JP6259237B2 - Damper control device - Google Patents

Description

  The present invention relates to a damper control device.

  In a damper control device that controls the damping force of a damper interposed between a sprung member and an unsprung member of a vehicle, for example, the amount of current supplied to a solenoid valve provided in the damper is adjusted. Some adjust the damping force of the damper.

  In such a damper control device, the damping force characteristic of the damper can be adjusted from soft to hard by supplying a current amount corresponding to the damping force characteristic of the damper to the solenoid. When setting the damping force characteristic of the soft to the solenoid, a constant amount of current corresponding to the soft damping force characteristic is supplied to the solenoid, and when setting the hard damping force characteristic, the constant corresponding to the hard damping force characteristic is set. Is supplied to the solenoid (see, for example, Patent Document 1).

JP-A-11-287281

  In such a damper control device, unless the sprung member in the vehicle vibrates greatly, a constant current is supplied to the solenoid to cause the damper to exhibit a predetermined damping force characteristic, so that the sprung member and the unsprung member in the vehicle. The vibration of the member can be suppressed, and the riding comfort in the vehicle can be improved.

Thus, although the resulting good ride in conventional damper control device, there is a case where the vehicle damping force is too large when overcoming the projections of the road surface, the sprung from the unsprung member as pushed up It is difficult to suppress an impact shock in which a large acceleration is transmitted to the member, and further improvement in riding comfort is desired.

  In addition, using Skyhook control that exerts a damping force according to the speed of the sprung member is effective for reducing impact shock, but the low frequency vibration of the sprung member is excited. When traveling on the road surface, the sprung member is controlled to be flat, and the sprung member does not follow the undulation of the road surface, which may make the vehicle occupant feel uncomfortable.

  Therefore, the present invention was devised to improve the above-described problems, and an object of the present invention is to provide a damper control device that can improve road surface followability while reducing impact shock. It is.

In order to achieve the above object, the problem-solving means of the present invention is a damper control device for controlling a damping force of a damper interposed between a sprung member and an unsprung member in a vehicle. A low-frequency component detection unit that detects the low-frequency component, and a control unit that controls the damping force of the damper based on the low-frequency component, and the control unit calculates a correction gain based on the low-frequency component. A correction gain generation unit to be obtained; and a control command correction unit that corrects a control command for controlling the damper with a correction gain, and the damping force of the damper is controlled using the corrected control command. And

In the damper control device, the damping force of the damper is controlled based on the low frequency component of the expansion / contraction speed of the damper. By increasing the damping force, the road surface followability of the sprung member can be improved, and in a situation where the damper is apt to increase its contraction speed and the damper is slowly contracting, the damping force can be reduced. Impact shock input to the sprung member can be reduced.
Insulation of vibration transmission from the unsprung member to the unsprung member when the vehicle gets over a protrusion or recess on the road surface can be improved, and fluttering of the unsprung member can be suppressed to quickly suppress the unsprung member. be able to.

  Therefore, according to the damper control device of the present invention, road surface followability can be improved while reducing impact shock.

It is a schematic block diagram of the damper control apparatus in one embodiment. It is a schematic longitudinal cross-sectional view of the damper controlled by a damper control apparatus. It is a block diagram of a damper control device. It is the figure which showed the waveform of the level calculation signal produced | generated in a signal production | generation part. It is the figure which showed the frequency phase characteristic of the level calculation signal. It is the figure which showed the waveform of the absolute value of the level calculation signal produced | generated in a signal production | generation part. It is the figure which showed the waveform of the absolute value of the level calculation signal with respect to the input of the original signal from which frequency differs. It is a map which shows the relationship between a vibration level and a level gain. It is a map which shows the relationship between the low frequency component of the expansion-contraction speed of a damper, and correction | amendment gain.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, the damper control device E controls the damping force in the damper D interposed between the sprung member B and the unsprung member W in the vehicle in this example, A low frequency component detection unit 1 that detects a low frequency component Dv of the expansion / contraction speed of the damper D and a control unit 2 that controls the damping force of the damper D based on the low frequency component are provided.

  In this example, the damper D is arranged in parallel with the suspension spring VS and interposed between the sprung member B and the unsprung member W in the vehicle, and the sprung member B is elastically supported by the suspension spring VS. . The unsprung member W includes a wheel and a link that are swingably attached to a sprung member B that is a vehicle body.

  The damper D is, for example, as shown in FIG. 2, a cylinder 12, a piston 13 slidably inserted into the cylinder 12, and a slidably inserted into the cylinder 12 and coupled to the piston 13. The piston rod 14, the two pressure chambers 15, 16 partitioned by the piston in the cylinder 12, the damping force adjusting passage 17 communicating with the pressure chambers 15, 16, and the flow of fluid passing through the damping force adjusting passage 17 The hydraulic pressure damper is configured to include a proportional solenoid valve 18 as a damping force adjusting unit that provides resistance. The damper D exerts a damping force that suppresses the expansion / contraction operation by applying resistance to the proportional solenoid valve 18 when the fluid filled in the pressure chamber passes through the passage according to the expansion / contraction operation. The relative movement of the member B and the unsprung member W is suppressed.

