Active suspension device and suspension control device

Abstract

The present invention provides an active suspension device and a control device for the suspension that can prevent the potential risk of deterioration of the comfort of passengers. An ECU (4) is a control device for a damping force variable shock absorber for damping relative vibration between a vehicle body component (1) and a wheel (16), and comprises: a road surface height measuring unit (41) that measures the height of a road surface at more than three points along the vehicle width direction in front of a tire (15) provided on the wheel (16); a position detecting unit (42) that detects a position where the difference in the height of adjacent road surfaces among the three or more road surface heights measured by the road surface height measuring unit (41) is greater than a specified threshold; and a correction unit (43) that corrects the height of the road surface at a position where the difference detected by the position detecting unit (42) is greater than a specified threshold to a specified height.

Description

Technical Field

[0001] The invention relates to an active suspension device and a suspension control device. Background Art

[0002] Patent document 1 discloses "a control device for an active suspension, which detects a displacement X and a vertical acceleration G of a road surface at the front end of a vehicle body and memorizes them in time sequence; when the displacement detection is normal, the displacement of the road surface when the vehicle passes is estimated by the displacement X, and the actuating mechanisms of the front and rear wheels are controlled according to the estimated displacement of the road surface; when the displacement detection is abnormal, the vertical acceleration of a portion corresponding to the rear wheel of the vehicle body is estimated based on the wheelbase Lw and the vehicle speed by the vertical acceleration G, and the actuating mechanism of the rear wheel is controlled according to the estimated vertical acceleration" (for example, refer to the abstract of patent document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 5-96922 Summary of the invention

[0006] In the control device of the active suspension disclosed in Patent Document 1, the control mechanism determines whether the displacement detection performed by the road surface detection mechanism is normal. When it is determined that the displacement detection is normal, the displacement of the road surface when the vehicle travels the predicted distance based on the predicted distance and the vehicle speed is at least estimated by the displacement of the road surface memorized in the memory mechanism, and the actuator mechanism is controlled according to the estimated displacement of the road surface.

[0007] On the other hand, when it is determined that the displacement detection is abnormal, the control mechanism estimates the up and down acceleration of the part of the vehicle body corresponding to the rear wheels when the vehicle has traveled the wheelbase distance based on the wheelbase and the vehicle speed through the up and down acceleration memorized in the memory mechanism, and controls the actuator mechanism of the rear wheels according to the estimated up and down acceleration.

[0008] In this way, when it is determined that the displacement detection is abnormal, the actuating mechanism of the rear wheel is controlled based on the vertical acceleration estimated from the vertical acceleration stored in the memory mechanism, which may deteriorate the comfort of the occupants.

[0009] The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide an active suspension device and a suspension control device that can prevent the potential risk of deterioration of the comfort of passengers.

[0010] The active suspension device of the present invention is a control device for a variable damping force shock absorber for attenuating relative vibration between a vehicle body and a wheel, and is characterized in that it comprises: a road surface height measuring mechanism, which measures the height of the road surface at more than three points along the vehicle width direction in front of a tire arranged on the wheel; a position detecting mechanism, which detects a position where the difference in the height of adjacent road surfaces among the three or more road surfaces measured by the road surface height measuring mechanism is greater than a prescribed threshold value; and a correction mechanism, which corrects the height of the road surface at a position where the difference detected by the position detection mechanism and where the difference is greater than the prescribed threshold value to a prescribed height.

[0011] Effects of the Invention

[0012] According to the present invention, an active suspension device and a suspension control device are provided that can prevent a potential risk of deterioration of the comfort of a vehicle occupant. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram showing the configuration of a vehicle to which a suspension control device according to an embodiment of the present invention is applied.

[0014] Figure 2 It is a side view of a vehicle showing a sensor mounting structure in this embodiment.

[0015] Figure 3 This is a functional block diagram showing the functions of the ECU according to the present embodiment.

[0016] Figure 4A It is an explanatory diagram showing the measurement result of the height of the road surface measured by the position detection unit along the vehicle width direction in front of the tire.

[0017] Figure 4B This is an explanatory diagram showing the concept of correction of the tire deformable limit value by the correction unit.

[0018] Figure 5A It is an explanatory diagram showing the measurement results of the road surface height at a certain time.

