Suspension control system and method for vehicle

Abstract

A suspension control system and method for a vehicle are disclosed in which a camera having an electronically controlled suspension system for road pre-determination captures a road surface condition of a road ahead of the vehicle, a suspension controller determines the road surface condition of the road based on information of the captured camera, and a suspension controller controls the semi-active suspension to be in an ON state or an OFF state based on road surface condition determination information transmitted from the suspension controller and a value detected by a wheel acceleration sensor suspended on a wheel of the vehicle, thereby improving not only NVH performance but also NVH performance. And the driving vibration damping performance depending on the road surface condition is improved.

Description

Technical Field

[0001] The present disclosure relates to a mount control system and method for a vehicle. More specifically, the present invention relates to a mount control system and method for a vehicle, which can improve driving vibration through damping control of the mount using a configuration of an electronically controlled suspension system with road anticipation. Background Art

[0002] An electronically controlled suspension system with road prediction refers to a system that detects the road condition of a road ahead of a vehicle during vehicle travel and performs damping control of the suspension according to the detected road condition.

[0003] To this end, an electronically controlled suspension system with road prediction includes a camera suspended on the front of the vehicle (the inner upper end of the windshield), a suspension controller configured to determine the road surface condition of the road based on the camera's shooting information, and a suspension configured to control its damping according to the road surface condition determined by the suspension controller.

[0004] Therefore, during vehicle driving, the road condition of the road in front of the vehicle (such as potholes, bumps, and road roughness on the road) is detected by a camera, the road condition is determined by a suspension controller based on the information captured by the camera, and independent damping control of the suspension of the corresponding wheels is performed according to the determined road condition. Impacts that depend on the road condition can be attenuated without transmitting the impact to passengers in the vehicle.

[0005] A powertrain of a vehicle including an engine and a transmission is supported by a plurality of mounts so as to be suspended on a vehicle body, and a drive motor for an electric vehicle is supported by a plurality of mounts (which distribute loads and have controllable behaviors) so as to be suspended on a vehicle body.

[0006] Semi-active mounts are used as these mounts, which are hydraulic mounts having adjustable dynamic characteristics.

[0007] To this end, the semi-active mount includes an actuator configured to open and close a bypass flow path for the fluid, and the actuator can be controlled to be opened or closed by a mount controller.

[0008] In this case, turning on the semi-active mount indicates turning on the actuator of the semi-active mount, and turning off the semi-active mount indicates turning off the actuator of the semi-active mount.

[0009] Therefore, the dynamic characteristics of the semi-active suspension can be adjusted by turning the actuators of the semi-active suspension on or off by the suspension controller.

[0010] For example, when the semi-active suspension is controlled to be turned on (operating), the dynamic stiffness of the suspension can be adjusted to be less than a specified low level in the full frequency band, and thus the noise, vibration and harshness performance is improved, that is, the idle vibration and roaring noise transmitted to the interior of the vehicle are reduced, but even in the beating frequency band which is the main excitation source of the road vibration, the dynamic stiffness and damping force of the suspension are adjusted to be less than a specified level, and thus the driving vibration damping effect depending on the road condition is poor, such as Figure 1 shown.

[0011] On the other hand, when the semi-active suspension is controlled to be closed (not in operation), the dynamic stiffness and damping force of the suspension are adjusted to be equal to or greater than a specified level in the hopping frequency band which is the main excitation source of road vibration, so the driving vibration damping effect is large, but the noise, vibration and harshness performance is poor, that is, the isolation or reduction effect of idling vibration and roaring noise is poor, such as Figure 2 shown.

[0012] Thus, the conventional semi-active suspension has a trade-off between the ride vibration damping performance and the NVH performance depending on the on control or the off control.

[0013] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore the above information may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0014] The present disclosure has been devoted to solving the above-mentioned problems associated with the prior art, and an object of the present disclosure is to provide a suspension control system and method for a vehicle, wherein a camera of an electronically controlled suspension system with road prediction captures a road condition of a road ahead of the vehicle, a suspension controller determines the road condition of the road based on the information captured by the camera, and the suspension controller controls the semi-active suspension to be in an open state or a closed state based on the road condition determination information transmitted from the suspension controller and a value detected by a wheel acceleration sensor installed on a wheel of the vehicle, thereby improving not only the NVH performance but also the riding vibration damping performance depending on the road condition.

[0015] On the one hand, the present disclosure provides a suspension control system for a vehicle, comprising: a camera configured to photograph a road surface condition of a road in front of the vehicle; a wheel acceleration sensor mounted on a front wheel of the vehicle and configured to detect a vertical acceleration acting on the front wheel; a suspension controller configured to determine a road surface condition of the road based on photographing information from the camera and a value detected by the wheel acceleration sensor, and a suspension controller configured to control a semi-active suspension to an open state or a closed state based on road surface condition determination information transmitted from the suspension controller and a value detected by the wheel acceleration sensor.

[0016] In a preferred embodiment, the suspension controller can determine the road condition of the road as one of a normal road condition, a rough road condition and a bumpy road condition, and when the road roughness value of the road is less than a reference value, the suspension controller can determine the road condition of the road as a normal road condition, and when the road roughness value of the road is equal to or greater than another reference value, the road condition of the road can be determined as a rough road condition.

[0017] In another preferred embodiment, the suspension controller may determine the road surface condition of the road as a bumpy road surface condition when there is a bump within a set distance in front of the vehicle or when the vehicle passes over a bump.

[0018] In another preferred embodiment, in a case where the road condition of the road transmitted from the suspension controller is determined to be a normal road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than another reference value, the suspension controller can control the semi-active suspension from an open state to a closed state.

[0019] In another preferred embodiment, after controlling the semi-active suspension to enter the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the reference value for a first reference time, the suspension controller may control the semi-active suspension to return from the closed state to the open state.

[0020] In another preferred embodiment, after controlling the semi-active suspension to return from the closed state to the open state, when the value detected by the wheel acceleration sensor becomes equal to or greater than the reference value again within a second reference time longer than the first reference time, the suspension controller can control the semi-active suspension to re-enter the closed state from the open state.

[0021] In another preferred embodiment, after the actuator controlling the semi-active suspension re-enters the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the reference value for a third reference time that is longer than the first reference time but shorter than the second reference time, the suspension controller can control the semi-active suspension to return from the closed state to the open state again.

[0022] In another further preferred embodiment, when it is determined that the road condition transmitted from the suspension controller is a rough road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than the value obtained by multiplying another reference value by the rough road weight, the suspension controller can control the semi-active suspension from the open state to the closed state.