Hydraulic oil in the cylinder 12, water, and the liquid is filled such solution, the proportional solenoid valve 18, for example, to change the damping characteristics of the damper D in accordance with the magnitude of the current supplied from the control section 2 Be able to. The proportional solenoid valve 18 includes, for example, a valve body that makes the damping area of the damping force adjustment passage 17 (not shown) of the damper D variable, and the flow area of the damping force adjustment passage 17 by driving the valve body. It may be configured with a solenoid that can be adjusted. However, an actuator other than the solenoid may be used to drive the valve body, and the flow of the damping force adjusting passage 17 can be increased or decreased by increasing or decreasing the amount of current applied to the actuator. The damping force generated by the damper D can be adjusted by changing the resistance given to the fluid flowing through the damping force adjusting passage 17 by adjusting the road area.

  In addition to the proportional solenoid valve 18, the damping force adjusting unit is a device that applies a magnetic field to the damping force adjusting passage 17 when the fluid is a magnetorheological fluid, and is supplied from the damper control device E. The damping force of the damper D may be made variable by adjusting the magnitude of the magnetic field according to the amount of current to be changed and changing the resistance applied to the flow of the magnetorheological fluid passing through the damping force adjusting passage 17. Further, when the fluid is an electrorheological fluid, the damping force adjusting unit may be a device that can apply an electric field to the damping force adjusting passage 17, and the electric field is generated by a voltage supplied from the damper control device E. The damping force generated by the damper D may be made variable by changing the resistance given to the fluid flowing through the damping force adjusting passage 17 by adjusting the size of the damping force adjusting passage 17.

  Further, when the fluid is a liquid and the damper D is a single rod type damper, the damper D includes a gas chamber and a reservoir to compensate for the volume of the piston rod 14 entering and exiting the cylinder 12. In the case of gas, the gas chamber and the reservoir may not be provided. When the damper D is provided with a reservoir and is set to a uniflow type in which fluid is discharged through a passage from the cylinder 12 to the reservoir even if the damper D is extended or contracted, the damper D is attenuated in the middle of the passage from the cylinder 12 to the reservoir. A force adjusting unit may be provided to exert a damping force by giving resistance to the fluid flow.

  Further, in addition to the above, the damper D may be an electromagnetic damper that exhibits a damping force that suppresses relative movement of the sprung member B and the unsprung member W by electromagnetic force. As the electromagnetic damper, for example, a motor And a motion conversion mechanism that converts the rotational motion of the motor into a linear motion, or a linear motor. In this way, when the damper D is an electromagnetic damper, the damping force adjustment unit may be a motor drive device that adjusts the current flowing through the motor or linear motor.

  Hereinafter, each part will be described. As shown in FIGS. 1 and 3, the low-frequency component detection unit 1 includes a stroke sensor 21 that detects the stroke displacement of the damper D, a differentiator 22 that determines a damper speed from the damper displacement detected by the stroke sensor 21, and a differentiator And a band-pass filter 23 that filters the damper speed obtained at 22 to extract a low-frequency component Dv of the damper speed.

  Although not shown in detail, the stroke sensor 21 is interposed between the sprung member B and the unsprung member W, and detects the stroke displacement of the damper D. The stroke sensor 21 may be provided integrally with the damper D. The differentiator 22 differentiates the stroke displacement to obtain a damper speed, and outputs the damper speed. In the band-pass filter 23, the low frequency component Dv of the expansion / contraction speed of the damper D is a component that depends on the vibration state of the sprung member B. The band frequency is extracted as a low frequency component and output. The transmission frequency band of the bandpass filter 23 is a sprung resonance frequency band, and the filtered low frequency component Dv includes a sprung resonance frequency component, but does not include a sprung resonance frequency component. .

In the case of this embodiment, the control unit 2 includes a vibration level generation unit 30 that calculates the vibration level VL of the sprung member B, a level gain generation unit 31 that generates a level gain LG based on the vibration level VL, and a vibration level. The vibration level correction unit 32 that corrects the vibration level VL by multiplying VL by the level gain LG, the control command generation unit 33 that generates the control command I based on the corrected vibration level VL ^* , and the low frequency component Dv A speed correction unit 34 that multiplies the level gain LG to correct the low frequency component Dv, a correction gain generation unit 35 that calculates the correction gain HG based on the corrected low frequency component Dv ^* , and the correction gain HG as the control command I. A control command correction unit 36 for obtaining a corrected control command I ^* by multiplying and correcting, and a proportional solenoid valve 18 as a damping force adjusting unit according to the corrected control command I ^*. The drive part 37 to drive is comprised.

  As shown in FIG. 3, the vibration level generation unit 30 uses the low frequency component Dv of the damper speed detected by the low frequency component detection unit 1 as an original signal O, and uses the original signal O to make two phases different in phase. In this example, the signal generator 30a that generates the five level calculation signals L1 to L5 and the maximum value among the absolute values of the level calculation signals L1 to L5 are obtained, and the maximum value is set as the vibration level. And a level calculator 30b.