[0019] Figure 5B This is an explanatory diagram (No. 1) showing the measurement results of the road surface height at other times.

[0020] Figure 5C This is an explanatory diagram (part 2) showing the measurement results of the road surface height at other times.

[0021] Figure 5D This is an explanatory diagram (part 3) showing the measurement results of the road surface height at other times.

[0022] Fig. 6AThis is an explanatory diagram showing that the difference in the height of the road surface at one point compared to the road surface height at the measurement point and the height of the adjacent road surface is larger than the first threshold value.

[0023] Figure 6B This is an explanatory diagram showing that the difference in the height of the adjacent road surface between the values ​​of the height of the road surface at two points and the height of the road surface at the measurement point is equal to or greater than a predetermined threshold value.

[0024] Description of Reference Numerals

[0025] 3 Sensors

[0026] 4 ECU (active suspension device)

[0027] 41 Road surface height measurement department

[0028] 42 Position detection unit

[0029] 43 Correction Department

[0030] 44 Road surface condition judgment unit DETAILED DESCRIPTION

[0031] The following describes in detail the mode for implementing the present invention. In addition, the embodiment described below is an example for realizing the present invention, and should be able to be appropriately modified or changed according to the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the following embodiment. In addition, it is also possible to appropriately combine parts of each embodiment described later to form a structure.

[0032] Figure 1 A schematic configuration diagram of a vehicle V to which a suspension control device according to an embodiment of the present invention is applied is shown. Figure 2 3 is a side view of a vehicle V showing the installation structure of the sensor 3 in this embodiment. Figure 2 , the outer shape of the vehicle V is indicated by a two-dot chain line.

[0033] like Figure 1 or Figure 2 As shown, the structure of the vehicle (automobile) V includes a body part 1, an exterior part 2, a sensor 3, and an ECU (Electronic Control Unit) 4. The form and type of the vehicle V are not particularly limited as long as it is an automobile including the body part 1, the exterior part 2, the sensor 3, and the ECU 4. That is, the vehicle V is a passenger car, a bus, a truck, a work vehicle, etc.

[0034] The vehicle body part 1 of the vehicle V is provided with a wheel 16 equipped with a tire 15 on the front wheel. Each of the front wheels 16 is suspended on the exterior part 2 via a suspension composed of a suspension arm 18, a spring 20, a damping force variable shock absorber (hereinafter referred to as a shock absorber D), etc. In addition, in this embodiment, an electromagnetic shock absorber is described as an example, but it is not limited to this, and it can also be applied to an air suspension and an active suspension using an active stabilizer. In addition, in this embodiment, the front wheel is described as an example, but the rear wheel can also adopt the same structure as the front wheel 16.

[0035] like Figure 2 As shown, the vehicle body member 1 supports the exterior member 2 and is composed of a front side frame 11, an upper member 12, a bumper beam extension 13, and a bumper beam 14 (frame member).

[0036] The exterior component 2 is a component that forms the outer side (outer contour) of the vehicle V. The exterior component 2 is composed of a hood 21, a front bumper 22 (bumper), and a front fender 23. The hood 21 is a panel component that covers the upper surface in front of the front glass. The front bumper 22 is located on the front surface side of the vehicle V, and is composed of, for example, a panel component made of synthetic resin. In addition, the front bumper 22 has a front surface portion 22a where an air intake port and the like are provided, and a bottom portion 22b that extends from the lower end of the front surface portion 22a toward the rear. The front fender 23 is a panel component that covers the periphery of the wheel 16.

[0037] like Figure 1 as well as Figure 2 As shown in FIG. 1 , the sensor 3 is a shock absorber control sensor for detecting the state of the road surface R in front of the vehicle V (road surface state) and controlling the shock absorber D of the vehicle V. The sensor 3 obtains information related to the height of the road surface at three or more points. The sensor 3 is fixed to the upper member 12 (see FIG. 1 ) located in front of the wheel 16. Figure 2 ).like Figure 2 As shown by the solid arrow, the sensor 3 in this embodiment is configured to detect the state of the road surface R directly in front of the wheel 16, and can be appropriately selected from radar type, camera type, laser type, etc. sensors. In addition, the sensor 3 is not limited to a single sensor, and can also be composed of a combination of multiple types of sensors such as camera type and laser type.