[0023] In a further preferred embodiment, after controlling the semi-active suspension to enter the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the value obtained by multiplying the reference value by the rough road weight for a first reference time, the suspension controller may control the semi-active suspension to return from the closed state to the open state.

[0024] In a further preferred embodiment, after controlling the semi-active suspension to return from the closed state to the open state, when the value detected by the wheel acceleration sensor is again equal to or greater than the value obtained by multiplying the reference value by the rough road weight within a second reference time longer than the first reference time, the suspension controller can control the semi-active suspension to re-enter the closed state from the open state.

[0025] In a further preferred embodiment, after controlling the actuator of the semi-active suspension to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor is less than the value obtained by multiplying the reference value by the rough road weight for a third reference time that is longer than the first reference time but shorter than the second reference time, the suspension controller can control the semi-active suspension to return from the closed state to the open state again.

[0026] In another preferred embodiment, when it is determined that the road condition transmitted from the suspension controller is a bumpy road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than the value obtained by multiplying another reference value by the bump weight, the suspension controller can control the semi-active suspension from an open state to a closed state.

[0027] In a further preferred embodiment, after controlling the semi-active suspension to enter the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the value obtained by multiplying the reference value by the bump weight for a first reference time, the suspension controller may control the semi-active suspension to return from the closed state to the open state.

[0028] In another preferred embodiment, after controlling the semi-active suspension to return from the closed state to the open state, when the value detected by the wheel acceleration sensor becomes equal to or greater than the value obtained by multiplying the reference value by the bump weight within a second reference time longer than the first reference time, the suspension controller can control the semi-active suspension to re-enter the closed state from the open state.

[0029] In another preferred embodiment, after the actuator controlling the semi-active suspension re-enters the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the value obtained by multiplying the reference value by the bump weight for a third reference time that is longer than the first reference time but shorter than the second reference time, the suspension controller can control the semi-active suspension to return from the closed state to the open state again.

[0030] In another aspect, the present disclosure provides a suspension control method for a vehicle, comprising: photographing a road condition of a road in front of the vehicle by a camera; detecting a vertical acceleration acting on the front wheel by a wheel acceleration sensor installed on the front wheel of the vehicle; determining a road condition of the road by a suspension controller based on the photographing information of the camera and a value detected by the wheel acceleration sensor; and controlling a semi-active suspension to an open state or a closed state by a suspension controller based on road condition determination information transmitted from the suspension controller and a value detected by the wheel acceleration sensor.

[0031] In a preferred embodiment, when the road condition of a road is determined by a suspension controller as one of a normal road condition, a rough road condition, and a bumpy road condition, when the road roughness value of the road is less than a reference value, the road condition of the road can be determined as a normal road condition; when the road roughness value of the road is equal to or greater than another reference value, it can be determined as a rough road condition; when there is a bump within a set distance in front of the vehicle or when the vehicle passes over a bump, it can be determined as a bumpy road condition.

[0032] In another preferred embodiment, when the road condition of the road transmitted from the suspension controller is determined to be a normal road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than another reference value, the semi-active suspension can be controlled from an open state to a closed state by the suspension controller.

[0033] In another preferred embodiment, when it is determined that the road condition transmitted from the suspension controller is a normal road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than the value obtained by multiplying another reference value by the rough road weight, the semi-active suspension can be controlled by the suspension controller to enter a closed state from an open state.

[0034] In another preferred embodiment, when it is determined that the road condition transmitted from the suspension controller is a normal road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than the value obtained by multiplying another reference value by the bump weight, the semi-active suspension can be controlled from the open state to the closed state by the suspension controller.

[0035] Other aspects and preferred embodiments of the disclosure are discussed below.

[0036] The above and other features of the present disclosure are discussed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above-mentioned and other features of the present disclosure will now be described in detail with reference to certain exemplary embodiments of the invention shown in the accompanying drawings, hereinafter given by way of illustration only and therefore not limiting of the present disclosure, and wherein:

[0038] Figure 1 is a graph showing the dynamic stiffness of the semi-active mount in the on state;

[0039] Figure 2 is a graph representing the dynamic stiffness of the semi-active mount in a closed state;

[0040] Figure 3 is a schematic diagram showing a suspension control system for a vehicle according to the present disclosure;

[0041] Figure 4 is a schematic diagram showing a suspension control system for a vehicle according to the present disclosure;

[0042] Figure 5 is a flow chart representing a suspension control method for a vehicle according to the present disclosure;

[0043] Figure 6 is a flow chart representing a suspension control method for a vehicle according to the present disclosure;

[0044] Figure 7 is a flow chart representing a suspension control method for a vehicle according to the present disclosure;

[0045] Figure 8A test result graph showing improvement in vertical vibration of a vehicle body when a semi-active suspension is controlled from an open state to a closed state based on a suspension control system and method according to the present disclosure is shown;

[0046] Fig. 9 shows a test result graph indicating improvement in vertical vibration of a vehicle body and a powertrain when a semi-active suspension is controlled from an open state to a closed state during driving of a vehicle on Belgian roads based on a suspension control system and method according to the present disclosure; and

[0047] Fig.10 A graph of test results showing improvement in vertical vibration of a vehicle body and a powertrain is shown, where a semi-active suspension is controlled from an on state to a off state during driving a vehicle on a concrete road based on a suspension control system and method according to the present disclosure.

[0048] It should be understood that the accompanying drawings are not necessarily drawn to scale, and that they present a somewhat simplified representation of various preferred features illustrating the basic principles of the present disclosure. The specific design features of the present disclosure as disclosed herein (including, for example, specific dimensions, orientations, locations, and shapes) will be determined in part by the specific intended application and use environment.

[0049] In the drawings, reference numbers refer to the same or equivalent parts of the present disclosure throughout the several figures of the drawing. DETAILED DESCRIPTION

[0050] The specific structure or function description in the embodiments of the present disclosure set forth in the following description will be given exemplarily to describe the embodiments of the present disclosure, and the present disclosure can be embodied in many replaceable forms. In addition, it should be understood that the present disclosure should not be interpreted as being limited to the embodiments set forth herein, and the embodiments of the present disclosure are only provided to fully disclose the present disclosure and cover modifications, equivalents or replacements that fall within the scope and technical scope of the present disclosure.