  The signal generation unit 30a obtains five level calculation signals L1 to L5 that have the same amplitude as the original signal O but have different phases. Specifically, in order to obtain the level calculation signal Ln (n = 1, 2, 3, 4, 5) from the original signal O, the signal generation unit 30a does not change the amplitude with respect to the original signal O, but only the phase. Phase change filters F1 to F5 are provided, and these phase change filters F1 to F5 are arranged in parallel, and the original signal O is filtered by the phase change filters F1 to F5. The number of phase change filters may be provided corresponding to the number of level calculation signals L1 to L5. In this case, five phase change filters may be provided.

  The transfer functions G (s) of the phase change filters F1 to F5 are set by the following equation (1). In Equation (1), O (s) represents the Laplace conversion amount of the original signal O, and Ln (s) (n = 1, 2, 3, 4, 5) represents the level calculation signal Ln (n = 1, 2, 3, 4, 5) represents the Laplace transform amount, s represents the Laplace operator, and ωn (n = 1, 2, 3, 4, 5) represents the frequency ω 1 Different frequencies are set up to ω5.

  Therefore, in order to obtain the level calculation signal Ln (n = 1, 2, 3, 4, 5), the signal generator 24 sets the frequency as ωn (n = 1, 2, 3, 4, 5). Using the phase change filter Fn (n = 1, 2, 3, 4, 5) having the transfer function G (s), the level calculation signal Ln (n = 1, 2, 3, 4, 5) is obtained from the original signal O. 5). For example, in order to obtain the level calculation signal L4, the signal generation unit 30a filters the original signal O with a phase change filter F4 having a transfer function G (s) set by inputting ω4 as a frequency, and the original signal The level calculation signal L4 is obtained from O.

When the level generation signals L1 to L5 are obtained by the signal generation unit 30a using the phase change filters F1 to F5 as described above, the amplitude does not change with respect to the original signal O of a certain frequency x as shown in FIG. Five level calculation signals L1 to L5 whose phases are different from each other can be easily obtained. The phase difference between the original signal O and the level calculation signal L1 and the phase difference between the level calculation signals L1 to L4 are equally spaced, but the phase difference between the level calculation signal L4 and the level calculation signal L5 is the original signal O. And the phase difference between the level calculation signals L1 and the other level calculation signals L1 to L5. This frequency-phase characteristic of the level calculation signal L1～L 5 is, is as shown in FIG. 5, has a characteristic that varies in a range of -180 degrees lower from 0 ° limit, 0 ° and Limited by -180 degrees. The phase of the level calculation signals L1 to L5 is 0 degrees or near 0 degrees when the frequency of the original signal is extremely low, and is −180 degrees or near −180 degrees when the frequency of the original signal is extremely high. It becomes. Therefore, as shown in FIG. 4, in the level calculation signals L1 to L4 obtained by filtering the original signal O of the frequency x, the phase differences are arranged at equal intervals, but the phase of the level calculation signal L5 is The phase difference from the adjacent level calculation signal L4 becomes smaller as it approaches -180 degrees. Note that the transfer function G (s) of the phase change filters F1 to F5 may be set by the following equation (2). In equation (2), O (s) represents the Laplace transform amount of the original signal O, and Ln (s) (n = 1, 2, 3, 4, 5) represents the level calculation signal Ln (n = 1, 2, 3, 4, 5) represents the Laplace transform amount, s represents the Laplace operator, and ωn (n = 1, 2, 3, 4, 5) represents the frequency ω 1 to ω 5. Up to different frequencies are set.

  Further, the phase change filters F1 to F5 can be secondary low-pass filters. Specifically, the transfer function G (s) of the phase change filters F1 to F5 may be set by the following equation (3). In equation (3), O (s) represents the Laplace transform amount of the original signal O, and Ln (s) (n = 1, 2, 3, 4, 5) represents the level calculation signal Ln (n = 1, 2, 3, 4, 5) indicates the Laplace transform amount, s indicates the Laplace operator, ζ is the attenuation factor, and ωn (n = 1, 2, 3, 4, 5) is the cut Different cut-off frequencies are set from ω1 to ω5 indicating the off-frequency.

  If the low-pass filter is used for the phase change filters F1 to F5, the phase of the level calculation signals L1 to L5 can be delayed with respect to the original signal O, and if the high-pass filter is used, the level calculation signals L1 to L1 Since the phase of L5 can be advanced, it is also possible to use a high pass filter for a part of the phase change filters F1 to F5 and use a low pass filter for the rest of the phase change filters F1 to F5.

  Furthermore, since the signal generation unit 30a obtains the level calculation signals L1 to L5 having different phases from the original signal O, the signal generation unit 30a is delayed by a predetermined time with respect to the original signal O without using the above-described filter processing. The generated signals may be generated as level calculation signals L1 to L5.

  The level calculation unit 30b obtains the maximum value among signals obtained by performing absolute value processing on the original signal O and the level calculation signals L1 to L5. When the absolute value processing is performed on the original signal O and each of the level calculation signals L1 to L5, the waveforms of the original signal O and the level calculation signals L1 to L5 after the absolute value processing are as shown in FIG. A portion having a negative value in the waveforms of L1 to L5 looks like a positive side around the time axis. Since the absolute values of the original signal O and the level calculation signals L1 to L5 are different from each other, even if the absolute value processing is performed on the level calculation signals L1 to L5, the original signal O and the level calculation signal after the processing are processed. The waveforms in L1 to L5 are shifted in time.

