Control device and method for variable damping force damper

Abstract

The invention provides an apparatus and a method for controlling a variable damping force damper. The variable damping force damper is arranged on each wheel of a vehicle. The control device includes: a damping force setting unit that sets a damping force target value generated in each of the variable damping force dampers on the basis of a lateral acceleration, a yaw rate, and a vehicle speed of the vehicle; a drive current setting unit that sets a drive current generated in each variable damping force damper on the basis of the damping force target value; and a turning state determination unit that determines the turning state of the vehicle on the basis of at least one of the lateral acceleration, the steering angle, the yaw rate, and the roll angle. When the turning state determination unit determines that the vehicle is in the initial turning state, the damping force setting unit sets a rear wheel damping force target value of the vehicle to be higher than a front wheel damping force target value of the vehicle. The drive current setting unit starts control of the drive current of the front wheels of the vehicle after starting control of the drive current of the rear wheels of the vehicle.

Description

Technical Field

[0001] The invention relates to a control device and method of a variable damping force damper. Background Art

[0002] Patent document 1 discloses a vehicle suspension device. This vehicle suspension device improves the turning performance of the vehicle without reducing the braking performance during braking and turning. However, although the rolling rigidity of the front wheel side is reduced in the initial stage of turning, the turning performance can be improved, but the handling stability will be reduced.

[0003] Prior art literature

[0004] Patent document 1: Japanese Patent Publication No. 11-147411

[0005] However, in terms of vehicle behavior safety, how to improve turning performance without reducing handling stability during vehicle turning is a problem. Summary of the invention

[0006] This proposal aims to improve turning performance and handling stability in order to solve the above problems. Furthermore, it will further improve traffic safety and contribute to the development of sustainable transportation systems.

[0007] According to an embodiment of the present invention, a variable damping force damper control device is provided. The variable damping force damper is provided at each wheel of a vehicle. The control device comprises: a damping force setting unit, which sets a damping force target value generated in each of the variable damping force dampers based on the lateral acceleration, yaw rate and vehicle speed of the vehicle; a driving current setting unit, which sets a driving current generated in each of the variable damping force dampers based on the damping force target value; and a turning state judgment unit, which judges the turning state of the vehicle based on at least one of the lateral acceleration, steering angle, yaw rate and roll angle. When the turning state judgment unit judges that the vehicle is in the initial state of turning, the damping force target value of the rear wheels of the vehicle is set to be higher than the damping force target value of the front wheels of the vehicle through the damping force setting unit. After starting to control the driving current of the rear wheels of the vehicle, the driving current setting unit starts to control the driving current of the front wheels of the vehicle.

[0008] According to an embodiment of the present invention, in the above-mentioned variable damping force damper control device, when the turning state judgment unit judges that the vehicle is in the initial turning state, the damping force setting unit sets the damping force target value on the turning inner wheel side of the front wheel to be higher than the damping force target value on the turning outer wheel side of the front wheel, and sets the damping force target value on the turning inner wheel side of the rear wheel to be lower than the damping force target value on the turning outer wheel side of the rear wheel.

[0009] According to another embodiment of the present invention, a control method for a variable damping force damper is proposed. The variable damping force damper is arranged on each wheel of a vehicle. The control method comprises: setting a damping force target value generated in each of the variable damping force dampers based on the lateral acceleration, yaw rate and vehicle speed of the vehicle; setting a driving current generated in each of the variable damping force dampers based on the damping force target value; judging the turning state of the vehicle based on at least one of the lateral acceleration, steering angle, yaw rate and roll angle; when judging that the vehicle is in the initial state of turning, setting the damping force target value of the rear wheels of the vehicle to be higher than the damping force target value of the front wheels of the vehicle; and starting to control the driving current of the front wheels of the vehicle after starting to control the driving current of the rear wheels of the vehicle.