[0051] In the following description of the embodiments, terms such as "first" and "second" are used only to describe various elements, and these elements should not be interpreted as being limited by these terms. These terms are used only to distinguish one element from other elements. For example, without departing from the scope of the present disclosure, a first element described below may be referred to as a second element, and similarly, a second element described below may be referred to as a first element.

[0052] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0053] Figure 3 and Figure 4 is a schematic diagram showing a suspension control system for a vehicle according to the present disclosure.

[0054] Reference Figure 3 , an electronically controlled suspension system with road prediction, comprising: a camera mounted on the front of a vehicle (the inner upper end of a windshield); and a suspension controller configured to determine a road surface condition based on the camera's photographic information and to perform damping control of the suspension according to the determined road surface condition.

[0055] The present disclosure focuses on adjusting the dynamic stiffness of a semi-active suspension and the damping amount of the suspension relative to driving vibrations depending on road conditions through cooperative control between a suspension controller of an electronically controlled suspension system with road anticipation and a suspension controller configured to control the semi-active suspension so as to be turned on or off.

[0056] For this reason, Figure 3 and Figure 4 As shown, a suspension control system for a vehicle according to the present disclosure may include: a camera 10, configured to photograph a road surface condition of a road in front of the vehicle; a wheel acceleration sensor 20, mounted on the front wheel of the vehicle or at a position around the front wheel to detect a vertical acceleration acting on the front wheel; a suspension controller 30, configured to determine a road surface condition of the road based on photographing information of the camera 10 and a value detected by the wheel acceleration sensor 20, and a suspension controller 40, which controls a semi-active suspension 50 to be turned on or off based on road surface condition determination information transmitted from the suspension controller 30 and a value detected by the wheel acceleration sensor 20.

[0057] The suspension controller 30 is configured to determine the road surface condition of the road as one of a normal road surface condition, a rough road surface condition, and a bumpy road surface condition based on the photographing information of the camera 10 and the value detected by the wheel acceleration sensor 20 .

[0058] Specifically, when the road surface roughness value (RRV) of the road is less than the reference value prvG, the suspension controller 30 determines the road surface condition as a normal road surface condition; when the road surface roughness value (RRV) of the road is equal to or greater than the reference value prvF, the suspension controller 30 determines the road surface condition as a rough road surface condition.

[0059] For example, the road roughness value (RRV) may be an index value calculated by integrating the value detected by the wheel acceleration sensor 20, the reference value prvF may be a parameter value for determining the road condition as a rough road condition and activating the rough road mode, which may be set to 5, and the reference value prvG may be a parameter value for determining the road condition as a normal road condition and deactivating the rough road mode, which may be set to 3.

[0060] In addition, the value detected by the wheel acceleration sensor 20 is a vertical acceleration value acting on the wheel, and increases as the road surface roughness increases, and decreases as the road surface roughness decreases. Therefore, the road surface roughness value can be obtained as an index value calculated by integrating the value detected by the wheel acceleration sensor 20.

[0061] Furthermore, the suspension controller 30 determines the road surface condition as a bumpy road surface condition when there is a bump within a set distance (eg, 20 m) in front of the vehicle or when the vehicle passes over a bump based on the photographing information of the camera 10 .

[0062] Specifically, the suspension controller 30 identifies the road surface condition information of the road determined based on the shooting information of the camera 10 (i.e., the road surface condition shooting information) as a number. Here, the identification value 0 means that the road surface condition of the road is a normal road surface condition, the identification value 2 means that there is a bump within 20m in front of the vehicle, and the identification value 3 means that the vehicle passes the bump. When the identification value is equal to or greater than the reference value prvE, the suspension controller 30 can determine that the road surface condition of the road is a bumpy road surface condition.

[0063] For example, the reference value prvE may be a value for determining that the road surface condition is a bumpy road surface condition, and the value may be set to 2.

[0064] Information on the road surface condition of the road determined as one of the normal road surface condition, the rough road surface condition and the bumpy road surface condition by the suspension controller 30 as described above is transmitted to the suspension controller 40 and used to perform the opening or closing control of the semi-active suspension 50 .

[0065] According to one embodiment, when the road surface condition of the road transmitted from the suspension controller 30 is determined to be a normal road surface condition, when the detection value detected by the wheel acceleration sensor 20 installed on the left front wheel or the right front wheel is equal to or greater than the reference value prvA, the suspension controller 40 controls the actuator of the semi-active suspension 50 from the open state to the closed state, thereby entering aftershock control (driving vibration damping control).

[0066] For example, the reference value prvA may be a value used to determine whether the actuator enters the running vibration damping control or releases the running vibration damping control, and may be set to 1.95 g.

[0067] After controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the reference value prvA for a first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state to improve the NVH performance, that is, to reduce the idle vibration and roaring noise.

[0068] For example, the first reference time prvB may be set to 1 second.

[0069] In addition, after the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, when the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the reference value prvA again within the second reference time prvC which is longer than the first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to re-enter the closed state from the open state to re-enter the aftershock control (driving vibration damping control).

[0070] For example, the second reference time prvC may be set to be 6 seconds longer than the first reference time prvB in order to suppress the actuator of the semi-active mount 50 from frequently re-entering the closed state from the open state.

[0071] In addition, after controlling the actuator of the semi-active suspension 50 to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes less than the reference value prvA for a third reference time prvB+prvD that is longer than the first reference time prvB but shorter than the second reference time prvC, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state again to improve the NVH performance, that is, to reduce the idle vibration and roaring noise.

[0072] For example, the actuator of the semi-active suspension 50 re-enters the closed state from the open state is considered to be a situation requiring repeated aftershock control, so the third reference time prvB+prvD can be set to 3 seconds, which is longer than the first reference time prvB but shorter than the second reference time prvC.

[0073] According to another embodiment, when the road surface condition transmitted from the suspension controller 30 is determined to be a rough road surface condition, when the value detected by the wheel acceleration sensor 20 installed on the left front wheel or the right front wheel is equal to or greater than the value obtained by multiplying the reference value prvA by the rough road surface weight prvH, the suspension controller 40 controls the actuator of the semi-active suspension 50 from the open state to the closed state, thereby entering aftershock control (driving vibration damping control).

[0074] For example, the reference value prvA can be a value used to determine whether the actuator enters the driving vibration damping control or releases the driving vibration damping control, which can be set to 1.95g, and the rough road weight prvH can be a value used to reduce the reference value prvA, and the rough road weight prvH can be set to 0.8 so that aftershock control (driving vibration damping control) can be performed more easily compared with normal road conditions.