  By processing in this way, the maximum value of the original signal O and the level calculation signals L1 to L5 after absolute value processing is equal to or equal to the maximum amplitude of the original signal O at any time in FIG. It turns out that it becomes an approximate value. For example, the maximum value of the original signal O and level calculation signals L1 to L5 after absolute value processing at time a becomes the maximum value of the level calculation signal L2, and the original signal O and level calculation signals L1 to L1 after absolute value processing at time b are set. The maximum value of L5 is a value that approximates the value of the maximum amplitude of the original signal O.

  Since the maximum amplitude of the level calculation signals L1 to L5 is equal to the maximum amplitude at the speed of the original signal O, and the original signal O is the low frequency component Dv of the expansion / contraction speed of the damper D and substantially equal to the speed of the sprung member B, The maximum amplitude of the original signal O is equal to the vibration level VL of the sprung member B when the speed is taken as a scale. That is, the maximum value when the original signal O is one cycle is the vibration level of the sprung member B, but if one cycle is sampled, the vibration level VL of the sprung member B can be obtained in a timely manner. If the frequency of vibration of the sprung member B changes, the maximum amplitude cannot be obtained because the time required for one cycle changes. However, as described above, the amplitude is the same as that of the original signal O. When the level calculation signals L1 to L5 having different phases only are generated, at the time of calculating the vibration level VL, either the original signal O after absolute value processing or the level calculation signals L1 to L5 is the maximum value or close to the maximum value. It can be expected to be a value, and the maximum value of the original signal O and the level calculation signals L1 to L5 after the absolute value processing is obtained to obtain the vibration level VL. , It is possible to obtain a vibration level VL as the maximum amplitude value itself or a value which approximates to the original signal O.

  For example, as shown in FIG. 7, even if an original signal O having a frequency y lower than the frequency x is input, the original signal O and the level calculation signals L1 to L5 whose phases are different from those of the original signal O. Since the maximum value at the time of calculation is obtained and set as the vibration level VL, the vibration level VL is a value of the maximum amplitude of the original signal O or a value approximate thereto. That is, even if the frequency of the original signal O changes, a value that approximates the value of the maximum amplitude of the original signal O can be obtained as the vibration level VL.

  In FIG. 7, the phase difference between the level calculation signals L1 to L5 is equal, but the phase difference between the original signal O and the level calculation signal L1 is different from the other level calculation signals L1 to L5. The phase difference between the two is different. As shown in FIG. 5, although the phase of the original signal O is constant at 0 degrees, the phase of the level calculation signal L1 is limited to the upper limit of 0 degrees when the frequency is lowered. The phase difference from the original signal O becomes small near 0 degrees. Further, in the region where the frequency is low, the phase difference between the level calculation signal L1 and the adjacent level calculation signal L2 is also small. However, even if the frequency is lowered, a level approximate to the value of the maximum amplitude of the original signal O can be obtained as the vibration level VL by the level calculation signals L2 to L5 in which the phase differences are equally spaced. Thus, even if the frequency of the original signal O changes, the value of the maximum amplitude of the original signal O or a value close to it can be obtained as the vibration level VL in real time and in a timely manner. On the other hand, the vibration level VL can be obtained with high accuracy.

  Further, since the vibration level VL obtained in this embodiment is a speed at which the original signal O is vibration information of the sprung member B, the vibration level VL is detected in this way, so that the vibration of the sprung member B is detected. The level of vibration (vibration level) can be detected in a timely and real-time manner, and the vibration level obtained in this way has little time delay with respect to the vibration of the sprung member B. It can withstand use for the suppression control. In the above-described embodiment, the vibration level VL of the sprung member B is obtained using the original signal O and the level calculation signals L1 to L5. However, the vibration level VL of the sprung member B is obtained from the original signal O. If three or more level calculation signals having different phases in the desired frequency band are generated, the vibration level VL of the sprung member B can be obtained with high accuracy, and the original signal O is not used in the level calculation unit 30b. The vibration level VL of the sprung member B may be obtained by executing the above procedure using only the level calculation signal.

  Furthermore, although the phase change filters F1 to F5 process the original signal O in parallel to obtain the level calculation signals L1 to L5, the phase change filters F1 to F5 can be arranged in series. . For example, the original signal O is processed by the filter F1 to obtain the level calculation signal L1, the level calculation signal L1 is processed by the phase change filter F2 to obtain the level calculation signal L2, and the subsequent phase change filter F2 It is also possible to obtain a level calculation signal by processing the level calculation signal processed by the immediately preceding phase change filter by the immediately following phase change filter in ~ F5.

Here, as described above, the frequency phase characteristic of the level calculation signal changes in the range from 0 degree at the upper limit to −180 degrees as the lower limit as shown in FIG. 5, and approaches 0 degree when the frequency is lowered. they become closer to higher becomes the -180 degrees, the phase between your original signal O and the level calculation signal L1~L4 becomes equal intervals with respect to high frequency x, a maximum amplitude or to the original signal O The approximate vibration level VL can be obtained, and for the low frequency y, the phase of the level calculation signals L1 to L5 processed by the phase change filters F1 to F5 is equally spaced, and the maximum amplitude of the original signal O or this Can be obtained.

