It is a figure which shows an example of the electric current and gain setting map for changing a gain and setting a control current. (A) is a figure which shows the vehicle which changes lane, (b) is a graph which shows the lateral acceleration measured value and lateral acceleration differential value which generate | occur | produce in the vehicle which changes lane. It is a functional block diagram of the damper control device concerning a 2nd embodiment. It is a functional block diagram which shows the structure with which the damper control apparatus which concerns on 2nd Embodiment is equipped with a roll / pitch attitude | position control part and a skyhook riding comfort control part.

<< First Embodiment >>
DESCRIPTION OF EMBODIMENTS Hereinafter, a first embodiment for carrying out the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, a wheel 101 of a vehicle 100 is elastically supported on a vehicle body 2 by a suspension device 102, and the suspension device 102 according to the first embodiment includes a damping force variable damper 1.
The damping force variable damper 1 is provided so as to connect the suspension arm 3 that supports the knuckle 4 and the vehicle body 2, a cylinder 8 that is supported at the lower end by the suspension arm 3, and a piston head 9 that slides inside the cylinder 8. The piston rod 10 extends upward from the piston head 9. The cylinder 8 is filled with oil that generates a damping force, and the damper 1a is configured to include the cylinder 8, the piston head 9, and the piston rod 10. The damper 1 a expands and contracts due to the vibration of the suspension arm 3, and absorbs the vibration of the suspension arm 3 with a damping force generated by the resistance of oil sealed in the cylinder 8.

A core 11 is attached to the upper end of the piston rod 10, and a coil 12 is disposed so as to surround the core 11. The core 11 and the coil 12 form the actuator 5. The actuator 5 is a device that increases the damping force of the damper 1a using a magnetic force generated when an excitation current as the control current Icont is supplied to the coil 12, and a damping force that can change the damping force of the damping force variable damper 1 Functions as a change device.
The actuator 5 is preferably configured such that the magnitude of the damping force of the damper 1a can be adjusted by the magnitude of the control current Icont supplied to the coil 12.

The upper part of the core 11 is connected to the vehicle body 2 via an elastic body such as a damper mount rubber 6. Thus, the damping force variable damper 1 according to the first embodiment is configured to include the actuator 5 and the damper mount rubber 6 in addition to the cylinder 8, the piston head 9, and the piston rod 10, and from the steady state of the damper 1a. The displacement (damper displacement) is measured by the damper displacement sensor 14. The steady state here is a state where no load is applied and the damper 1a is not expanded and contracted, and the damper displacement is zero.
The lateral acceleration generated in the vehicle body 2 is measured by a lateral acceleration sensor 15 which is a lateral acceleration detecting means, and the longitudinal acceleration generated in the vehicle body 2 is measured by a longitudinal acceleration sensor 16.

  Further, a flange portion 8 a that extends outward is formed on the outer periphery of the cylinder 8, and a coil spring 7 is disposed between the flange portion 8 a and the vehicle body 2. The coil spring 7 is provided so as to absorb, for example, vertical vibration generated in the wheel 101 with an elastic force.

  Reference numeral 20 denotes a damper control device that controls the damping force variable damper 1. Details of the configuration and functions of the damper control device 20 will be described later.

As shown in FIG. 1, the suspension device 102 including the damping force variable damper 1 and the coil spring 7 can be modeled, for example, as shown in FIG. In the model shown in FIG.
The damping force variable damper 1 includes a coil spring 7 between an unsprung mass Wt2 that is the mass on the vehicle body 2 (see FIG. 1) side above and an unsprung mass Wt1 that is the mass on the wheel 101 side that is below the ground. At the same time, the sprung mass Wt2 is elastically supported, and the coil spring 7 becomes an elastic element, and the damping force variable damper 1 becomes a viscous element. The damping force of the damping force variable damper 1 that is a viscous element is configured to be changeable by an actuator 5 (see FIG. 1).

In the model shown in FIG. 2, the sprung mass Wt2 corresponds to the mass of an element supported by the damping force variable damper 1 and the coil spring 7 such as the vehicle body 2 (see FIG. 1), and the unsprung mass Wt1 corresponds to the coil spring 7 and the damping. This corresponds to the mass of the wheel 101, the knuckle 4, the suspension arm 3 and the like that are connected to the vehicle body 2 via the force variable damper 1.
The unsprung mass Wt1 is connected to the wheel 101 via a virtual elastic member (virtual spring SP1). The virtual spring SP1 includes the elasticity of the suspension arm 3 and the like.