[0075] After controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the rough road weight prvH for a first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state to improve the NVH performance, that is, to reduce the idle vibration and the roaring noise.

[0076] For example, the first reference time prvB may be set to 1 second.

[0077] In addition, after the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, when the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the value obtained by multiplying the reference value prvA by the rough road weight prvH within the second reference time prvC longer than the first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to re-enter the closed state from the open state so as to re-enter the aftershock control (driving vibration damping control).

[0078] For example, the second reference time prvC may be set to be 6 seconds longer than the first reference time prvB in order to suppress the actuator of the semi-active mount 50 from frequently re-entering the closed state from the open state.

[0079] In addition, after controlling the actuator of the semi-active suspension 50 to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 is less than the value obtained by multiplying the reference value prvA by the rough road weight prvH for a third reference time prvB+prvD that is longer than the first reference time prvB but shorter than the second reference time prvC, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state again to improve the NVH performance, that is, to reduce idle vibration and roaring noise.

[0080] For example, the actuator of the semi-active suspension 50 re-enters the closed state from the open state is considered to be a situation requiring repeated aftershock control, so the third reference time prvB+prvD can be set to 3 seconds, which is longer than the first reference time prvB but shorter than the second reference time prvC.

[0081] According to another embodiment, when the road surface condition of the road transmitted from the suspension controller 30 is determined to be a bumpy road surface condition, when the value detected by the wheel acceleration sensor 20 installed on the left front wheel or the right front wheel is equal to or greater than the value obtained by multiplying the reference value prvA by the collision weight prvL, the suspension controller 40 controls the actuator of the semi-active suspension 50 from the open state to the closed state, thereby entering aftershock control (driving vibration damping control).

[0082] For example, the reference value prvA can be a value used to determine whether the actuator enters the driving vibration damping control or releases the driving vibration damping control, which can be set to 1.95g, and the bump weight prvL can be a value used to significantly reduce the reference value prvA, which can be set to 0.2, so that aftershock control (driving vibration damping control) can be performed more easily compared with normal road conditions and rough road conditions.

[0083] After controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the bump weight prvL for a first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state to improve the NVH performance, that is, to reduce the idle vibration and roaring noise.

[0084] For example, the first reference time prvB may be set to 1 second.

[0085] In addition, after the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, when the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the value obtained by multiplying the reference value prvA by the bump weight prvL within the second reference time prvC which is longer than the first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to re-enter the closed state from the open state to re-enter the aftershock control (driving vibration damping control).

[0086] For example, the second reference time prvC may be set to be 6 seconds longer than the first reference time prvB in order to suppress the actuator of the semi-active mount 50 from frequently re-entering the closed state from the open state.

[0087] In addition, after controlling the actuator of the semi-active suspension 50 to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes less than the value obtained by multiplying the reference value prvA by the bump weight prvL for a third reference time prvB+prvD (which is longer than the first reference time prvB but shorter than the second reference time prvC), the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state again to improve the NVH performance, that is, to reduce idle vibration and roaring noise.

[0088] For example, the actuator of the semi-active suspension 50 re-enters the closed state from the open state is considered to be a situation requiring repeated aftershock control, so the third reference time prvB+prvD can be set to 3 seconds, which is longer than the first reference time prvB but shorter than the second reference time prvC.

[0089] Hereinafter, a suspension control method for a vehicle according to one embodiment of the present disclosure performed based on the above-mentioned configuration will be described as follows.

[0090] Figure 5 is a flowchart representing a suspension control method for a vehicle when it is determined that the road surface condition of the road is a normal road surface condition.

[0091] First, it is determined whether an opening control condition or a closing control condition of the semi-active mount 50 is satisfied during vehicle driving ( S101 ).

[0092] For example, when the suspension controller 30 and the suspension controller 40 receive a signal from the engine controller indicating that the engine speed is 1200RPM-1600RPM and receive a signal from the accelerator pedal position sensor indicating that the depression amount of the accelerator pedal is 10%-90% in the starting state of the vehicle, it can be determined that the conditions for controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state or from the closed state to the open state are met.

[0093] Therefore, when it is determined that the opening or closing control conditions of the semi-active suspension 50 are met, the camera 10 can capture the road surface condition of the road in front of the vehicle, and the wheel acceleration sensor 20 installed on the front wheel of the vehicle can detect the vertical acceleration acting on the front wheel.

[0094] Thereafter, the suspension controller 30 may determine that the road surface condition of the road is a normal road surface condition based on the photographing information of the camera 10 and the value detected by the wheel acceleration sensor 20 ( S102 ).

[0095] For example, when the road surface roughness value (RRV) of the road based on the value detected by the wheel acceleration sensor 20 is less than the reference value prvG, the suspension controller 30 can determine the road surface condition of the road as a normal road surface condition, and the suspension controller 30 can identify the information about the road surface condition of the road determined based on the shooting information of the camera 10 as a number, and when the identification value is 0, the road surface condition of the road can be determined as a normal road surface condition.

[0096] Thereafter, when the road surface condition transmitted from the suspension controller 30 is determined to be a normal road surface condition, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 installed on the left front wheel or the right front wheel is equal to or greater than a reference value prvA (S103).

[0097] As a result of the determination, when the value detected by the wheel acceleration sensor 20 is equal to or greater than the reference value prvA, the suspension controller 40 controls the actuator of the semi-active suspension 50 to enter the closed state from the open state, thereby entering the aftershock control (travel vibration damping control) (S104).

[0098] Specifically, when the vertical acceleration acting on the front wheel (i.e., the value detected by the wheel acceleration sensor 20 is greater than the reference value prvA), the suspension controller 40 determines the road surface condition as a normal road surface condition, but identifies the road surface as an uneven normal road surface that generates driving vibration and therefore requires aftershock control (driving vibration damping control), thereby controlling the actuator of the semi-active suspension 50 from an open state to a closed state.

[0099] like Figure 2 As shown, when the actuator controlling the semi-active suspension 50 enters a closed state, the dynamic stiffness and damping force of the semi-active suspension 50 can be adjusted to be equal to or greater than a specified level in the bounce frequency band which is the main excitation source of road vibration, and thus riding vibration damping by the semi-active suspension 50 can be achieved.

[0100] Thereafter, the suspension controller 40 determines whether a condition for controlling the actuator of the semi-active suspension to return to the open state is satisfied ( S105 ).

[0101] That is, after controlling the actuator of the semi-active mount 50 to enter the closed state from the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 is less than the reference value prvA for the first reference time prvB.