  That is, the vibration level VL can be detected with high accuracy with respect to the original signal O from the high frequency x to the low frequency y. From the above, it is the level calculation signals L1 to L4 generated by the original signal O and the phase change filters F1 to F4 that contribute to the detection of the vibration level VL with respect to the original signal O of the frequency x. It is understood that the phase change filters F1 to F5 contribute to the detection of the vibration level VL with respect to the signal O, and the phase change filter that contributes to the detection of the vibration level VL changes depending on the frequency of the original signal O.

  Therefore, when it is desired to expand the frequency band in which the vibration level VL of the sprung member B can be detected with high accuracy, the original signal O is used together with the level calculation signal within the range from the lower limit to the upper limit of the frequency band. O and at least two or more level calculation signals may be distributed with a phase difference of equal intervals within a range of 180 degrees, and the vibration level VL of the sprung member B is obtained using only the level calculation signal. It is preferable that at least three or more level calculation signals are dispersed with equal phase differences within a range of 180 degrees. Therefore, the number of filters that generate the level calculation signal may be determined according to the number of level calculation signals generated.

  Therefore, with respect to the input of the original signal O, the signal generation unit 3 has a phase difference between the original signal O and the level calculation signals L1 to L5 that contribute to the detection of the vibration level VL within a range of 180 degrees and equal intervals of 60 degrees or less. If the level calculation signals L1 to L5 are generated so as to be dispersed by the vibration level, the vibration level VL can be detected for signals in a wide frequency band, and the accuracy is improved. This is because, if the signal is expressed by a sine wave, three level calculation signals that are out of phase by 60 degrees are generated to determine the vibration level VL, and the vibration level VL is at least 0.85 of the wave height of the original signal O of the object. Since it does not fall below twice, a favorable vibration level VL can be obtained. When the original signal O is used only for generation of the level calculation signal, the signal generation unit 30a outputs the level calculation signals L1 to L5 that contribute to the detection of the vibration level VL within 60 degrees to 60 degrees or less. If it is generated so as to be distributed with equal phase differences, the vibration level VL can be detected for signals in a wide frequency band, and the accuracy is improved.

  Furthermore, when the number of generated level calculation signals having a constant phase difference within a range of 180 degrees with respect to the input of the original signal O of a certain frequency is large and the phase difference between the level calculation signals is small, the level calculation is performed. In addition to the absolute value of the signal being the vibration level VL, the second and third largest values are used as the vibration level VL, and the average value of the maximum value and the second largest value is also used as the vibration level VL. There is no problem. For example, when the signal is a sine wave, if twelve level calculation signals are generated with a phase difference of 15 degrees, the vibration level VL is obtained even if the third largest value of the absolute value of the level calculation signal is set as the vibration level VL. Since at least 0.9 times the wave height of the original signal O of the object does not fall, a favorable vibration level VL can be obtained. Of course, since the maximum value of the absolute values of the level calculation signal is the closest to the actual vibration level VL, it is preferable to obtain the maximum value as the vibration level VL.

  In addition, as shown in FIG. 3, if the vibration level VL output from the level calculation unit 30b is processed by the low-pass filter 30c, ripples can be removed from the obtained vibration level VL, and the vibration level VL changes suddenly. Can be suppressed.

  In the above description, when the vibration level VL is detected, a level calculation signal is generated and the maximum value is set to the vibration level VL. However, any of the displacement, speed, and acceleration of the sprung member B can be arbitrarily selected. Since the maximum amplitude value of the selected information may be adopted as the vibration level, one of displacement, velocity, and acceleration is selected, and the length of the combined vector of the selected information and the integral value or derivative value of the selected information is selected. What is necessary is just to obtain the vibration level. Furthermore, when detecting the vibration level VL, the vibration level VL may be obtained by separately acquiring vibration information such as the acceleration, speed, and displacement of the sprung member B without using the output of the low-frequency component detection unit 1. .

  The level gain generator 31 generates a level gain LG based on the vibration level VL obtained as described above. Specifically, the level gain generating unit 31 maps the relationship between the vibration level VL and the level gain LG in advance, and uses this map to perform map calculation using the vibration level VL as a parameter to obtain the level gain LG. . In the map, as shown in FIG. 8, the level gain LG takes 1 in the range where the vibration level VL is up to the predetermined value α, and when the vibration level VL exceeds the predetermined value α, the level gain LG gradually becomes 0 with respect to the increase in the vibration level VL. It has come to decrease. For example, if the level gain LG monotonously decreases when the vibration level VL exceeds a predetermined value α, the level gain LG is obtained using an arithmetic expression using the vibration level VL as a parameter without using map calculation. It may be. The predetermined value α and the map can be arbitrarily set, and may be determined in consideration of the upper limit value allowed for the vibration level VL when applied to the vehicle in which the damper control device E is actually used.