[0038] Figure 1 The ECU 4 (active suspension device) shown is a device that controls the shock absorber D for damping the relative vibration between the vehicle body member 1 and the wheel 16. In the present embodiment, the sensor 3 and the ECU 4 constitute a road surface state detection means.

[0039] The ECU 4 is composed of a microcomputer, ROM, RAM, peripheral circuits, input / output interfaces, various drivers, etc. The ECU 4 is electrically connected to each sensor 3 and the shock absorber D of each wheel 16 via a communication circuit (e.g., CAN (Controller Area Network): not shown). In addition, the ECU 4 and the sensor 3 constitute a suspension control device (suspension control device). In other words, the suspension control device is configured such that the sensor 3 and the ECU 4 constitute a road surface state detection mechanism, and control the suspension including the shock absorber D.

[0040] In the present embodiment, the shock absorber D is constituted by, for example, a single-tube (de Carbon (name) type) shock absorber. The shock absorber D is housed relative to a cylindrical hydraulic cylinder filled with a magneto-rheological fluid (MRF) in such a manner that the piston rod can slide along the axial direction, and the piston installed on the top end of the piston rod divides the hydraulic cylinder into an upper oil chamber and a lower oil chamber. Between the upper oil chamber and the lower oil chamber, there is a connecting passage that connects the upper oil chamber and the lower oil chamber. An MLV coil is arranged on the inner side of the connecting passage. In the shock absorber D, for example, the lower end of the hydraulic cylinder is connected to the suspension arm 18 as a wheel side component, and the upper end of the piston rod is connected to the shock absorber base as a vehicle body side component.

[0041] In addition, if current is supplied from the ECU 4 to the MLV coil (not shown) of the shock absorber D, a magnetic field is applied to the MRF flowing in the connecting passage, and the ferromagnetic particles form lock-shaped clusters. As a result, the viscosity of the MRF passing through the connecting passage increases significantly, and the damping force of the shock absorber D increases. In addition, in this embodiment, a single-tube shock absorber is used for the shock absorber D, but other types of shock absorbers can also be appropriately used.

[0042] Figure 3 ECU 4 is a functional block diagram showing the functions of ECU 4 of the present embodiment. ECU 4 functions as a road surface height measuring unit 41 , a position detecting unit 42 , a correcting unit 43 , and a road surface state determining unit 44 by executing a program stored in a ROM (not shown).

[0043] The road surface height measuring unit 41 measures the height of the road surface at three or more points along the vehicle width direction in front of the tire 15 provided on the wheel 16. For example, the sensor 3 obtains information related to the height of the road surface at three or more points. The sensor 3 obtains the reflected light of the laser from the road surface R and detects the state of the road surface R in front of the vehicle V (road surface state). Thus, the road surface height measuring unit 41 obtains the road surface state from the sensor 3 and measures the height of the road surface at three or more points along the vehicle width direction in front of the tire 15 provided on the wheel 16.

[0044] The position detection unit 42 detects a position where a difference in height between adjacent road surfaces among the heights of the road surface at three or more points measured by the road surface height measurement unit 41 is equal to or larger than a predetermined threshold value.

[0045] Figure 4A 1 is an explanatory diagram showing a measurement result of the height of the road surface measured by the position detection unit 42 along the vehicle width direction in front of the tire 15 .

[0046] like Figure 4A As shown in FIG. 1 , the horizontal axis represents the width direction of the tire 15, and the vertical axis represents the height of the road surface in front of the tire 15. Figure 4A , road surface heights HT1 to HT5 at measurement points MP1 to MP5 in front of the tire 15 are indicated.

[0047] The correction unit 43 corrects the height of the road surface at the position where the difference detected by the position detection unit 42 is greater than the predetermined threshold value TL to a predetermined height. For example, the correction unit 43 corrects the heights HT3 and HT4 of the road surface at the position where the difference detected by the position detection unit 42 is greater than the predetermined threshold value TL to predetermined heights CP1 and CP2.

[0048] Specifically, the correction unit 43 corrects the heights HT3 and HT4 of the road surface whose difference is greater than the predetermined threshold value TL to the previously known limit values ​​(hereinafter referred to as deformation boundaries) at which the tire 15 can be deformed, based on the height HT2 of the road surface at the measuring point MP2. In addition, the correction unit 43 corrects the limit values ​​at which the tire 15 can be deformed by an example of the present embodiment and is not limited thereto.