[0102] After controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the reference value prvA for a first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state (S106).

[0103] When the actuator of the semi-active suspension 50 is controlled to return from the closed state to the open state, the dynamic stiffness of the semi-active suspension 50 can be adjusted to be less than a specified low level in the full frequency band, such as Figure 1 As shown, improvements in NVH performance, such as reduction in idle vibration and roar noise transmitted to the vehicle interior, can be achieved.

[0104] Thereafter, after the actuator controlling the semi-active mount 50 returns from the closed state to the open state, the suspension controller 40 determines whether a condition for the actuator controlling the semi-active mount 50 to re-enter the closed state from the open state is satisfied within the second reference time prvC.

[0105] That is, after the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the reference value prvA again within the second reference time prvC longer than the first reference time prvB (S107).

[0106] After controlling the actuator of the semi-active suspension 50 to return from the closed state to the open state, when the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the reference value prvA again within the second reference time prvC longer than the first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to re-enter the closed state from the open state (S108).

[0107] Here, the second reference time prvC may be set to be 6 seconds longer than the first reference time prvB in order to suppress the actuator of the semi-active mount 50 from frequently re-entering the closed state from the open state.

[0108] like Figure 2 As shown, when the actuator of the semi-active suspension 50 is controlled to re-enter the closed state, the dynamic stiffness and damping force of the semi-active suspension 50 can be adjusted to be equal to or greater than a specified level in the bounce frequency band which is the main excitation source of road vibration, and thus riding vibration damping by the semi-active suspension 50 can be achieved.

[0109] Thereafter, after the actuator controlling the semi-active mount 50 reenters the closed state from the open state, the suspension controller 40 determines whether a condition for the actuator controlling the semi-active mount 50 to return from the closed state to the open state again is satisfied.

[0110] That is, after the actuator controlling the semi-active suspension 50 re-enters the closed state from the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes smaller than the reference value prvA for a third reference time prvB+prvD, which is longer than the first reference time prvB but shorter than the second reference time prvC (S109).

[0111] After controlling the actuator of the semi-active suspension 50 to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 is less than the reference value prvA for a third reference time prvB+prvD (the third reference time prvB+prvD is longer than the first reference time prvB but shorter than the second reference time prvC), the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state again (S110).

[0112] Here, the actuator of the semi-active suspension 50 re-enters the closed state from the open state as considered to be a situation requiring repeated aftershock control, and therefore, the third reference time prvB+prvD may be set to 3 seconds, which is longer than the first reference time prvB but shorter than the second reference time prvC.

[0113] When the actuator controlling the semi-active suspension 50 returns from the closed state to the open state again, the dynamic stiffness of the semi-active suspension 50 can be adjusted to be less than a specified low level in the full frequency band, such as Figure 1 As shown, improvements in NVH performance, such as reduction in idle vibration and roar noise transmitted to the vehicle interior, can be achieved.

[0114] Hereinafter, a suspension control method of a vehicle according to another embodiment of the present disclosure performed based on the above-mentioned configuration will be described as follows.

[0115] Figure 6 is a flow chart representing a suspension control method for a vehicle when it is determined that a road surface condition is a rough road surface condition.

[0116] First, it is determined whether an opening or closing control condition of the semi-active mount 50 is satisfied during vehicle driving ( S201 ).

[0117] For example, when the vehicle is in the starting state, the suspension controller 30 and the suspension controller 40 receive a signal from the engine controller indicating that the engine speed is 1200RPM1600 RPM and receive a signal from the accelerator pedal position sensor indicating that the depression amount of the accelerator pedal is 10%-90%, it can be determined that the conditions for controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state or from the closed state to the open state are met.

[0118] Therefore, when it is determined that the opening or closing control conditions of the semi-active suspension 50 are met, the camera 10 can capture the road surface condition of the road in front of the vehicle, and the wheel acceleration sensor 20 installed on the front wheel of the vehicle can detect the vertical acceleration acting on the front wheel.

[0119] Thereafter, the suspension controller 30 may determine that the road surface condition of the road is a rough road surface condition based on the photographing information of the camera 10 and the value detected by the wheel acceleration sensor 20 ( S202 ).

[0120] For example, when the road roughness value (RRV) of the road is equal to or greater than the reference value prvF based on the value detected by the wheel acceleration sensor 20, the suspension controller 30 may determine the road surface condition of the road as the rough road surface condition.

[0121] Thereafter, when the road surface condition transmitted from the suspension controller 30 is determined to be a rough road surface condition, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 installed on the left front wheel or the right front wheel is equal to or greater than the value obtained by multiplying the reference value prvA by the rough road surface weight prvH (S203).

[0122] As a result of the determination, when the value detected by the wheel acceleration sensor 20 is equal to or greater than the value obtained by multiplying the reference value prvA by the rough road weight prvH, the suspension controller 40 controls the actuator of the semi-active suspension 50 from the open state to the closed state, thereby entering the aftershock control (driving vibration damping control) (S204).

[0123] Specifically, when the vertical acceleration acting on the front wheel (i.e., the value detected by the wheel acceleration sensor 20) is equal to or greater than the value obtained by multiplying the reference value prvA by the rough road weight prvH, the suspension controller 40 determines the road surface condition of the road as a rough road surface condition requiring aftershock control (driving vibration damping control), thereby controlling the actuator of the semi-active suspension 50 from the open state to the closed state.

[0124] Here, the rough road weight prvH may be set to 0.8, which is a value that reduces the reference value prvA, so that aftershock control (travel vibration damping control) is easier to perform compared with a normal road condition.

[0125] like Figure 2 As shown, when the actuator of the semi-active suspension 50 is controlled to enter a closed state according to the rough road condition in order to perform aftershock control (driving vibration damping control), the dynamic stiffness and damping force of the semi-active suspension 50 can be adjusted to be equal to or greater than a specified level in the bouncing frequency band which is the main excitation source of road vibration, and thus driving vibration damping can be achieved through the semi-active suspension 50.

[0126] Thereafter, the suspension controller 40 determines whether a condition for controlling the actuator of the semi-active suspension 50 to return to the open state is satisfied ( S205 ).

[0127] That is, after the actuator controlling the semi-active mount 50 enters the closed state from the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the rough road weight prvH for the first reference time prvB.

[0128] After controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the rough road weight prvH for a first reference time prvB, the suspension controller 40 restores the actuator of the semi-active suspension 50 from the closed state to the open state (S206).