The vibration level correction unit 32 corrects the vibration level VL by multiplying the vibration level VL by the level gain LG obtained as described above, and inputs the corrected vibration level VL ^* to the control command generation unit 33. The control command generator 33 outputs a control command I by multiplying the corrected vibration level VL ^* by the control gain.

  It is also possible to input the vibration level VL directly from the vibration level generator 30 to the control command generator 33 without correcting the vibration level VL. Since the vibration of the frequency slightly higher than the sprung resonance frequency band cannot be completely removed by the bandpass filter 23, the low-frequency component Dv of the expansion / contraction speed of the damper D detected by the low-frequency component detection unit 1 is A frequency component slightly higher than the resonance frequency band is also included. The vibration in a frequency band slightly higher than the sprung resonance frequency input to the sprung member B due to vibration input from the road surface while the vehicle is running excites the vibration of the sprung member B and is detected by the low frequency component detection unit 1. When the vibration level VL is generated from the low frequency component Dv to be generated, the vibration level VL may become a very large value. Then, the control command I also becomes large and the damping force may become excessive. Therefore, when the vibration level VL exceeds the predetermined value α, the vibration level VL is corrected by multiplying the vibration level VL by a level gain LG that is greater than 0 and less than or equal to 1. By doing so, it is possible to prevent the control command I from becoming excessive.

  Since the level gain LG obtained by the level gain generating unit 31 is also used for correcting the low frequency component Dv, in this embodiment, a method of obtaining the level gain LG from the vibration level VL and multiplying it by the vibration level VL. However, if it is not necessary to correct the low frequency component Dv with the level gain LG, the level gain generator 31 may be omitted, or the vibration level VL may be replaced with the level gain generator 31. You may make it provide the limiter which clamps the upper limit of this.

The speed correction unit 34 multiplies the low frequency component Dv of the expansion / contraction speed of the damper D by the level gain LG generated by the level gain generation unit 31 to correct the low frequency component Dv to obtain a corrected low frequency component Dv ^* .

The correction gain generation unit 35 generates a correction gain HG from the low frequency component Dv ^* of the expansion / contraction speed of the damper D. Specifically, the correction gain generation unit 35 maps the relationship between the low frequency component Dv ^* and the correction gain HG in advance, and uses this map to calculate the map using the corrected low frequency component Dv ^* as a parameter. To obtain a correction gain HG. In the map, as shown in FIG. 9, if the sign of the speed when the damper D expands is negative and the sign of the speed when the damper D contracts is positive, the value of the low frequency component Dv ^* is negative and the damper D If it is the extension state, the correction gain HG is set to take one or more values, the correction gain HG becomes 1 when the value of the low-frequency component Dv ^* is 0, the low-frequency component Dv ^* of When the value is positive and the damper D is in the contracted state, the correction gain HG is set to take a value of 0 or more and less than 1. More specifically, the upper limit and the lower limit of the correction gain HG are set ^{. When} the value of the low frequency component Dv ^* is equal to or less than the predetermined value β, the correction gain HG takes the upper limit value, and the value of the low frequency component Dv ^* is the predetermined value. Above γ, the correction gain HG takes a lower limit value. Note that setting the upper and lower limits of the correction gain HG in this way prevents the correction gain HG from increasing or decreasing indefinitely. In particular, the lower limit of the correction gain HG is set to 0 or more. The correction gain HG is a gain multiplied by the control command I as will be described later, and the upper limit thereof may be set to 1.3 and the lower limit thereof may be set to about 0.7. However, the correction gain HG is arbitrarily set to be suitable for the vehicle. be able to. Predetermined value beta, gamma can be arbitrarily set, the map becomes the correction gain HG 1 when the characteristics showing the relationship between the low-frequency component Dv ^* and the correction gain HG low frequency component Dv ^* is 0 The correction gain HG gradually decreases from the upper limit to the lower limit as the low frequency component Dv ^* increases. The map for obtaining the correction gain HG shown in FIG. 9 is a map obtained by normalizing the correction gain HG, and is an example of a map for obtaining the correction gain HG. When the correction gain HG is not normalized, The correction gain HG does not have to be a map that is always 1 when the value of the low frequency component Dv ^* is 0. When the control command I is multiplied by a predetermined gain in advance, the product of the correction gain HG and the predetermined gain is set to 1 when the value of the low frequency component Dv ^* is 0, and the product When the value of the low frequency component Dv ^* is negative, the correction gain HG is 1 or more, and when the value of the low frequency component Dv ^* is positive, the correction gain HG is set to 0 or more and less than 1. A map to be set may be used. That is, the correction gain generator 35 may set a correction gain HG that increases the control command I when the value of the low frequency component Dv ^* is negative, and the control command when the value of the low frequency component Dv ^* is positive. What is necessary is just to set the correction gain HG which makes I small.

Note that the low-frequency component Dv is corrected using the level gain LG because the band-pass filter 23 cannot completely remove the frequency component slightly higher than the sprung resonance frequency band. in correcting low-frequency component Dv becomes excessive stretching speed gain of the damper D for detecting HG also because it is likely to be excessive, multiplied by the level gain LG by correcting the low frequency components D v, It is possible to suppress the correction gain HG from becoming too large. However, the correction of the low frequency component Dv by the level gain LG can be omitted. Further, the correction gain HG may be corrected by multiplying the correction gain HG by the level gain LG instead of correcting the low frequency component Dv by the level gain LG.