[0049] Figure 4B 1 is an explanatory diagram (tire deformation pattern) showing the concept that the correction unit 43 corrects the height of the road surface to a limit value at which the tire 15 can be deformed. Figure 4B The tire deformation pattern shown indicates that, when the measured height of the road surface exceeds the deformation boundary of the tire 15 on the road surface R, the correction unit 43 corrects the measured height of the road surface to the deformation boundary of the tire 15 .

[0050] For example, Figure 4A In the case where the road surface height HT2 at the measuring point MP2 and the road surface heights HT3 and HT4 at the measuring points MP3 and MP4 exceed the prescribed threshold value TL, the correction unit 43 corrects the road surface height HT3 at the measuring point MP3 to a prescribed height CP1 (deformation boundary of the tire deformation mode) indicating the limit value at which the tire 15 can be deformed, and corrects the road surface height HT4 at the measuring point MP4 to a prescribed height CP2 (deformation boundary of the tire deformation mode) indicating the limit value at which the tire 15 can be deformed.

[0051] On the other hand, the road surface state determination unit 44 (see Figure 3) excludes the height of the road surface at the position detected by the position detection unit 42, where the difference is greater than the predetermined threshold value TL, and determines the state of the road surface based on the height of the road surface where the difference in the height of the adjacent road surface is less than the predetermined threshold value. In addition, the correction unit 43 and the road surface state determination unit 44 can be used in combination with each other as arbitrary components.

[0052] When the ECU 4 has a road surface state determination unit 44, the correction unit 43 corrects the road surface height at a position where the difference in the height of the adjacent road surfaces is less than the predetermined threshold TL to a value that is greater than the predetermined threshold TL. FIG. 5A to FIG. 5D An example of correction performed by the correction unit 43 will be described.

[0053] Figure 5A It is an explanatory diagram showing the measurement results of the road surface height at a certain time (heights HT1 to HT5 from the road surface). Figure 5A In the middle, it means that, for example, among the measurement points MP1 to MP5, there is no measurement point whose height difference with the adjacent road surface is equal to or greater than a predetermined threshold.

[0054] In this case, in this embodiment, the ECU 4 Figure 5A The road surface heights HT1 to HT5 at the respective measurement points MP1 to MP5 are used as values ​​for controlling the shock absorber D.

[0055] Figure 5B 2 is an explanatory diagram showing the measurement results of the road surface height (heights HU1 to HU5 from the road surface) at other times. Figure 5B As shown, for example, among the measuring points MP1 to MP5, the difference between the height HU2 from the road surface at the measuring point MP2 and the height HU1 of the adjacent road surface (or the height HU3 of the road surface) is greater than the first threshold TL1 (predetermined threshold). In this case, the road surface state determination unit 44 excludes the value of the height HU2 from the road surface at the measuring point MP2, and determines the state of the road surface based on the heights HU1, HU3, HU4, and HU5 of the adjacent road surfaces whose differences in height are less than the first threshold TL1.

[0056] Therefore, the correction unit 43 corrects the value of the road surface height HU2 at the measuring point MP2 whose difference in height of the adjacent road surfaces is less than the first threshold value TL1 based on the road surface heights HU1, HU3, HU4, and HU5 whose difference in height of the adjacent road surfaces is less than the first threshold value TL1. In other words, the correction unit 43 corrects the value of the road surface height HU2 at the measuring point MP2 so that the difference between the road surface height HU2 and the road surface height HU1 (the height of the adjacent road surface) is less than the first threshold value TL1.

[0057] Therefore, in this embodiment, the ECU 4 Figure 5BAs the control value of the shock absorber D, the corrected value of the road surface heights HU1, HU3, HU4, HU5 in FIG. 1 and the road surface height HU2 at the measuring point MP2 is used.

[0058] Figure 5C : is an explanatory diagram showing the measurement results of the road surface height measured at other times (heights HV1 to HV5 from the road surface). Figure 5C As shown, for example, among the measuring points MP1 to MP5, the difference between the height HV3 from the road surface at the measuring point MP3 and the height HV2 of the adjacent road surface (or the height HV4 of the road surface) is greater than the first threshold value TL1. In this case, the road surface state determination unit 44 excludes the value of the height HV3 from the road surface at the measuring point MP3, and determines the state of the road surface based on the heights HV1, HV2, HV4, and HV5 of the road surfaces for which the difference in the heights of the adjacent road surfaces is less than the first threshold value TL1.