In the model shown in FIG. 2, the damper displacement of the damper 1a (see FIG. 1) is indicated by a displacement difference dX obtained by subtracting the displacement X1 of the unsprung mass Wt1 from the displacement X2 of the unsprung mass Wt2, and when the damper 1a is extended. When the displacement difference dX is positive and the damper 1a is contracted, the displacement difference dX is negative.
Therefore, the damper displacement sensor 14 (see FIG. 1) measures the displacement difference dX and outputs the measured value as the displacement measurement value STsns.
Further, the vertical acceleration of the sprung mass Wt2 is measured by the sprung acceleration sensor 13 (see FIG. 1).

  The differential value (d · X2 / dt) of the displacement X2 of the sprung mass Wt2 indicates the vertical speed of the sprung mass Wt2, and the differential value (d · dX / dt) of the displacement difference dX is the damper 1a (see FIG. 1). Shows the speed (displacement speed SV) when the is displaced.

  Thus, the damping force variable damper 1 provided in the suspension device 102 absorbs the vibration of the wheel 101 by the damping force of the damper 1a (see FIG. 1) while expanding and contracting, and the vibration of the wheel 101 is absorbed by the vehicle body 2 (see FIG. 1). Suppresses being transmitted. At this time, when the damper 1a is fully extended and the damper displacement reaches the limit of expansion and contraction and fully rebounds, or when the damper 1a is fully contracted and the damper displacement reaches the limit of expansion and contraction and full bumps, the cylinder 8 and the piston head shown in FIG. The impact caused by the collision of 9 occurs and the riding comfort deteriorates. Therefore, it is preferable to avoid the damper 1a from being fully rebounded or fully bumped.

Full rebound and full bump of the damper 1a (see FIG. 1) can be avoided, for example, by increasing the damping force. However, if the damping force of the damper 1a is always kept high, the vibration of the wheel 101 (see FIG. 1) Riding comfort is deteriorated by being transmitted to the vehicle body 2 (see FIG. 1).
Further, when the damping force of the damper 1a configured as shown in FIG. 1 is increased, it is necessary to supply the exciting current as the control current Icont to the coil 12 (see FIG. 1) of the actuator 5, and the damping force of the damper 1a is reduced. Keeping it high all the time increases power consumption.

Therefore, in the first embodiment, the traveling state when the vehicle 100 (see FIG. 1) travels in a state where the damper 1a (see FIG. 1) is likely to be fully rebounded and fully bumped is defined as the specific traveling state. The damping force of the damper 1a is increased only when traveling in the traveling state.
For example, when the vehicle 100 turns, the vehicle 100 rolls and the damper 1a (see FIG. 1) of the variable damping force damper 1 provided in the suspension device 102 (see FIG. 1) that supports the wheel 101 (see FIG. 1) inside the turn. Will be in a state where it tends to fully rebound, and the damper 1a of the damping force variable damper 1 provided in the suspension device 102 that supports the wheel 101 on the outer side of the turn will be shrunk and will be in a state where full bumps are likely to occur.

Therefore, in the first embodiment, the state in which the vehicle 100 (see FIG. 1) turns is set as a specific traveling state in which the damper 1a is likely to be fully rebounded and fully bumped. Then, when the vehicle 100 turns, the damping force of the damper 1a is increased, so that the damper 1a extends and fully rebounds, and the damper 1a contracts to avoid full bumps.
In the first embodiment, setting the damping force of the damper 1a to prevent full rebound and full bump of the damper is to increase the damping force of the damper 1a.

Therefore, the damping force variable damper 1 according to the first embodiment is controlled by a damper control device 20 mainly including a first target damping force setting unit 20a and a differentiator 20b as shown in FIG. 3, for example. To be configured. The damper controller 20 includes a damper displacement measurement value (displacement measurement value STsns) of the damper 1a (see FIG. 1) measured by the damper displacement sensor 14 and a lateral acceleration measurement value (lateral) measured by the lateral acceleration sensor 15. Acceleration measurement value G1sns) is input.
The differentiator 20b differentiates the displacement measurement value STsns to calculate the displacement speed SV, and the displacement measurement value STsns, the displacement speed SV, and the lateral acceleration measurement value G1sns are input to the first target damping force setting unit 20a. To do.

The first target damping force setting unit 20a sets the damping force of the damper 1a (see FIG. 1) based on the measured displacement value STsns, the displacement speed SV, and the lateral acceleration measured value G1sns, and sets the set damping force to the damper 1a. The control current Icont supplied to the coil 12 (see FIG. 1) of the actuator 5 is set as a control signal.
For example, the first target damping force setting unit 20a sets the control current Icont when at least one of the displacement measurement value STsns and the displacement speed SV exceeds a predetermined threshold.