The control command correction unit 36 corrects the control command I by multiplying the correction gain HG obtained as described above and the control command I generated by the control command generation unit 33 to obtain a corrected control command I ^* . The corrected control command I ^* obtained in this way is input to the drive unit 37. The drive unit 37 includes, for example, a PWM circuit and supplies current to the proportional solenoid valve 18 in accordance with the control command I ^* obtained by the control command correction unit 36. In this case, since the damping force adjustment unit is the proportional solenoid valve 18, the control command I ^* output to the drive unit 37 is a current command.

  The proportional solenoid valve 18, which is a damping force adjusting unit in the damper D, receives a current supplied from the driving unit 37 and adjusts the damping force characteristic in the damper D. And the damper D will exhibit the damping force according to the expansion-contraction speed at that time, and the damping force of the damper D is controlled by the damper control apparatus E. FIG.

As described above, the damper control device E generates the correction gain HG based on the low frequency component Dv of the expansion / contraction speed of the damper D, and generates the control command I ^* by correcting the control command I with the correction gain HG. Then, a current is applied to the proportional solenoid valve 18 serving as a damping force adjusting unit in accordance with a control command to control the damping force of the damper D.

  By the way, while the damper D is slowly extended, when the vehicle passes through the projection on the road surface and the unsprung member W is pushed up, the damper D tries to shrink. Since the speed component obtained by subtracting the speed component toward the slow extension side from the speed component is reduced, the speed component is relaxed by the speed component toward the slow extension side and hardly increases.

The correction gain HG has a value of 1 or more when the low-frequency component Dv of the expansion / contraction speed of the damper D is negative. Therefore, the control command I ^* ≧ the control command I, and the damper D is attenuated. The force is induced to increase. When the damper D is slowly extended, that is, when the low-frequency component Dv of the extension speed of the damper D takes a negative value indicating that the damper D is in the extended state, the damping force indicated by the control command I ^* is The damping force indicated by the control command I before correction tends to be larger.

As described above, in a situation where the damper D is slowly extended, the contraction speed of the damper D is not easily increased due to the slow speed component toward the extension side, and the damping force generated by the damper D even when riding on the road surface protrusion. since the hard impact shocks from the less likely occurs significantly, by correcting to increase the control command I ^*, it is possible to improve the road holding properties of the sprung member B.

  On the other hand, when the vehicle passes through the projection on the road surface and the unsprung member W is pushed up while the damper D is slowly shrinking, the damper D tries to shrink. Since the speed component on the slow contraction side is superimposed on the speed component, the speed component on the slow contraction side is assisted and tends to increase.

When the low-frequency component Dv of the expansion / contraction speed of the damper D is positive, the correction gain HG is less than 1 and a value of 0 or more. Therefore, the control command I ^* <control command I and the damper D The damping force is induced to be small. When the damper D is contracting slowly, that is, when the low frequency component Dv of the expansion / contraction speed of the damper D takes a positive value indicating that the damper D is contracting, the damping force indicated by the control command I ^* is The damping force indicated by the control command I before correction is smaller.

As described above, in a situation where the damper D is contracting slowly, the contraction speed of the damper D tends to increase due to the slow speed component toward the contraction side, and the damping force generated by the damper D even when riding on the road surface protrusion. Impact shock is likely to occur because of the tendency to increase. In this case, since the control command I ^* is corrected and becomes smaller than the control command I, the impact shock can be reduced in order to reduce the damping force of the damper D.

  As described above, in the damper control device E according to the present invention, in a situation where impact shock is unlikely to occur, the damping force of the damper D can be increased to improve the road surface followability of the sprung member B. In a situation where the person can feel a sense of security and an impact shock is likely to occur, the damping force of the damper D can be reduced to reduce the impact shock. Therefore, according to the damper control device E of the present invention, the road surface followability can be improved while reducing the impact shock.

  In the damper control device E according to the present embodiment, since the control command I is generated based on the vibration level VL of the sprung member B, vibration can be effectively suppressed. In other words, when the vibration is controlled by simply detecting only the speed of the sprung member B, the damping force calculated by the control device becomes small when the vibration speed becomes zero, which is necessary for vibration suppression. However, the magnitude of vibration can be grasped by generating and controlling the control command I using the vibration level VL. The control for increasing the damping force can be performed and the vibration can be effectively suppressed. In addition, when the expansion / contraction speed of the damper D is low but the speed of the sprung member B is high, if the control command is obtained directly from the speed of the sprung member B, the control command becomes excessive and the riding comfort in the vehicle is deteriorated. Although there is a possibility, since the damper control device E of the present invention obtains the vibration level VL and obtains the control command I from this vibration level VL, the control command I can be prevented from becoming excessive, It is possible to maintain a good ride comfort in the vehicle. In the damper control device E of the present embodiment, the control command I is generated by the damper control device E itself. However, the control command I is corrected by the correction gain HG in response to the input of the control command I from the outside. You may make it do. Note that the control command I may be obtained from the vibration level of any one of the pitch, roll, and bounce of the entire vehicle body that is the sprung member B. Further, the control unit 2 obtains the control command I by multiplying the vibration level VL by the gain, but the control command I is not limited to this, and the control command I is performed by performing map calculation using an arbitrary map from the vibration level VL. You may ask for.