[0059] Therefore, the correction unit 43 corrects the value of the road surface height HV3 at the measurement point MP3 whose difference is greater than the first threshold TL1 after the exclusion based on the road surface heights HV1, HV2, HV4, and HV5 whose difference in height of the adjacent road surfaces is less than the first threshold TL1. In other words, the correction unit 43 corrects the value of the road surface height HV3 at the measurement point MP3 so that the difference between the road surface height HV3 and the road surface height HV2 (the height of the adjacent road surface) is less than the first threshold TL1.

[0060] Therefore, in this embodiment, the ECU 4 Figure 5C As the control value of the shock absorber D, the corrected value of the road surface heights HV1, HV2, HV4, HV5 in FIG. 1 and the road surface height HV3 at the measuring point MP3 is used.

[0061] Figure 5D : is an explanatory diagram showing the measurement results of the road surface height at other times (heights HW1 to HW5 from the road surface). Figure 5D As shown, for example, among the measurement points MP1 to MP5, the difference between the height HW1 from the road surface at the measurement point MP1 and the height HW2 of the adjacent road surface is greater than the first threshold value TL1. In this case, the road surface state determination unit 44 excludes the value of the height HW1 from the road surface at the measurement point MP1, and determines the state of the road surface based on the heights HW2, HW3, HW4, and HW5 of the road surfaces for which the difference in the heights of the adjacent road surfaces is less than the first threshold value TL1.

[0062] Therefore, the correction unit 43 corrects the value of the road surface height HW1 at the measuring point MP1, which has a difference of more than the first threshold value TL1, based on the road surface heights HW2, HW3, HW4, and HW5 whose differences in the heights of the adjacent road surfaces are less than the first threshold value TL1. In other words, the correction unit 43 corrects the value of the road surface height HW1 at the measuring point MP1 so that the difference between the road surface height HW2 (the height of the adjacent road surface) and the road surface height HW2 is less than the first threshold value TL1.

[0063] Therefore, in this embodiment, the ECU 4 Figure 5D The road surface heights HW2, HW3, HW4, and HW5 in FIG. 1 and the corrected value of the road surface height HW1 at the measurement point MP1 are used as the values ​​for the shock absorber D control.

[0064] In this way, when the height of a road surface at one point exceeds the first threshold value TL1 from the height of an adjacent road surface, the ECU 4 can exclude the value of the height of the road surface at the point that exceeds the first threshold value TL1, and judge the state of the road surface based on the height of other road surfaces whose difference is less than the first threshold value TL1. In this case, as long as the heights of the road surfaces are adjacent, the measurement point can be on the right side or on the left side of the tire 15 without limitation.

[0065] Furthermore, the position detection unit 42 may set a second threshold value for detecting the difference in height of the road surface at two points larger than the first threshold value for detecting the difference in height of the road surface at one point, when there is one point or two points where the difference in height of the adjacent road surfaces is equal to or greater than a predetermined threshold value. Here, the relationship between the first threshold value and the second threshold value is described in detail by comparison using the accompanying drawings.

[0066] Fig. 6A The value of the height HU2 of the road surface at one point indicates that the difference between the heights HU1 and HU3 of the road surfaces at the measurement points MP1 and MP3 is greater than the first threshold value TL1. Figure 6B The values ​​of the heights HT6 and HT7 of the road surface at the two points indicate that the difference in the heights of the adjacent road surfaces is greater than a predetermined threshold value compared to the heights 0 and HT3 of the road surface at the measurement points 0 and MP1. Fig. 6A as well as Figure 6B and Figure 5A as well as Figure 5B The same reference numerals are used to denote common parts, and description thereof will be omitted as appropriate. In addition, the first threshold TL1 and the second threshold TL2 are variable.

[0067] exist Fig. 6A In the figure, the difference in the height of the adjacent road surface between the road surface height HU2 and the road surface height HU1 and the road surface height HU3 is greater than the first threshold TL1, and is therefore excluded as a point that deviates from the road surface height for determining the road surface state.