  Since the damping force variable damper 1 is provided for each of the four wheels 101 (see FIG. 1) provided in the vehicle 100 (see FIG. 1), the vehicle 100 is provided with four damping force variable dampers 1. Therefore, the damper control device 20 includes the four first target damping force setting units 20a, and is configured to set the control current Icont for each of the damping force variable dampers 1.

  Since the damping force of the damper 1a shown in FIG. 1 is set by a control current Icont supplied to the coil 12 of the actuator 5, the first target damping force setting unit 20a is based on the displacement measurement value STsns and the displacement speed SV. A damping force to be set to the damper 1a is determined, and further, a control current Icont to be supplied to the coil 12 of the actuator 5 is set in order to set the determined damping force to the damper 1a.

  Therefore, the first target damping force setting unit 20a includes a control signal setting unit 21a and a traveling state determination unit 21b as shown in FIG. 3, and the control signal setting unit 21a includes, for example, the displacement measurement value STsns and the displacement speed. Based on the SV, a control signal (control current Icont) is set with reference to a preset map. The traveling state determination unit 21b determines whether the vehicle 100 (see FIG. 1) is turning based on the lateral acceleration measurement value G1sns, and generates a vehicle state signal Vsig based on the determination result. The vehicle state signal Vsig may be a signal that can indicate at least two phenomena of whether or not the vehicle 100 is turning.

  Further, as shown in FIG. 4A, the control signal setting unit 21a is a first map (relationship between measured displacement values STsns, displacement speed SV, and control signals (control currents IcontI1 to I3) for controlling the actuator 5). A current setting map MP1) is provided.

In the current setting map MP1 shown in FIG. 4A, when the displacement measurement value STsns is equal, the higher the displacement speed SV, the higher the control current Icont is set, and when the displacement speed SV is equal, the displacement measurement value STsns is higher. It shows that the set control current Icont is high. That is, I1 (solid line) to I3 (one-dot chain line) of the current setting map MP1 indicate current values set in the control current Icont, and there is a relationship of “I1 <I2 <I3”. A region smaller than the current value I1 (region between the origin 0 and the solid line indicating the current value I1) indicates a region where the current value is zero.
The quadrant in which both the displacement measurement value STsns and the displacement speed SV are positive (the upper right quadrant in the figure) indicates the current value set in the damping force variable damper 1 on the expansion side, and both the displacement measurement value STsns and the displacement speed SV are negative. The quadrant (lower quadrant in the figure) indicates the current value set in the damping force variable damper 1 on the contraction side.

  The control signal setting unit 21a shown in FIG. 3 sets the control current Icont by referring to the current setting map MP1 according to the displacement measurement value STsns input from the damper displacement sensor 14 and the displacement speed SV input from the differentiator 20b. To do. For example, as shown in FIG. 4A, when the displacement speed SV is SV1 and the displacement measurement value STsns is ST1 (point P1), the control signal setting unit 21a sets the control current Icont to the current value I1. If the displacement measurement value STsns is ST3 smaller than ST1 when the displacement speed SV is SV1 (point P3), the control signal setting unit 21a sets the control current Icont to zero. If the displacement measurement value STsns is greater than ST1 when the displacement speed SV is SV1, the control signal setting unit 21a sets the current value for the displacement measurement value STsns as the control current Icont on the current setting map MP1. For example, if the displacement measurement value STsns is ST2 (point P2), the control signal setting unit 21a sets the control current Icont to the current value I2.

  That is, the solid line indicating the current value I1 in the current setting map MP1 is a line indicating a threshold value for setting the control current Icont according to the displacement speed SV, and when the displacement measurement value STsns exceeds the threshold value indicated by the solid line, A control current Icont that is equal to or greater than the value I1 is set.

Furthermore, the control signal setting unit 21a according to the first embodiment is configured to set a control current Icont by referring to when the traveling state determination unit 21b determines that the vehicle 100 (see FIG. 1) is turning. As a map, a turning current setting map MP2 shown in FIG.
When the vehicle 100 is turning, the control signal setting unit 21a determines that the damper 1a (see FIG. 1) of the damping force variable damper 1 is likely to be fully rebounded and fully bumped, and the current setting shown in FIG. The turning current setting map MP2 different from the map MP1 is referred to according to the input displacement measurement value STsns and the displacement speed SV, and the control current Icont is set.
The turning current setting map MP2 is a map in which a current value with respect to the displacement measurement value STsns is set larger than that of the current setting map MP1.