[0010] According to an embodiment of the present invention, the above-mentioned control method may also include: when it is judged that the vehicle is in the initial turning state, the damping force target value of the turning inner wheel side of the front wheel is set to be higher than the damping force target value of the turning outer wheel side of the front wheel, and the damping force target value of the turning inner wheel side of the rear wheel is set to be lower than the damping force target value of the turning outer wheel side of the rear wheel.

[0011] According to the above embodiment, the intervention of the mechanical balance control is performed from the rear wheel side, and by delaying the intervention from the front wheel side, it is possible to prevent a decrease in the steering stability due to a decrease in the damping force on the front wheel side. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 4 is a block diagram of a control device of a variable damping force damper according to an embodiment of the present invention.

[0013] Figure 2 A schematic diagram illustrating states of a variable damping force damper control method at various stages during a turn according to an embodiment of the present invention.

[0014] Figure 3 4 is a schematic diagram of a control process scenario of a control device for a variable damping force damper according to an embodiment of the present invention.

[0015] Description of Reference Numerals

[0016] 100: Variable damping force damper control device

[0017] 102: Damping force setting unit

[0018] 104: Driving current setting unit

[0019] 106: Turning state judgment unit

[0020] 108: Vehicle speed sensor

[0021] 110: Control Department

[0022] 130: Variable damping force damper

[0023] 140: Steering device

[0024] 150: Lateral acceleration sensor

[0025] 152: Yaw angle sensor

[0026] 154: Roll angle sensor DETAILED DESCRIPTION

[0027] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0028] Figure 1 is a block diagram of a control device for a variable damping force damper according to an embodiment of the present invention. Figure 1 As shown, the variable damping force damper control device 100 includes at least but not limited to: a damping force setting unit 102, a driving current setting unit 104, a turning state judgment unit 106, a vehicle speed sensor 108 and a control unit 110. The variable damping force damper control device 100 is used to control a variable damping force damper 130 installed in a vehicle suspension device. The control unit 110 can control the damping force setting unit 102, the driving current setting unit 104, the turning state judgment unit 106 and the vehicle speed sensor 108, or work in coordination with them.

[0029] Generally speaking, the variable damping force damper 130 is provided at each wheel of the vehicle. More specifically, the variable damping force damper 130 is provided in a suspension device for mounting each wheel of the vehicle. The variable damping force damper 130 can adjust the damping force of the variable damping force damper 130 in response to various conditions. The variable damping force damper can be electronically controlled, such as being controlled by the control unit 110. The variable damping force damper 130 can automatically switch the damping force according to various driving conditions. The variable damping force damper 130 can change the damping force of the variable damping force damper 130 accordingly by changing the magnitude of the driving current.

[0030] The damping force setting unit 102 sets the damping force target value generated in each of the variable damping force dampers 130 based on the lateral acceleration, the yaw rate and the vehicle speed. That is, the damping force setting unit 102 can dynamically set the damping force target value of the variable damping force damper 130 according to the driving state of the vehicle during the turning process. The driving state of the vehicle can be determined, for example, based on the lateral acceleration, the yaw rate and the vehicle speed, and of course can also be based on other vehicle dynamics parameters, such as the pitch angle, the roll angle, etc.

[0031] Regarding the lateral acceleration, the lateral acceleration of the vehicle refers to the acceleration in the direction perpendicular to the vehicle's driving direction, which is the acceleration caused by the centrifugal force generated when the vehicle turns. That is, the tendency of the vehicle to be "thrown away". The greater the lateral acceleration, the easier it is for the vehicle to be "thrown away" from the driving path. Generally speaking, the lateral acceleration can be detected by a lateral acceleration sensor 150 provided in the vehicle. The lateral acceleration detected by the acceleration sensor 150 can be transmitted to the damping force setting unit 102.