[0068] On the other hand, Figure 6B In the example, the position detection unit 42 detects the two positions of the road surface heights HT6 and HT7 as positions where the difference in the heights of adjacent road surfaces is greater than a predetermined threshold. Figure 6B As shown, the position detection unit 42 sets the second threshold TL2 for detecting the difference in height between two road surfaces to be larger than the first threshold TL1 for detecting the difference in height between one road surface. Thus, the position detection unit 42 can make it difficult to exclude the heights HT6 and HT7 of the two road surfaces as separation points, compared with the case where the heights HT6 and HT7 of the one road surface are respectively detected.

[0069] Here, for example, assuming that the first threshold value TL1 and the second threshold value TL2 are the same value, the road surface state determination unit 44 will set Figure 6B The heights HT6 and HT7 of the two adjacent road surfaces shown are detected as exclusion points, which is not appropriate when considering the actual road surface height.

[0070] Therefore, the position detection unit 42 increases the second threshold TL2 for detecting the difference in height between two road surfaces compared to the first threshold TL1 for detecting the difference in height between one road surface point, thereby making it difficult for the values ​​of the heights HT6 and HT7 of two adjacent road surfaces to be detected as exclusion points.

[0071] Thus, the road surface state judgment unit 44 can avoid excluding the heights HT6 and HT7 of the two adjacent road surfaces as exclusion points, so the ECU 4 can improve the accuracy of judging the state of the road surface. In addition, the relationship between the second threshold TL2 and the first threshold TL1 only needs to be greater than the first threshold TL1, and does not need to be determined by an absolute value.

[0072] <First embodiment>

[0073] The ECU 4 of the first embodiment is composed of: a road surface height measuring unit 41, which measures the height of the road surface at more than three points along the vehicle width direction in front of the tire 15 provided on the wheel 16; a position detection unit 42, which detects the position where the difference in the height of adjacent road surfaces among the heights of the road surface at more than three points measured by the road surface height measuring unit 41 is greater than a prescribed threshold; a road surface state judgment unit 44, which excludes the value of the height of the road surface at the position where the difference is greater than the prescribed threshold detected by the position detection unit 42, and judges the state of the road surface based on the height of the road surface where the difference in the height of adjacent road surfaces is less than the prescribed threshold; and a correction unit 43, which corrects the height of the road surface at the position where the difference is greater than the prescribed threshold detected by the position detection unit 42 to a prescribed height.

[0074] Thus, the ECU 4 of the first embodiment measures the height of the road surface at three or more points along the vehicle width direction in front of the tire 15 provided on the wheel 16, and corrects the height of the road surface at a position where the difference in the height of the adjacent road surfaces among the measured heights of the road surface at three or more points is greater than a predetermined threshold value to a predetermined height. Therefore, the ECU 4 can appropriately correct the height of the road surface, and thus can improve the detection accuracy of the state of the road surface.

[0075] As described above, the ECU 4 of the first embodiment measures the heights of the road surface at three or more points, and corrects the height of the road surface at a position where the difference between the heights of adjacent road surfaces among the three or more measured heights is equal to or greater than a predetermined threshold to a predetermined height.

[0076] Thus, the ECU 4 of the first embodiment can properly correct the height of the road surface, thereby improving the detection accuracy of the road surface state and preventing the potential deterioration of the comfort of the passengers. Specifically, even if the road surface is paved with metal mesh and stones, the ECU 4 can properly correct the height of the road surface.

[0077] In addition, in the first embodiment, the ECU 4 may also have a road surface condition judgment unit 44, which excludes the value of the height of the road surface at a position where the difference detected by the position detection unit 42 is greater than a specified threshold, and judges the condition of the road surface based on the height of the road surface where the difference in the height of adjacent road surfaces is less than the specified threshold.

[0078] Therefore, the ECU4 of the first embodiment detects the position where the difference in height of adjacent road surfaces is above the specified threshold, excludes the value of the height of the road surface at the position where the detected difference is above the specified threshold, and can judge the state of the road surface based on the height of the road surface where the difference in height of adjacent road surfaces is less than the specified threshold.

[0079] In this case, the correction unit 43 corrects the value of the road surface height excluding the position where the difference is greater than or equal to a predetermined threshold value (eg, first threshold value) based on the road surface height where the difference is less than a predetermined threshold value (eg, first threshold value).