  Therefore, in the case of the point P1 where the displacement speed SV is SV1 and the displacement measurement value STsns is ST1, when the control signal setting unit 21a refers to the current setting map MP1, the current value I1 is set as the control current Icont. When the unit 21a refers to the turning current setting map MP2, the current value I2 is set as the control current Icont. As described above, the turning current setting map MP2 is set with a larger control current Icont with the same displacement measurement value STsns than the current setting map MP1. Further, in the case of the point P3 where the displacement speed SV is SV1 and the displacement measurement value STsns is ST3 smaller than ST1, when the control signal setting unit 21a refers to the turning current setting map MP2, the current value I1 is set as the control current Icont. However, when the control signal setting unit 21a refers to the current setting map MP1, the control current Icont becomes zero. That is, the control current Icont is not set.

  Therefore, the turning current setting map MP2 can be said to be a map in which the control signal setting unit 21a decreases the threshold value of the displacement measurement value STsns for setting the control current Icont. Then, the control signal setting unit 21a refers to the turning current setting map MP2 to reduce the threshold value of the displacement measurement value STsns for setting the control current Icont.

Further, as the second map, a current / gain setting map MP3 shown in FIG. 4C may be provided instead of the turning current setting map MP2 shown in FIG. 4B.
Similar to the current setting map MP2, the current / gain setting map MP3 reduces the threshold value of the displacement measurement value STsns for setting the control current Icont and increases the current value with respect to the displacement measurement value STsns, compared to the current setting map MP1. In addition to being set, this is a map in which the increase rate of the current value with respect to the increase of the displacement measurement value STsns is set larger than the current setting map MP1.

  For example, in the case of the point P1 where the displacement speed SV is SV1 and the displacement measurement value STsns is ST1, when the control signal setting unit 21a refers to the turning current setting map MP2, the current value I2 is set as the control current Icont. When the signal setting unit 21a refers to the current / gain setting map MP3, the current value I3 is set as the control current Icont.

Thus, in the current / gain setting map MP3, in the region where the displacement measurement value STsns is larger than the threshold value, the rate of increase of the control current Icont relative to the increase of the displacement measurement value STsns indicates the current setting map MP1 or the turning current setting map. It is larger than MP2, and as the displacement measurement value STsns increases, the current value of the control current Icont can be quickly increased and the damping force of the damper 1a can be increased.
That is, the current / gain setting map MP3 is a map for setting the damping force by increasing the rate of change of the damping force with respect to the change of the displacement (displacement measurement value STsns) of the damper 1a.

  On the other hand, the turning current setting map MP2 shown in FIG. 4B shows the displacement measurement value STsns for setting the control current Icont without changing the increase rate of the control current Icont with respect to the increase of the displacement measurement value STsns. It is a map that makes only the threshold value smaller than the current setting map MP1, and is a map that sets the damping force without changing the rate of change of the damping force with respect to the change of the displacement (displacement measurement value STsns) of the damper 1a.

With such a configuration, the control signal setting unit 21a (see FIG. 3) allows the traveling state determination unit when the vehicle 100 (see FIG. 1) is turning, that is, when the vehicle 100 is traveling in a specific traveling state. When 21b determines, a threshold value for setting the control current Icont by referring to the turning current setting map MP2 (see FIG. 4B) or the current / gain setting map MP3 (see FIG. 4C) is set. Can be small.
Further, when the current / gain setting map MP3 is provided as the second map, the control signal setting unit 21a is configured such that when the vehicle 100 is traveling in the specific traveling state, the vehicle 100 is not traveling in the specific traveling state ( The rate of change of the damping force with respect to the change of the displacement measurement value STsns (the rate of change of the current value of the control current Icont) can be made larger than when the running state determination unit 21b determines that the vehicle 100 is not running in the specific running state. .

  The control signal setting unit 21a (see FIG. 3) according to the first embodiment refers to a map to be referred to in the current setting map MP1 (see FIG. 3) according to the vehicle state signal Vsig input from the traveling state determination unit 21b (see FIG. 3). The control current Icont is set by switching between the turning current setting map MP2 (see FIG. 4B) or the current / gain setting map MP3 (see FIG. 4C). . Specifically, when the vehicle state signal Vsig indicates that the vehicle is turning, the control signal setting unit 21a refers to the turning current setting map MP2 or the current / gain setting map MP3 according to the input displacement measurement value STsns and the displacement speed SV. When the control current Icont is set and the vehicle state signal Vsig indicates other than turning, the control current Icont is set by referring to the current setting map MP1 according to the input displacement measurement value STsns and the displacement speed SV. .