  Further, in the damper control device E according to the present embodiment, the resonance frequency component of the sprung member B is included in the low frequency component Dv of the expansion speed of the damper D, so that the vibration level VL is set to the expansion speed of the damper D. It is obtained based on the low frequency component Dv, and it is economical because it is not necessary to separately provide a sensor for grasping the vibration state of the sprung member B in order to obtain the control command I.

The vibration level VL includes a level gain generator 31 that generates a level gain LG as a value less than 1 when the vibration level VL is equal to or greater than the predetermined value α, and a vibration level correction unit 32 that multiplies the vibration level VL by the level gain LG. Since the control command I is generated based on the vibration level VL ^* , it is possible to prevent the control command I from being excessive and the damping force from being excessive, thereby further improving the riding comfort in the vehicle. .

Further, the speed correction unit 34 that corrects the low frequency component Dv by multiplying the low frequency component Dv by the level gain LG is provided, and the correction gain HG is generated based on the corrected low frequency component Dv ^*. It is possible to prevent the vehicle from becoming too large, to prevent the control command I ^{* from} becoming excessive and the damping force from becoming excessive, and to improve the riding comfort in the vehicle. The same effect can be obtained by correcting the correction gain HG by multiplying the correction gain HG by the level gain LG.

  In the damper control device E according to the present invention, the damper D using the proportional solenoid valve 18 is controlled, so that the damping characteristic of the expansion pressure of the damper D is reduced for the vehicle without impairing the riding comfort by the amount of current supplied to the proportional solenoid valve 18. Since it has been optimized, the damping force of the damper D can be controlled simply by making a control command by multiplying the vibration level VL by a proportional gain, and without performing complicated calculations to obtain the control command from the vibration level VL. In both cases, the ride comfort in the vehicle can be reliably improved by simply applying this control.

  Further, since the proportional solenoid valve 18 is used for the damping force adjusting unit, the control command in the control unit 2 is a current command, but a command suitable for the damping force adjusting unit may be used as the control command. Therefore, as described above, in addition to the proportional solenoid valve 18, for example, when the damping force adjustment unit is composed of a rotary valve and a stepping motor, the control command may be the number of pulses generated, and the fluid in the damper D In the case of an electrorheological fluid, the damping force adjusting unit generates an electric field, so that the control command may be a voltage command.

  In the case of this embodiment, the damper control device E is not illustrated as a hardware resource, but specifically, for example, an A / D converter for capturing a signal output from the stroke sensor 21, a vibration A storage device such as a ROM (Read Only Memory) in which a program used for processing necessary for level detection and calculation of the current value I is stored, and a CPU (Central Processing Unit) that executes processing based on the program. An arithmetic device and a storage device such as a RAM (Random Access Memory) that provides a storage area to the CPU may be included, and the CPU executes the program so that the low-frequency component detection unit 1 and the control unit are controlled. The operation of the unit 2 may be realized.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

  The vehicular damper of the present invention can be used for vibration control of a vehicle.

DESCRIPTION OF SYMBOLS 1 Low frequency component detection part 2 Control part 12 Cylinder 13 Piston 14 Piston rods 15 and 16 Pressure chamber 17 Damping force adjustment path 18 Proportional solenoid valve 30 Vibration level generation part 31 Level gain generation part 32 Vibration level correction part 33 Control command generation part 34 Speed correction unit 35 Correction gain generation unit 36 Control command correction unit B Sprung member D Damper E Damper controller W Unsprung member

Claims (6)

In a damper control device for controlling a damping force of a damper interposed between a sprung member and an unsprung member in a vehicle,
A low frequency component detector for detecting a low frequency component of the expansion and contraction speed of the damper;
A control unit for controlling the damping force of the damper based on the low frequency component ,
The control unit includes a correction gain generation unit that calculates a correction gain based on the low-frequency component, and a control command correction unit that corrects a control command for controlling the damper with the correction gain. A damper control device that controls a damping force of the damper using a command . The correction gain generation unit sets the correction gain so as to increase the control command when the low-frequency component indicates that the damper is in an extended state, and the low-frequency component indicates that the damper is in a contracted state. The damper control device according to claim 1 , wherein the correction gain is set to reduce the control command. The control unit, the damper control device according to claim 1 or 2, characterized in that generating the control command based on the vibration level of the sprung member. The damper control device according to claim 3 , wherein the vibration level is obtained based on the low frequency component. The control unit includes a level gain generation unit that generates a level gain based on the vibration level, and a vibration level correction unit that multiplies the vibration level by the level gain, and the control command based on the corrected vibration level. Produces
The level gain generator includes a damper control apparatus according to claim 3 or 4 the vibration level and generates a value of less than 1 the level gain becomes a predetermined value or more. A speed correction unit for correcting the low frequency component by multiplying the low frequency component by the level gain;
The damper control device according to claim 5 , wherein the correction gain generation unit generates the correction gain based on the corrected low frequency component.

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