[0080] Moreover, the position detection unit 42 may set a second threshold for detecting the difference in height of two adjacent road surfaces to be larger than a first threshold for detecting the difference in height of the road surface at one point or at two points, when the difference in height of the adjacent road surfaces is greater than a prescribed threshold.

[0081] As described above, the position detection unit 42 increases the second threshold TL2 for detecting the difference in height between two road surfaces compared to the first threshold TL1 for detecting the difference in height between one road surface point, thereby making it difficult for the values ​​of the heights HT6 and HT7 of two adjacent road surfaces to be detected as exclusion points.

[0082] Thus, the road surface state determination unit 44 is less likely to exclude two exclusion points than in the case of excluding one point, and can appropriately determine the state of the road surface.

[0083] Furthermore, the correction unit 43 can correct the height of the road surface at a position where the difference in height between adjacent road surfaces is greater than a predetermined threshold value to the deformation boundary (deformable limit value of the tire deformation mode) of the tire 15. In this case, the deformation boundary of the tire 15 can be applied with the slope of the height of the adjacent road surface.

[0084] Thus, for example, even if the road surface height at the measurement point is correct, if the road surface height exceeds the deformation limit of the tire 15 due to metal mesh, stones, etc., the measurement error can be reduced and the detection accuracy of the road surface state can be improved.

[0085] Here, the deformation boundary of the tire 15 can be changed according to the type of the tire 15. For example, the air pressure of a summer tire used in the summer is usually higher, and the air pressure of a winter tire used in the winter is relatively lower than that of a summer tire. Therefore, the slope of the deformation boundary can be set lower than that of a summer tire used in the summer. In addition, the deformation boundary of the tire 15 can be set by the aspect ratio of the tire 15.

[0086] Alternatively, the deformation boundary of the tire 15 may be applied to the slope of the height of the adjacent road surface, thereby calculating the slope of the road surface height by, for example, distributing the weight of the vehicle V, and variably setting the deformation boundary of the tire 15 .

[0087] For example, by distributing the weight of the vehicle V, the slope of the deformation boundary of the tire 15 on the driver's seat side can be set larger than the deformation boundary of the tire 15 on the passenger seat side, and the deformation boundary can be variably set by distributing the weight of the vehicle V. Thus, the ECU 4 can judge the state of the road surface with high accuracy. By the way, by using the displacement (settlement) of the suspension (shock absorber D) in a flat place and the road surface measurement results, the load applied to each wheel (tire 15) can be grasped, and based on the load, the deformation boundary of the tire 15 can also be set separately.

[0088] In addition, for example, the higher the air pressure is, the smaller the change amount of the tire 15 is, thereby making it possible to set the slope of the deformation boundary of the tire 15 low. In addition, as long as the vehicle is equipped with a tire pressure monitoring system (TPMS), the air pressure of the tire 15 can be always obtained.

[0089] Furthermore, when braking the vehicle V, the correction unit 43 may set a higher slope of the deformation boundary of the tire 15 for the front wheel 16 than for the rear wheel. When the sensor 3 is provided only on the front wheel, it can be applied directly.

[0090] In addition, when turning, a difference may be provided between the wheel on the inner wheel side and the wheel on the outer wheel side for the wheel 16, and the slope value of the deformation boundary of the tire 15 on the outer wheel side may be set high. In addition, when driving normally, it can be directly applied, and when turning on a curve, the slope value can be set high in the direction in which the centrifugal force acts.

[0091] <Second embodiment>

[0092] The ECU 4 of the first embodiment is composed of: a road surface height measuring unit 41, which measures the height of the road surface at more than three points along the vehicle width direction in front of the tire 15 provided on the wheel 16; a position detection unit 42, which detects positions where the difference in height of adjacent road surfaces among the heights of the road surface at more than three points measured by the road surface height measuring unit 41 is greater than a prescribed threshold; and a road surface state judgment unit 44, which excludes the values ​​of the height of the road surface at positions where the difference detected by the position detection unit 42 is greater than the prescribed threshold, and judges the state of the road surface based on the height of the road surface where the difference in height of adjacent road surfaces is less than the prescribed threshold.