Further, the traveling state determination unit 21b (see FIG. 3) according to the first embodiment is configured so that the vehicle 100 (see FIG. 1) is based on the lateral acceleration measurement value G1sns input from the lateral acceleration sensor 15 (see FIG. 3). Determine that the car is turning.
For example, when the vehicle 100 changes lanes as shown in FIG. 5A, the vehicle 100 turns left and right and the measured value of the lateral acceleration (lateral G) generated in the vehicle 100 (lateral acceleration measured value G1sns) 5 as shown in (b). (1) to (5) described in (b) of FIG. 5 correspond to states (1) to (5) shown in (a) of FIG.

  In the state (1) in which the vehicle 100 is traveling straight, no lateral G is generated in the vehicle 100, and the lateral acceleration measurement value G1sns measured by the lateral acceleration sensor 15 is zero. In the state (2) in which the vehicle 100 turns rightward, a lateral G is generated in the vehicle 100, and the lateral acceleration measurement value G1sns indicates the lateral G value. Thereafter, in a state (3) in which the vehicle 100 travels straight, the lateral G and lateral acceleration measurement value G1sns of the vehicle 100 become zero. In the state (4) in which the vehicle 100 turns leftward, a lateral G in the opposite direction to the state (2) occurs in the vehicle 100, the lateral acceleration measurement value G1sns indicates the lateral G value, and the vehicle 100 travels straight. In the state (5), the lateral G of the vehicle 100 and the lateral acceleration measurement value G1sns are zero.

For example, the traveling state determination unit 21b determines that the vehicle 100 is turning during the lane change of the vehicle 100, that is, the period indicated by (1) to (5) in FIG. Also good. However, the state where the vehicle 100 is turning is a state where the damping force of the damper 1a (see FIG. 1) is high, and the riding comfort is deteriorated. Therefore, it is preferable that this state is short.
Therefore, it is more preferable that the damper 1a is determined to be the turning state of the vehicle 100 when the damper 1a is most likely to be fully rebounded and fully bumped. With this configuration, the state in which the damping force of the damper 1a is high can be shortened, and the state in which riding comfort is deteriorated can be shortened. Therefore, deterioration of riding comfort can be reduced.

In the turning vehicle 100, when the roll angle of the vehicle 100 is the maximum, the damper 1 a (see FIG. 1) of the damping force variable damper 1 provided on the turning wheel 101 (see FIG. 1) is most likely to extend and fully rebound. It is known that the damper 1a of the damping force variable damper 1 provided on the wheel 101 on the outer side of the turn is in the most contracted state and is likely to be fully bumped.
Therefore, the traveling state determination unit 21b according to the first embodiment is configured to detect a state in which the roll angle of the turning vehicle 100 is maximum, and to determine that the turning angle of the vehicle 100 is the maximum when the turning angle is maximum. It is preferable to do.

  Since the roll angle of the turning vehicle 100 is generated in the same phase as the lateral G generated in the vehicle 100, the roll angle is maximized when the lateral G generated in the vehicle 100 is the maximum. Therefore, when the lateral acceleration measurement value G1sns changes as shown by the solid line in FIG. 5B, the roll angle of the vehicle 100 is maximized at the point where the lateral acceleration measurement value G1sns is maximized.

  However, if the traveling state determination unit 21b determines the turning of the vehicle 100 when the lateral acceleration measurement value G1sns becomes the maximum, the roll angle is maximized when the traveling state determination unit 21b determines the turning of the vehicle 100. Therefore, even if the control signal setting unit 21a supplies the control current Icont to the coil 12 (see FIG. 1) of the actuator 5 based on the determination of the traveling state determination unit 21b, the damper is used when the roll angle is maximum. The damping force of 1a cannot be increased.

  Therefore, the traveling state determination unit 21b according to the first embodiment calculates a differential value (lateral acceleration differential value (d · G1sns / dt)) obtained by time-differentiating the lateral acceleration measurement value G1sns and calculates the absolute value of the lateral acceleration differential value. It is determined that the vehicle 100 is turning from when the value starts to decrease until it reaches zero. For example, the traveling state determination unit 21b determines that the vehicle 100 is turning from the as point to the ae point and from the bs point to the be point shown in FIG. 5B, and the vehicle 100 turns. A vehicle state signal Vsig indicating that the vehicle is running is output. That is, the traveling state determination unit 21b determines that the vehicle 100 is turning (traveling in a specific traveling state) from when the absolute value of the differential value of the lateral acceleration measurement value G1sns starts to decrease to zero.