[0032] In addition, the dynamic behavior of the vehicle can be described by the yaw angle (yaw rate), pitch angle (pitch rate) and roll angle (roll rate) of the three axes, which can be detected by the yaw angle (yaw rate) sensor 152, the pitch angle (pitch rate) sensor and the roll angle (roll rate) sensor 154 respectively arranged in the vehicle. By detecting the yaw angle, pitch angle and roll angle, the yaw rate, pitch rate and roll rate of the time-varying rate can be further calculated. Regarding the sensors of these parameter angles, the present invention is not specifically limited, as long as the detection angle and its change rate can be achieved.

[0033] The speed of the vehicle can be detected by the speed sensor 108. The speed sensor 108 is, for example, a sensor disposed near the wheel to detect the rotation speed to obtain the vehicle speed. The vehicle speed can also be detected by various available sensors, such as using a camera to perform image analysis and processing, radar, lidar, and other available technical means, which are not particularly limited in the present invention.

[0034] In addition, the driving current setting unit 104 of the variable damping force damper control device 100 can set the driving current generated in the variable damping force damper 130 provided in each wheel (i.e., the corresponding suspension device) based on the damping force target value set by the damping force setting unit 102. Through this driving current, the damping force of the variable damping force damper 130 can be changed. The driving current setting unit 104 can be implemented by the control unit 110, for example, or it can be an independent functional block.

[0035] The turning state determination unit 106 can determine the turning state of the vehicle based on at least one of the lateral acceleration, steering angle, yaw rate and roll angle. The lateral acceleration, yaw rate and roll angle can be detected by the lateral acceleration sensor 150, the yaw angle sensor 152 and the roll angle sensor 154.

[0036] In addition, regarding the steering angle (stearing angle), for example, it can be determined based on the steering angle (or steering angle) of the steering wheel (steering device 140) in the vehicle. As an example, it can be implemented by a sensor installed on the steering device 140 and the control unit 110. This sensor is used to detect the operating angle of the steering device 140 relative to a reference position to determine whether the vehicle is in a turning state. The reference position can generally be the position where the steering device 140 is in the steering wheel of the vehicle (for example, the left and right wheels in front) so that the vehicle keeps going straight. The operating angle of the steering device 140 detected by the sensor can be processed and analyzed by the control unit 110 to obtain whether the vehicle is in a turning state.

[0037] In addition, the control unit 110 is used to control the vehicle. The control unit 110 can control various behavior modes of the vehicle, such as acceleration, deceleration, parking, avoidance, etc., and can also detect the vehicle state or the state of the surrounding area of ​​the vehicle by controlling various sensors and detectors. For those skilled in the art, the various control methods of the control unit 110 can be designed according to actual needs. The control unit 110 can be implemented by a processor, such as the ECU (Electronic Control Unit) unit of the vehicle. The ECU unit can be used to control various sensors and detectors of the vehicle. Thus, the control unit 110 can receive data, and perform various processing and judgments on the data, and then control various actuating components of the vehicle. Various system controls in the vehicle are controlled by the ECU unit. The control unit 110 can be used to control the above-mentioned parts.

[0038] According to the embodiment of the present invention, when the turning state determination unit 106 determines that the vehicle is in the initial state of turning, that is, when the vehicle turns into a curve, the damping force setting unit 102 sets the target value of the damping force of the rear wheels of the vehicle to be higher than the target value of the damping force of the front wheels of the vehicle. The damping force of the rear wheels of the vehicle will be higher than the damping force of the front wheels. In this way, control is started from the rear wheel side of the vehicle in the initial stage of turning, thereby delaying the reduction of the rolling stiffness of the front wheel side in the initial stage of turning. Therefore, the embodiment of the present invention can suppress the problem of reduced handling stability.

[0039] In addition, as described above, the damping force of the variable damping force damper 130 is changed by the driving current. Therefore, the driving current setting unit 104 can be configured to start controlling the driving current of the front wheels of the vehicle after starting to control the driving current of the rear wheels of the vehicle. In other words, the control device 100 of the variable damping force damper is to preferentially intervene in the damping force control of the rear wheels of the vehicle. Thus, the present invention can prevent the reduction of the handling stability caused by the reduction of the damping force of the front wheels.