[0129] When the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, the dynamic stiffness of the semi-active suspension 50 can be adjusted to be less than a specified low level in the full frequency band, such as Figure 1 As shown, improvements in NVH performance, such as reduction in idle vibration and roar noise transmitted to the vehicle interior, can be achieved.

[0130] Thereafter, after the actuator controlling the semi-active mount 50 returns from the closed state to the open state, the suspension controller 40 determines whether a condition for the actuator controlling the semi-active mount 50 to re-enter the closed state from the open state is satisfied within the second reference time prvC.

[0131] That is, after the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the value obtained by multiplying the reference value prvA by the rough road surface weight prvH again within the second reference time prvC which is longer than the first reference time prvB (S207).

[0132] After controlling the actuator of the semi-active suspension 50 to return to the open state from the closed state, when the value detected by the wheel acceleration sensor 20 again becomes equal to or greater than the value obtained by multiplying the reference value prvA by the rough road weight prvH within the second reference time prvC longer than the first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to re-enter the closed state from the open state (S208).

[0133] Here, the second reference time prvC may be set to be 6 seconds longer than the first reference time prvB in order to suppress the actuator of the semi-active mount 50 from frequently re-entering the closed state from the open state.

[0134] like Figure 2 As shown, when the actuator of the semi-active suspension 50 is controlled to re-enter the closed state, the dynamic stiffness and damping force of the semi-active suspension 50 can be adjusted to be equal to or greater than a specified level in the bounce frequency band which is the main excitation source of road vibration, and thus riding vibration damping by the semi-active suspension 50 can be achieved.

[0135] Thereafter, after the actuator controlling the semi-active mount 50 reenters the closed state from the open state, the suspension controller 40 determines whether a condition for the actuator controlling the semi-active mount 50 to return from the closed state to the open state again is satisfied.

[0136] That is, after the actuator controlling the semi-active suspension 50 re-enters the closed state from the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the rough road weight prvH for a third reference time prvB+prvD (which is longer than the first reference time prvB but shorter than the second reference time prvC) (S209).

[0137] After controlling the actuator of the semi-active suspension 50 to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the rough road weight prvH for a third reference time prvB+prvD (which is longer than the first reference time prvB but shorter than the second reference time prvC), the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state again (S210).

[0138] In this case, the actuator of the semi-active suspension 50 re-enters the closed state from the open state as a situation requiring repeated aftershock control, and therefore, the third reference time prvB+prvD can be set to 3 seconds, which is longer than the first reference time prvB but shorter than the second reference time prvC.

[0139] When the actuator controlling the semi-active suspension 50 returns from the closed state to the open state again, the dynamic stiffness of the semi-active suspension 50 can be adjusted to be less than a specified low level in the full frequency band, such as Figure 1 As shown, improvements in NVH performance, such as reduction in idle vibration and roar noise transmitted to the vehicle interior, can be achieved.

[0140] Hereinafter, a suspension control method for a vehicle according to still another embodiment of the present disclosure performed based on the above-mentioned configuration will be described as follows.

[0141] Figure 7 is a flow chart showing a suspension control method for a vehicle in a case where a road surface condition is determined to be a bumpy road surface condition.

[0142] First, it is determined whether an opening or closing control condition of the semi-active mount 50 is satisfied during vehicle driving ( S301 ).

[0143] For example, when the vehicle is in the starting state, the suspension controller 30 and the suspension controller 40 receive a signal from the engine controller indicating that the engine speed is 1200RPM-1600RPM and receive a signal from the accelerator pedal position sensor indicating that the depression amount of the accelerator pedal is 10%-90%, it can be determined that the conditions for controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state or from the closed state to the open state are met.

[0144] Therefore, when it is determined that the opening or closing control conditions of the semi-active suspension 50 are met, the camera 10 can capture the road surface condition of the road in front of the vehicle, and the wheel acceleration sensor 20 installed on the front wheel of the vehicle can detect the vertical acceleration acting on the front wheel.

[0145] Thereafter, the suspension controller 30 may determine that the road surface condition of the road is a bumpy road surface condition based on the photographing information of the camera 10 and the value detected by the wheel acceleration sensor 20 ( S302 ).

[0146] For example, the suspension controller 30 may identify information about the road surface condition of the road determined based on the shooting information of the camera 10 (i.e., the road surface condition shooting information) as a number, and when the identification value is equal to or greater than a reference value prvE (e.g., 2), the road surface condition of the road may be determined as a bumpy road surface condition. In addition, when there is a bump within a set distance (e.g., 20 m) in front of the vehicle based on the shooting information of the camera 10 or when the vehicle passes over a bump, the suspension controller 30 may determine that the road surface condition of the road is a bumpy road surface condition.

[0147] Thereafter, when the road condition transmitted from the suspension controller 30 is determined to be a bumpy road condition, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 installed on the left front wheel or the right front wheel is equal to or greater than the value obtained by multiplying the reference value prvA by the bump weight prvL (S303).

[0148] As a result of the determination, when the value detected by the wheel acceleration sensor 20 is equal to or greater than the value obtained by multiplying the reference value prvA by the bump weight prvL, the suspension controller 40 controls the actuator of the semi-active suspension 50 from the open state to the closed state, thereby entering aftershock control (driving vibration damping control) (S304).

[0149] Specifically, when the vertical acceleration acting on the front wheel (i.e., the value detected by the wheel acceleration sensor 20) is equal to or greater than the value obtained by multiplying the reference value prvA by the bump weight prvL, the suspension controller 40 determines that the road is bumpy and aftershock control (driving vibration damping control) is required, thereby controlling the actuator of the semi-active suspension 50 from an open state to a closed state.

[0150] Here, the pitch weight prvL may be set to 0.2, which is a value that greatly reduces the reference value prvA, so that the aftershock control (travel vibration damping control) is more easily performed compared with the normal road surface condition and the rough road surface condition.

[0151] like Figure 2 As shown, when the actuator of the semi-active suspension 50 is controlled to enter a closed state according to the bumpy road condition in order to perform aftershock control (driving vibration damping control), the dynamic stiffness and damping force of the semi-active suspension 50 can be adjusted to be equal to or greater than a specified level in the bouncing frequency band which is the main excitation source of road vibration, and thus driving vibration damping can be achieved through the semi-active suspension 50.

[0152] Thereafter, the suspension controller 40 determines whether a condition for controlling the actuator of the semi-active suspension 50 to return to the open state is satisfied ( S305 ).

[0153] That is, after the actuator controlling the semi-active mount 50 enters the closed state from the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the bump weight prvL for the first reference time prvB.