With this configuration, the control signal setting unit 21a can supply the control current Icont to the coil 12 (see FIG. 1) of the actuator 5 prior to the state in which the lateral acceleration measurement value G1sns is the maximum and the roll angle is the maximum. When the angle is maximized, the damping force of the damper 1a (see FIG. 1) can be increased. Therefore, the damping force of the damper 1a can be increased when the damper 1a is most likely to be fully rebounded or fully bumped, and the damper 1a can be prevented from being fully rebounded or fully bumped.
Furthermore, the damping force of the damper 1a can be increased only when the roll angle is in the maximum state, and the duration of the state in which the riding comfort is deteriorated can be shortened. Therefore, deterioration of riding comfort can be reduced.

  Thus, the damping force variable damper 1 (see FIG. 1) according to the first embodiment is supplied to the coil 12 (see FIG. 1) of the actuator 5 when the vehicle 100 (see FIG. 1) is turning. By reducing the threshold value for setting the current Icont, the damping force of the damper 1a can be increased in a state where the damper displacement of the damper 1a is small. Therefore, the damper 1a can be prevented from full rebound and full bump.

  Further, when the damper displacement of the damper 1a (see FIG. 1) is larger than the threshold value when the vehicle 100 (see FIG. 1) is turning, the damper displacement is increased compared to when the vehicle 100 is not turning. The increase rate of the current value can be increased, and the damping force of the damper 1a can be quickly increased as the damper displacement increases. Therefore, the damper 1a can be prevented from full rebound and full bump.

  Furthermore, the damping force of the damper 1a can be increased only when the damper displacement of the damper 1a (see FIG. 1) becomes maximum due to turning of the vehicle 100 (see FIG. 1), and the damper 1a fully rebounds or bumps. In addition to avoiding this, it is possible to shorten the state in which the riding comfort deteriorates by increasing the damping force of the damper 1a. Therefore, the deterioration of riding comfort can be suitably reduced.

The current setting map MP1 shown in FIG. 4A, the turning current setting map MP2 shown in FIG. 4B, and the current / gain setting map MP3 shown in FIG. 4C are examples. However, it is not limited to setting the current value in three stages of I1 to I3. For example, it may be a current setting map MP1, a current setting map MP2 during turning, a current / gain setting map MP3 that sets current values in four or more steps, or a current setting map MP1 that sets current values in two steps or less, turning The hour current setting map MP2 and the current / gain setting map MP3 may be used.
The region between the solid line indicating the current value I1 and the broken line indicating the current value I2 may be a region indicating the current value I1, or may be a region that gradually increases from the current value I1 toward the current value I2. There may be. When the region between the solid line indicating the current value I1 and the broken line indicating the current value I2 indicates a region that gradually increases from the current value I1 toward the current value I2, for example, a point P1 shown in FIG. The control signal setting unit 21a can set the current value of the control current Icont by proportional distribution or the like when it is between the solid line indicating the value I1 and the broken line indicating the current value I2. The same applies to the region between the broken line indicating the current value I2 and the one-dot chain line indicating the current value I3.

<< Second Embodiment >>
The second embodiment of the present invention is different from the damper control device 20 according to the first embodiment in the configuration of a damper control device that controls the damping force variable damper 1 (see FIG. 1).
As shown in FIG. 6, the damper control device 30 according to the second embodiment includes an unsprung target damping force setting unit 30c and a high level selector 30d in addition to the first target damping force setting unit 30a and the differentiator 30b. The damping force variable damper 1 is controlled instead of the damper control device 20 shown in FIG.
The first target damping force setting unit 30a and the differentiator 30b function in the same manner as the first target damping force setting unit 20a and the differentiator 20b of the damper control device 20 shown in FIG.

Further, the displacement measurement value STsns measured by the damper displacement sensor 14 and the displacement speed SV calculated by differentiating the displacement measurement value STsns by the differentiator 30b are input to the unsprung target damping force setting unit 30c.
The unsprung target damping force setting unit 30c controls (vibrates) the vibration of the unsprung mass Wt1 shown in FIG. 2 and sets a control signal for suppressing the resonance of the unsprung mass Wt1. The setting unit includes a gain generator 31a, a multiplier 31b, and an output corrector 31c. The gain generator 31a generates a preset control gain K1, and the multiplier 31b multiplies the displacement measurement value STsns, the displacement speed SV, and the control gain K1 to generate a control signal (current) before correction to correct the output. Input to the device 31c.
The control gain K1 is a characteristic value determined in advance according to the specifications and configuration required for the damping force variable damper 1. The unsprung target damping force setting unit 30c sets a control signal to be supplied to the coil 12 (see FIG. 1) of the actuator 5 similarly to the first target damping force setting unit 20a (see FIG. 3). A damping force for damping the mass Wt1 is set.