[0040] Furthermore, according to the embodiment of the present invention, in order to achieve the above-mentioned mechanical balance control effect, when the turning state determination unit 106 determines that the vehicle is in the initial turning state, the damping force setting unit 102 of the variable damping force damper control device 100 sets the damping force target value of the turning inner wheel side of the front wheel of the vehicle to be higher than the damping force target value of the turning outer wheel side of the front wheel of the vehicle. Furthermore, the damping force setting unit 102 further sets the damping force target value of the turning inner wheel side of the rear wheel of the vehicle to be lower than the damping force target value of the turning outer wheel side of the rear wheel of the vehicle.

[0041] According to the above embodiment, since the damping force on the inner wheel side of the front wheel of the vehicle is greater than the damping force on the outer wheel side, it is possible to prevent the inner wheel side from lifting up when the front wheel of the vehicle is turned while sinking. In addition, in order to prevent the rear wheel side of the vehicle from oversteering, the damping force on the outer wheel side of the rear wheel side is increased relative to the inner wheel side, thereby suppressing the reduction of the handling stability.

[0042] Figure 2 A schematic diagram illustrating states of a variable damping force damper control method at various stages during a turn according to an embodiment of the present invention. Figure 3 4 is a schematic diagram of a control process scenario of a control device for a variable damping force damper according to an embodiment of the present invention.

[0043] like Figure 2 and Figure 3 As shown, the control method of the variable damping force damper 130 of the present invention is performed when the vehicle is driving at a turn. The turning stage can be roughly divided into several scenarios ①, ①', ①", ② and ③ to perform control at each stage. Figure 3 The left-hand curve driving shown is used as an illustrative example, and of course the same control is performed for right-hand curve driving.

[0044] In addition, Table 1 lists examples of damping force changes in scenarios ①, ①', ①", ② and ③ at each stage. In addition, in this example, the damping force in Table 1 is divided into 5 parts, and damping force 3 represents the basic state before the damping force control intervenes. Damping force 1-2 indicates that the damping force is lower than the state of damping force 3, and damping force 4-5 indicates that the damping force is higher than the state of damping force 3. In addition, the higher the number, the higher the damping force. The division stages of the damping force do not have to be 5 parts as in this example, and the designer can set it according to needs. In addition, the damping forces 1-5 can be set within the variable range of the variable damper 130.

[0045] like Figure 2 As shown, axis I represents the behavior of the vehicle (starting from the roll) based on the driver's operation. Axis II represents the period during which the sensor (such as the lateral acceleration sensor 150, the yaw angle sensor 152, the roll angle sensor 154, etc.) detects the vehicle state. In addition, the yaw rate and the lateral acceleration may have a sequence depending on the driving conditions and vehicle settings. Here, only one example is shown. Figure 2 The order shown is not intended to limit the present invention. Figure 2 The roll angle is the last to appear, but according to the vehicle setting, the triggering time point for the start of the damping force control can be set to the yaw rate or the lateral acceleration. That is, if the control unit 110 can set the yaw rate sensor to detect the yaw rate, it can indicate the intervention of the damping force control.

[0046] like Figure 2 , Figure 3 As shown in Table 1, in scenario ①, at time T0, the vehicle V has not yet entered but is about to enter the curve, and the steering angle of the steering device 140 of the vehicle V is 0 degrees. At this time, the damping forces of the four wheels (FL, FR, RL, RR) of the vehicle are first set to the reference state, which is 3 in this example. That is, before the control intervention, the damping forces of the variable damping force dampers 130 corresponding to the four wheels are all set to 3.