[0093] Therefore, the ECU4 of the second embodiment can detect positions where the difference in height of adjacent road surfaces is above a specified threshold, exclude the values ​​of the road surface heights at positions where the detected difference is above the specified threshold, and judge the state of the road surface based on the height of the road surface where the difference in height of adjacent road surfaces is less than the specified threshold.

[0094] As described above, the ECU 4 of the second embodiment excludes the road surface height values ​​detected by the position detection unit 42 at positions where the difference is greater than the predetermined threshold, and determines the state of the road surface based on the road surface heights at which the difference in the heights of adjacent road surfaces is less than the predetermined threshold.

[0095] Therefore, the ECU 4 of the second embodiment can exclude road surface height values ​​whose difference in road surface height is above a specified threshold, and judge the state of the road surface based on the road surface height whose difference in adjacent road surface height is less than the specified threshold, thereby improving the detection accuracy of the road surface state.

[0096] In addition, even if the road surface height at the measurement point with leaves and dust is correct, the ECU 4 can determine the road surface height to be deleted as the state of the road surface as a whole, and can reduce the measurement error of the road surface state. Since the ECU 4 can reduce the measurement error of the road surface state, the accuracy of the detection of the road surface state can be improved. As a result, the ECU 4 can improve the detection accuracy of the road surface state, thereby preventing the worry of deterioration of the comfort of the passengers.

[0097] In particular, the position detection unit 42 may set a second threshold for detecting the difference in height between two points of the road surface to be larger than a first threshold for detecting the difference in height between the two points of the road surface, when there is one point or two points where the difference in height between adjacent road surfaces is greater than a prescribed threshold.

[0098] As described above, the position detection unit 42 makes it difficult for the height values ​​of two adjacent road surfaces to be detected as exclusion points by making the second threshold TL2 for detecting the difference between two road surface heights higher than the first threshold TL1 for detecting the difference between one road surface height.

[0099] Thus, the road surface state determination unit 44 is less likely to exclude two exclusion points than in the case of excluding one point, and can appropriately determine the state of the road surface.

[0100] In addition, the road surface state determination unit 44 may also be provided with a noise removal function. For example, it may be possible to use past information and apply a low-pass filter that cuts off high-frequency components to remove a predetermined exclusion point. It may also be possible to use past information over time (time series) to remove the exclusion point based on the continuity of the measurement point. It may also be possible for the road surface state determination unit 44 to be provided with a noise removal function including time axis information based on the speed information of the vehicle V.

Claims

1. An active suspension device is a control device for a damping force variable shock absorber for damping relative vibration between a vehicle body and a wheel, characterized in that: have: a road surface height measuring mechanism for measuring the height of the road surface at three or more points in the vehicle width direction in front of the tire provided on the wheel; a position detection mechanism for detecting a position at which a difference in height between adjacent ones of the road surfaces at the three or more points measured by the road surface height measurement mechanism is equal to or greater than a predetermined threshold; and A correction means corrects the height of the road surface at the position detected by the position detection means and at which the difference is equal to or greater than the predetermined threshold value, to a predetermined height.

2. The active suspension device according to claim 1, characterized in that: The device further comprises a road surface state judgment unit, which excludes the value of the height of the road surface at the position where the difference detected by the position detection means is greater than the predetermined threshold value, and judges the state of the road surface based on the height of the road surface where the difference in the height of the adjacent road surface is less than the predetermined threshold value, The correction means corrects the value of the road surface height at the excluded position where the difference between the heights of the adjacent road surfaces is equal to or greater than the predetermined threshold value, based on the height of the road surface where the difference between the heights of the adjacent road surfaces is less than the predetermined threshold value.

3. The active suspension device according to claim 2, characterized in that: When there is one point or two points where the difference in height of the adjacent road surfaces is above a prescribed threshold, the position detection mechanism makes a second threshold for detecting the difference in height of the road surface at the two points larger than a first threshold for detecting the difference in height of the road surface at the one point.

4. The active suspension device according to claim 3, characterized in that: The first threshold and the second threshold are variable.

5. The active suspension device according to claim 1, characterized in that: The correction mechanism corrects the height of the road surface at a position equal to or higher than the predetermined threshold value to a limit value at which the tire can be deformed.

6. A suspension control device, characterized in that: have: The active suspension device according to any one of claims 1 to 5; and A sensor is provided for acquiring information on the height of the road surface at the three or more points.

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