  The output corrector 31c has a function of correcting the pre-correction control signal (current) so that an excessive control signal is not output from the unsprung target damping force setting unit 30c. In the second embodiment, the output corrector 31c Configured to output logarithm. That is, a value proportional to log (IN) is output with respect to the input signal IN. The control signal output by the output corrector 31c is an unsprung control current Ib supplied to the coil 12 (see FIG. 1) of the actuator 5.

  As described above, the unsprung target damping force setting unit 30c includes the output corrector 31c that outputs the logarithm of the input value, so that the spring changes so that the logarithm changes with respect to the change in the control signal before correction output from the multiplier 31b. The lower control current Ib can be set. With this configuration, it is possible to prevent the unsprung control current Ib from becoming excessive even when the pre-correction control signal output from the multiplier 31b has an excessive value.

  The first target damping force setting unit 30a has the same configuration as the first target damping force setting unit 20a according to the first embodiment shown in FIG. 3, and includes a displacement measurement value STsns, a displacement speed SV, and a lateral acceleration measurement value. A damping force control current Ia is output as a control signal for controlling the damping force variable damper 1 based on G1sns.

The unsprung target damping force setting unit 30c sets and outputs the unsprung target control current Ib and the first target damping force setting unit 30a sets and outputs the damping force control current Ia is input to the high level selector 30d. . The high level selector 30d is selection means for selecting one of the input unsprung control current Ib and damping force control current Ia and outputting it as a control current Icont and supplying it to the coil 12 of the actuator 5 (see FIG. 1). is there.
The unsprung control current Ib corresponds to the damping force set by the unsprung target damping force setting unit 30c, and the damping force control current Ia corresponds to the damping force set by the first target damping force setting unit 30a. The selector 30d selects one of the damping force set by the unsprung target damping force setting unit 30c and the damping force set by the first target damping force setting unit 30a as the damping force of the damper 1a (see FIG. 1). It becomes a selection means.

  The damper control device 30 configured as described above is configured so that the unsprung control current Ib output from the unsprung target damping force setting unit 30c is greater than the damping force control current Ia output from the first target damping force setting unit 30a. The unsprung control current Ib is selected as the control current Icont supplied to the fifth coil 12 (see FIG. 1). Accordingly, the damping force control current Ia output from the first target damping force setting unit 30a when the damper 1a (see FIG. 1) is in a specific running state in which the vehicle 100 (see FIG. 1) is turning or the like is likely to be fully rebounded or fully bumped. Since a larger unsprung control current Ib is supplied to the coil 12 of the actuator 5, the damping force of the damper 1a can be suitably increased, and the damper 1a can be prevented from being fully rebounded or fully bumped.

  Further, since the control current Icont changes logarithmically with respect to the change in the control signal before correction calculated by the multiplier 31b (see FIG. 6), the damper 1a (see FIG. 1) is prevented from being fully rebounded or fully bumped. The current value can be kept small in a range higher than the current value required for the above, and the increase in the damping force of the damper 1a can be suppressed to the minimum necessary. Accordingly, it is possible to reduce the deterioration of the ride comfort of the passenger.

  As a modification of the second embodiment, as shown in FIG. 7, a roll / pitch attitude control unit 30e including a roll attitude control unit and a pitch attitude control unit and a skyhook riding comfort control unit 30f are provided. 1 damping force control current Ia output from the target damping force setting unit 30a, unsprung control current Ib output from the unsprung target damping force setting unit 30c, and roll / pitch control current output from the roll / pitch attitude control unit 30e. The maximum current among the Ic and the skyhook control current Id output from the skyhook ride control unit 30f may be output as the control current Icont.

  The configuration of the skyhook ride control unit 30f and the calculation method of the skyhook control current Id, the configuration of the roll attitude control unit and the pitch attitude control unit, and the calculation method of the roll / pitch control current Ic, The technology described in Japanese Patent Application Laid-Open No. 2006-69527 filed can be used.