[0047] Next, in scenario ①', at time T1, the steering angle of the steering device 140 begins to change, that is, the vehicle V begins to turn (that is, the initial state of turning), and the yaw rate begins to act. At this time, the control of the variable damping force dampers 130 of the four wheels begins to intervene. First, the control of the rear wheels of the vehicle begins to intervene. At this time, the damping force setting unit 102 sets the damping force target value of the rear wheels (RL, RR) of the vehicle V to be higher than the damping force target value of the front wheels (FL, FR) of the vehicle V. That is, from Table 1, the damping force target values ​​of the left front wheel FL and the right front wheel FR are 3 respectively, and the damping force target values ​​of the left rear wheel RL and the right rear wheel RR are 4 and 5 respectively, that is, the rear wheel damping force target value is set to be higher than the front wheel damping force target value of the vehicle V. In addition, the damping force target value 4 of the left rear wheel RL (turning inner wheel side) is lower than the damping force target value 5 of the right rear wheel RR (turning outer wheel side). Thus, by intervening the damping force control from the rear wheel side, it is possible to prevent the right front wheel (FR) side from hunting.

[0048] Next, in scenario ①", at time T2, the steering angle of the steering device 140 further increases, that is, the vehicle V begins to enter the curve, and the lateral acceleration begins to act. At this time, the damping force begins to intervene in the control of the front wheels (FL, FR). At this time, the damping force setting unit 102 still sets the damping force target value of the rear wheels (RL, RR) of the vehicle V to be higher than the damping force target value of the front wheels (FL, FR) of the vehicle V, but the damping force target value of the front wheels begins to decrease from the reference value 3. That is, from Table 1, the damping force target values ​​of the left front wheel FL and the right front wheel FR are 2 and 1 respectively, and the damping force target values ​​of the left rear wheel RL and the right rear wheel RR are still maintained at 4 and 5 respectively, that is, the rear wheel damping force target value is set to be higher than the front wheel damping force target value of the vehicle V.

[0049] At this time, the damping force target value 2 of the left front wheel FL (turning inner wheel side) is higher than the damping force target value 1 of the right front wheel FR (turning outer wheel side), that is, the decrease (3->2) of the damping force target value 2 of the left front wheel FL (turning inner wheel side) is smaller than the decrease (3->1) of the damping force target value 1 of the right front wheel FR (turning outer wheel side). In addition, the damping force target value 4 of the left rear wheel RL (turning inner wheel side) is lower than the damping force target value 5 of the right rear wheel RR (turning outer wheel side).

[0050] The purpose of control at this time is to reduce the damping force target value of the right front wheel FR and make it easier to turn. This is to change the front and rear rolling rigidity. Since the vehicle V is turning while sinking, in order to prevent the inner wheel from lifting, the damping force setting unit 102 sets the damping force target value of the inner wheel side to be greater than the outer wheel side (FL=2>FR=1).

[0051] In scenario ②, at time T3, the roll angle takes effect. Figure 3As shown, the vehicle V is about to travel toward the top of the curve and starts to return to the center. Therefore, the control at this time is aimed at making the behavior of the vehicle V stable.

[0052] At this time, as shown in Table 1, the damping force setting unit 102 begins to reduce the target damping force value of the rear wheels (RL, RR) of the vehicle V (②RL=3<①”RL=4, ②RR=4<①”RR=5), and increases the target damping force value of the rear wheels (RL, RR) (②FL=3>①”FL=2, ②FR=3<①”FR=1). However, basically, the target damping force value of the rear wheels (RL, RR) is still higher than the target damping force value of the front wheels (FL, FR) of the vehicle V.

[0053] In this situation, if the damping force on the front wheel side is reduced or the damping force on the rear wheel side is increased, the load on the front wheel side will increase, thereby preventing understeer.

[0054] Then, if Figure 3 As shown, in scenario ③, at time T4, the vehicle V is basically straightened and is at a position that is almost the apex of the curve. At this time, the damping force setting unit 102 starts to set the damping force target values ​​of the front wheels (FL, FR) and the rear wheels (RL, RR) of the vehicle V as the reference state, that is, the damping force target value is 3. At this point, the control of the damping force of the four wheels of the vehicle V is ended.