[0154] After controlling the actuator of the semi-active suspension 50 to enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the bump weight prvL for a first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state (S306).

[0155] When the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, the dynamic stiffness of the semi-active suspension 50 can be adjusted to be less than a specified low level in the full frequency band, such as Figure 1 As shown, improvements in NVH performance, such as reduction in idle vibration and roar noise transmitted to the vehicle interior, can be achieved.

[0156] Thereafter, after the actuator controlling the semi-active mount 50 returns from the closed state to the open state, the suspension controller 40 determines whether a condition for the actuator controlling the semi-active mount 50 to re-enter the closed state from the open state is satisfied within the second reference time prvC.

[0157] That is, after the actuator controlling the semi-active suspension 50 returns from the closed state to the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the value obtained by multiplying the reference value prvA by the bump weight prvL again within a second reference time prvC that is longer than the first reference time prvB (S307).

[0158] After controlling the actuator of the semi-active suspension 50 to return from the closed state to the open state, when the value detected by the wheel acceleration sensor 20 becomes equal to or greater than the value obtained by multiplying the reference value prvA by the bump weight prvL again within the second reference time prvC which is longer than the first reference time prvB, the suspension controller 40 controls the actuator of the semi-active suspension 50 to re-enter the closed state from the open state (S308).

[0159] Here, the second reference time prvC may be set to be 6 seconds longer than the first reference time prvB in order to suppress the actuator of the semi-active mount 50 from frequently re-entering the closed state from the open state.

[0160] like Figure 2 As shown, when the actuator of the semi-active suspension 50 is controlled to re-enter the closed state on a bumpy road, the dynamic stiffness and damping force of the semi-active suspension 50 can be adjusted to be equal to or greater than a specified level in the bounce frequency band which is the main excitation source of road surface vibration, and thus riding vibration damping by the semi-active suspension 50 can be achieved.

[0161] Thereafter, after the actuator controlling the semi-active mount 50 reenters the closed state from the open state, the suspension controller 40 determines whether a condition for the actuator controlling the semi-active mount 50 to return from the closed state to the open state again is satisfied.

[0162] That is, after the actuator controlling the semi-active suspension 50 re-enters the closed state from the open state, the suspension controller 40 determines whether the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the bump weight prvL for a third reference time prvB+prvD (S309) that is longer than the reference time prvB but shorter than the second reference time prvC.

[0163] After controlling the actuator of the semi-active suspension 50 to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor 20 becomes smaller than the value obtained by multiplying the reference value prvA by the bump weight prvL for a third reference time prvB+prvD that is longer than the first reference time prvB but shorter than the second reference time prvC, the suspension controller 40 controls the actuator of the semi-active suspension 50 to return from the closed state to the open state again (S310).

[0164] Here, the actuator of the semi-active suspension 50 re-enters the closed state from the open state as considered to be a situation requiring repeated aftershock control, and therefore, the third reference time prvB+prvD may be set to 3 seconds, which is longer than the first reference time prvB but shorter than the second reference time prvC.

[0165] When the actuator controlling the semi-active suspension 50 returns from the closed state to the open state again, the dynamic stiffness of the semi-active suspension 50 can be adjusted to be less than a specified low level in the full frequency band, such as Figure 1 As shown, improvements in NVH performance, such as reduction in idle vibration and roar noise transmitted to the vehicle interior, can be achieved.

[0166] As a test example of the suspension control system according to the present disclosure, when the vehicle passes over a bumpy road with the semi-active suspension turned on during driving, the acceleration of the front wheel steering knuckle, the acceleration of the powertrain, and the acceleration of the vehicle body are measured, and the measurement results are shown in FIG. Figure 8 In the left figure in FIG. 1 , and when the vehicle passes over a bumpy road in the closed state of the semi-active suspension during driving, the acceleration of the front wheel steering knuckle, the acceleration of the powertrain, and the acceleration of the vehicle body are measured, and the measurement results are shown in FIG. Figure 8 In the right picture.

[0167] like Figure 8 As shown, it can be confirmed that when the vehicle in the closed state of the semi-active suspension passes through a bumpy road, the driving vibration of the vehicle including the vertical vibration of the engine is increased by 10%-20% or more compared to when the vehicle in the open state of the semi-active suspension passes through a bumpy road.

[0168] In addition, as another test example of the suspension control system according to the present disclosure, Fig. 9 As shown, it can be confirmed that when the vehicle passes through a Belgian road paved with a large number of cobblestones, the vehicle's driving vibration including the vertical vibration of the body and the vertical vibration of the powertrain is improved by about 1.2 dB in the closed state of the semi-active suspension compared to the open state of the semi-active suspension.

[0169] In addition, as another test example of the suspension control system according to the present disclosure, Fig.10 As shown, it can be confirmed that when the vehicle passes over a concrete road which is a rough road, the driving vibration of the vehicle including the vertical vibration of the vehicle body and the vertical vibration of the powertrain is improved by about 1.2 dB in the closed state of the semi-active suspension compared to the open state of the semi-active suspension.

[0170] As is apparent from the above description, the suspension control system and method for a vehicle according to the present disclosure provide the following effects.

[0171] First, when the suspension controller controls the actuator of the semi-active suspension to remain in an open state based on the road condition information of the road in front of the vehicle determined by the suspension controller and the value detected by the wheel acceleration sensor installed on the corresponding wheel, the dynamic stiffness of the semi-active suspension can be adjusted to be less than a specified low level, and thus improvements in NVH performance, such as reduction in idle vibration and roaring noise, can be achieved.

[0172] Second, when the suspension controller controls the actuator of the semi-active suspension to enter the closed state from the open state based on the road condition information of the road in front of the vehicle determined by the suspension controller and the value detected by the wheel acceleration sensor on the corresponding wheel, the dynamic stiffness and damping force of the semi-active suspension can be adjusted to be equal to or greater than the specified level, and therefore, the driving vibration damping performance of the semi-active suspension depending on the road condition can be improved.

[0173] Third, through the collaborative control between the suspension controller of the electronically controlled suspension system with road prediction and the suspension controller configured to control the opening / closing of the actuator of the semi-active suspension, the improvement of the NVH performance of the semi-active suspension and the improvement of the driving vibration damping performance according to the road conditions can be achieved together.