Even in the damper control device 30 configured as described above, the first target is set when the damper 1a (see FIG. 1) is in a specific traveling state in which the vehicle 100 (see FIG. 1) is turning, or the damper 1a (see FIG. 1) is likely to be fully rebounded or fully bumped. A control current Icont that is greater than or equal to the damping force control current Ia output from the damping force setting unit 30a can be supplied to the coil 12 (see FIG. 1) of the actuator 5, and the damper 1a can be prevented from being fully rebounded or fully bumped.
Furthermore, elements such as skyhook control and roll / pitch control can be added to improve riding comfort.

  Note that the design of the present invention can be changed as appropriate without departing from the spirit of the invention. 2 is configured to determine the turning of the vehicle 100 (see FIG. 1) based on the lateral acceleration measurement value G1sns input from the lateral acceleration sensor 15, for example, a steering handle (not shown) It may be configured to determine the turning of the vehicle 100 based on the steering angle, or may be configured to determine the turning of the vehicle 100 based on the yaw rate generated in the vehicle 100.

  Further, the damping force changing device that changes the damping force of the damper 1 a shown in FIG. 1 is not limited to the configuration including the actuator 5 having the coil 12 and the core 11. For example, the configuration may be such that the damping force is changed by changing the diameter of the orifice through which the oil enclosed in the cylinder 8 flows, and changing the resistance of the oil.

DESCRIPTION OF SYMBOLS 1 Damping force variable damper 1a Damper 2 Car body 5 Actuator (Damping force changing device)
8 cylinder 9 piston head 15 lateral acceleration sensor (lateral acceleration detecting means)
20, 30 Damper control device 20a, 30a First target damping force setting unit 21b Traveling state determination unit 30c Unsprung target damping force setting unit (second target damping force setting unit)
30d High level selector (selection means)
31c Output corrector 100 Vehicle 101 Wheel 102 Suspension device Wt1 Unsprung mass Wt2 Sprung mass

Claims (6)

A suspension device that supports the wheel on the vehicle body, and a damper that expands and contracts to attenuate vibrations,
A damping force changing device capable of changing the damping force of the damper, and controlling a damping force variable damper configured to include:
When the damper displacement, which is a displacement from the steady state of the damper, exceeds a predetermined threshold value, the damping force of the damper is set to be higher as the damper displacement is larger so as to prevent full rebound and full bump of the damper. A first target damping force setting unit;
A traveling state determination unit that determines that the damper is in a specific traveling state in which the damper travels from the steady state and is likely to be fully rebounded, or the damper is contracted from the steady state and is likely to be fully bumped. A damper control device comprising:
The damper control device according to claim 1, wherein the first target damping force setting unit reduces the threshold when the traveling state determination unit determines that the vehicle is traveling in the specific traveling state. The first target damping force setting unit sets the damping force of the damper based on the speed at which the damper is displaced and the damper displacement,
When the damper displacement exceeds the threshold when the traveling state determination unit determines that the vehicle is traveling in the specific traveling state,
The damping force of the damper is set by increasing the rate of change of the damping force of the damper with respect to the change of the damper displacement than when the running state determination unit determines that the vehicle is not running in the specific running state. The damper control device according to claim 1, wherein: The traveling state determination unit
3. The damper control device according to claim 1, wherein the damper control device determines that the vehicle is traveling in the specific traveling state when the vehicle turns. The traveling state determination unit
A lateral acceleration differential value is calculated by temporally differentiating the lateral acceleration of the vehicle detected by the lateral acceleration detecting means,
4. The method according to claim 1, wherein the vehicle is determined to be traveling in the specific traveling state from when the absolute value of the lateral acceleration differential value starts to decrease to zero. 5. The damper control device according to claim 1. A second target damping force setting unit for setting a damping force for damping the grounding side of the damper;
Selecting means for selecting one of the damping force set by the first target damping force setting unit and the damping force set by the second target damping force setting unit to be the damping force of the damper;
The second target damping force setting unit sets the damping force so as to logarithmically change with respect to the change in the damper displacement and the change in speed when the damper is displaced. The damper control device according to any one of 4. The damping force changing device is configured to increase the damping force of the damper with a magnetic force generated by supplying an excitation current to an actuator including a core and a coil as a load,
The first target damping force setting unit is
When the damper displacement exceeds the threshold determined by the current setting map, the excitation current is set with reference to the current setting map and supplied to the actuator to prevent full rebound and full bump of the damper. Set the damping force of the damper to
A turning current setting map in which the excitation current with respect to the damper displacement is set larger than the current setting map when the traveling state determination unit determines that the vehicle is traveling in the specific traveling state; 6. The threshold value of the damper displacement is reduced by referring to the excitation current, which is set based on the turning current setting map and supplied to the actuator. The damper control device according to claim 1.

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