[0055] If Figure 3 As shown in FIG. 3 , after scenario ③, when the road continues to bend to the left, the vehicle V will continue to travel on the left-turning curve. At this time, the damping force setting unit 102 of the vehicle V continues the damping force target value control of the above-mentioned stages.

[0056] In summary, in the mechanical balance control of the vehicle V, the right front wheel FR is easy to roll, while the right rear wheel RR is not easy to roll, so the control is to improve the responsiveness at the beginning of the turn. Therefore, the present invention can output a fixed control value and wait for the suspension device to roll in the area without stroke.

[0057] In addition, since the right front wheel FR is prone to roll, the damping force will decrease, resulting in reduced handling stability. Therefore, since it is related to reduced handling stability, it is better to minimize the intervention of damping force control. In addition, the control method detects the driver's intention to steer (operate) the steering device 140, intervenes the control from the rear wheels, and starts the control intervention of the front wheels at an appropriate triggering timing, so that the reduction of handling stability can be suppressed to the minimum.

[0058] [Table 1]

[0059] FL(left front wheel) FR(right front wheel) RL(left rear wheel) RR (Right rear wheel) Scenario ① 3 3 3 3 Situation ①' 3 3 4 5 "Scenario ①" 2 1 4 5 Scenario ② 3 2 3 4 Scenario 3 3 3 3 3

[0060] According to the above embodiment, the intervention of the mechanical balance control is performed from the rear wheel side, and by delaying the intervention from the front wheel side, it is possible to prevent a decrease in the steering stability due to a decrease in the damping force on the front wheel side.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A variable damping force damper control device, wherein the variable damping force damper is arranged on each wheel of a vehicle, characterized in that: include: a damping force setting section that sets a damping force target value generated in each of the variable damping force dampers based on a lateral acceleration, a yaw rate, and a vehicle speed of the vehicle; a driving current setting section that sets a driving current generated in each of the variable damping force dampers based on the damping force target value; and a turning state determination unit for determining a turning state of the vehicle based on at least one of the lateral acceleration, the steering angle, the yaw rate, and the roll angle, When the turning state determination unit determines that the vehicle is in the initial turning state, the damping force setting unit sets the target damping force value of the rear wheels of the vehicle to be higher than the target damping force value of the front wheels of the vehicle. The drive current setting unit starts controlling the drive current of the front wheels of the vehicle after starting controlling the drive current of the rear wheels of the vehicle.

2. The variable damping force damper control device according to claim 1, characterized in that: When the turning state judgment unit determines that the vehicle is in the turning initial state, the damping force setting unit sets the damping force target value on the turning inner wheel side of the front wheel to be higher than the damping force target value on the turning outer wheel side of the front wheel, and sets the damping force target value on the turning inner wheel side of the rear wheel to be lower than the damping force target value on the turning outer wheel side of the rear wheel.

3. A control method for a variable damping force damper, wherein the variable damping force damper is provided on each wheel of a vehicle, characterized in that: include: setting a target value of a damping force generated in each of the variable damping force dampers based on a lateral acceleration, a yaw rate, and a vehicle speed of the vehicle; setting a driving current generated in each of the variable damping force dampers based on the damping force target value; determining a turning state of the vehicle based on at least one of the lateral acceleration, the steering angle, the yaw rate, and the roll angle; When it is determined that the vehicle is in an initial state of turning, setting a target value of the damping force of the rear wheels of the vehicle to be higher than a target value of the damping force of the front wheels of the vehicle; and After starting the control of the drive current of the rear wheels of the vehicle, starting the control of the drive current of the front wheels of the vehicle.

4. The control method of the variable damping force damper according to claim 3, characterized in that: Also includes: When it is determined that the vehicle is in the initial turning state, the damping force target value on the turning inner wheel side of the front wheel is set higher than the damping force target value on the turning outer wheel side of the front wheel, and the damping force target value on the turning inner wheel side of the rear wheel is set lower than the damping force target value on the turning outer wheel side of the rear wheel.

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