[0174] The present disclosure has been described in detail with reference to its preferred embodiments. However, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A suspension control system for a vehicle, comprising: A camera configured to capture a road surface condition of a road in front of the vehicle; a plurality of wheel acceleration sensors mounted on the front wheels of the vehicle and configured to detect vertical acceleration acting on the front wheels; a suspension controller configured to determine a road surface condition of the road based on photographing information of the camera and a value detected by the wheel acceleration sensor; as well as A suspension controller is configured to control the semi-active suspension to an on state or a off state based on the road surface condition determination information transmitted from the suspension controller and the values ​​detected by the plurality of wheel acceleration sensors.

2. The suspension control system according to claim 1, wherein: The suspension controller determines the road condition of the road as one of a normal road condition, a rough road condition and a bumpy road condition, and when the road roughness value of the road is less than a reference value, the suspension controller determines the road condition of the road as the normal road condition, and when the road roughness value of the road is equal to or greater than another reference value, the suspension controller determines the road condition of the road as the rough road condition.

3. The suspension control system according to claim 2, wherein: The suspension controller determines the road surface condition of the road as the bumpy road surface condition when there is a bump within a set distance in front of the vehicle or when the vehicle is passing over a bump.

4. The suspension control system according to claim 1, wherein: When the road condition of the road transmitted from the suspension controller is determined to be a normal road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than another reference value, the suspension controller controls the semi-active suspension to enter a closed state from an open state.

5. The suspension control system according to claim 4, wherein: After controlling the semi-active mount to enter the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than a reference value for a first reference time, the suspension controller controls the semi-active mount to return from the closed state to the open state.

6. The suspension control system according to claim 5, wherein: After controlling the semi-active suspension to return to the open state from the closed state, when the value detected by the wheel acceleration sensor becomes equal to or greater than the reference value again within a second reference time longer than the first reference time, the suspension controller controls the semi-active suspension to re-enter the closed state from the open state.

7. The suspension control system according to claim 6, wherein: After controlling the actuator of the semi-active suspension to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the reference value for a third reference time, the suspension controller controls the semi-active suspension to return from the closed state to the open state again, wherein the third reference time is longer than the first reference time, but the third reference time is shorter than the second reference time.

8. The suspension control system according to claim 1, wherein: In a case where a road condition of the road transmitted from the suspension controller is determined to be a rough road condition, when a value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than a value obtained by multiplying another reference value by a rough road weight, the suspension controller controls the semi-active suspension to enter a closed state from an open state.

9. The suspension control system according to claim 8, wherein: After controlling the semi-active suspension to enter the closed state from the open state, when a value detected by the wheel acceleration sensor becomes smaller than a value obtained by multiplying a reference value by a rough road weight for a first reference time, the suspension controller controls the semi-active suspension to return from the closed state to the open state.

10. The suspension control system according to claim 9, wherein: After controlling the semi-active suspension to return to the open state from the closed state, when the value detected by the wheel acceleration sensor becomes equal to or greater than the value obtained by multiplying the reference value by the rough road weight again within a second reference time longer than the first reference time, the suspension controller controls the semi-active suspension to re-enter the closed state from the open state.

11. The suspension control system according to claim 10, wherein: After the actuator controlling the semi-active suspension re-enters the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the value obtained by multiplying the reference value by the rough road weight for a third reference time, the suspension controller controls the semi-active suspension to return from the closed state to the open state again, wherein the third reference time is longer than the first reference time, but the third reference time is shorter than the second reference time.

12. The suspension control system according to claim 1, wherein: In a case where the road condition of the road transmitted from the suspension controller is determined to be a bumpy road condition, when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than a value obtained by multiplying another reference value by the bump weight, the suspension controller controls the semi-active suspension to enter a closed state from an open state.

13. The suspension control system according to claim 12, wherein: After controlling the semi-active suspension to enter the closed state from the open state, when the value detected by the wheel acceleration sensor becomes smaller than the value obtained by multiplying the reference value by the bump weight for a first reference time, the suspension controller controls the semi-active suspension to return from the closed state to the open state.

14. The suspension control system according to claim 13, wherein: After controlling the semi-active suspension to return to the open state from the closed state, when the value detected by the wheel acceleration sensor becomes equal to or greater than the value obtained by multiplying the reference value by the bump weight again within a second reference time longer than the first reference time, the suspension controller controls the semi-active suspension to re-enter the closed state from the open state.

15. The suspension control system according to claim 14, wherein: After controlling the actuator of the semi-active suspension to re-enter the closed state from the open state, when the value detected by the wheel acceleration sensor is less than the value obtained by multiplying the reference value by the bump weight for a third reference time, the suspension controller controls the semi-active suspension to return from the closed state to the open state again, wherein the third reference time is longer than the first reference time, but the third reference time is shorter than the second reference time.

16. A suspension control method for a vehicle, comprising: The road conditions of the road ahead of the vehicle are photographed by a camera; detecting a vertical acceleration acting on the front wheel by a wheel acceleration sensor mounted on the front wheel of the vehicle; determining, by a suspension controller, a road surface condition of the road based on the photographing information of the camera and the value detected by the wheel acceleration sensor; as well as The semi-active suspension is controlled to be in an on state or in an off state by a suspension controller based on the road surface condition determination information transmitted from the suspension controller and the value detected by the wheel acceleration sensor.

17. The suspension control method according to claim 16, wherein: When the suspension controller determines the road condition of the road as one of a normal road condition, a rough road condition and a bumpy road condition, when the road roughness value of the road is less than a reference value, the road condition of the road is determined as the normal road condition, when the road roughness value of the road is equal to or greater than another reference value, the suspension controller determines the road condition of the road as the rough road condition, and when there is a bump within a set distance in front of the vehicle or when the vehicle is passing over a bump, the suspension controller determines the road condition of the road as the bumpy road condition.

18. The suspension control method according to claim 16, wherein: When the road condition of the road transmitted from the suspension controller is determined to be a normal road condition, and when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than another reference value, the suspension controller controls the semi-active suspension to enter a closed state from an open state.

19. The suspension control method according to claim 16, wherein: When the road condition of the road transmitted from the suspension controller is determined to be a normal road condition, and when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than a value obtained by multiplying another reference value by a rough road weight, the semi-active suspension is controlled by the suspension controller to enter a closed state from an open state.

20. The suspension control method according to claim 16, wherein: When the road condition of the road transmitted from the suspension controller is determined to be a normal road condition, and when the value detected by the wheel acceleration sensor installed on one of the front wheels is equal to or greater than a value obtained by multiplying another reference value by the bump weight, the semi-active suspension is controlled by the suspension controller to enter a closed state from an open state.

Images