JP2009234470A - Suspension control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension control device capable of enhancing forward and rearward visibility of a vehicle when the travel of the vehicle is shifted from a flat traveling road surface to uphill or downhill. <P>SOLUTION: The suspension control device for a vehicle includes: four wheels, which consists of two front wheels 11L, 11R and two rear wheels 12L, 12R supporting a vehicle body; four suspension devices 13, which are provided on each of the four wheels and capable of changing the height of the vehicle body independently corresponding to the positions of the two front wheels and the two rear ones; and a control means 51, which actuates the suspension devices so as to change the vehicle height corresponding to each of the four suspension devices. Furthermore, the suspension control device includes: an information extraction section 52 of inclination state change, which extracts information concerning the change of an inclination state of a road surface to be traveled in the forward direction, and a vehicle height changing means 51A, which actuates the two front wheels or two rear ones and changes the vehicle height of the front part or rear part of the vehicle, from the information concerning the inclined state given from the information-of-inclination-state-change extraction means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle suspension control device, and more particularly, to a vehicle suspension control device that improves the visibility of the front and rear of a vehicle when driving up and down a hill during driving of an automobile.

  When driving a car or the like and traveling on a road, for example, when shifting from a flat traveling road surface to an uphill (uphill road) road surface, due to the posture of the vehicle body, the situation on the way uphill or above for the driver is It is difficult to confirm. In addition, while traveling uphill, a forward-upward pitch behavior occurs with respect to the vehicle body posture, along with the weight balance on the spring of the suspension device and acceleration factors in automobiles, and road conditions such as forward and backward on the uphill road surface and uphill It is difficult to confirm the position of the hill apex. The forward pitch behavior becomes prominent depending on the weight state of the vehicle body and the uneven loading on the trunk.

  The above-mentioned problems related to visibility on the uphill road surface of automobiles can occur in the same way even when moving from a flat road surface to a downhill road surface or while traveling on a downhill road surface. .

As a prior art related to the present invention, there is a vehicle travel control device described in Patent Document 1. In this vehicle travel control device, when the vehicle travels on a travel road inclined in the lateral direction, travel control is performed that suppresses the driver's lateral movement by reducing the tilt state of the vehicle body. In this travel control device, the lateral inclination of the vehicle body is controlled in accordance with the road surface lateral inclination of the road.
JP 2008-001236 A

  The control by the vehicle travel control device described in Patent Document 1 is a control for suppressing the lateral inclination state of the vehicle body with respect to the lateral inclination of the traveling road surface. Conventionally, the vehicle height state and the inclination posture of the vehicle are not controlled in consideration of the inclination state in front of the vehicle traveling road surface.

  When driving a car and driving on a road, for example, when moving from a flat road surface to an uphill road surface, or when moving from a flat road surface to a downhill road surface, the front of the vehicle is visually recognized. A suspension control device that improves the performance is desired.

  In view of the above problems, an object of the present invention is to provide a vehicle suspension control device that can improve the visibility of the front or rear of a vehicle when the vehicle travels from a flat traveling road surface to an uphill or downhill. There is to do.

  In order to achieve the above object, a vehicle suspension control apparatus according to the present invention is configured as follows.

  The vehicle suspension control apparatus according to the present invention is provided on each of the four wheels including the front two wheels and the rear two wheels that support the vehicle body, and the vehicle wheel height corresponding to the positions of the front two wheels and the rear two wheels. Four suspension devices that can be independently changed, and control means for operating the suspension devices so as to arbitrarily change the vehicle height corresponding to each of the four suspension devices. Inclination state change information extracting means for extracting information relating to changes in the inclination state of the vehicle, and the front two wheels or the rear so that the field of view on the inclined road surface is expanded based on the information relating to the change in inclination state given from the inclination state change information extracting means. Vehicle height changing means for operating the two-wheel suspension device and changing the vehicle height at the front or rear of the vehicle body.

  In the above-described vehicle suspension control device, preferably, the vehicle height changing means determines that the information related to the change in the inclination state given from the inclination state change information extraction means determines that the planned road surface is uphill. The vehicle height is changed so as to increase the vehicle height of the two wheels or to decrease the vehicle height of the rear two wheels.

  In the above vehicle suspension control device, preferably, the vehicle height changing means determines that the information related to the change in the inclination state given from the inclination state change information extraction means is the time when the planned road surface is a downhill. The vehicle height is changed so as to lower the vehicle height of the two wheels or raise the vehicle height of the rear two wheels.

  In the above vehicle suspension control device, preferably, the tilt state change information extracting means is configured based on a navigation device mounted on the vehicle.

  In the vehicle suspension control apparatus described above, the inclination state change information extracting means is preferably configured using an acceleration sensor mounted on the vehicle.

  According to the vehicle suspension control apparatus of the present invention, information related to a change in the inclination state (uphill or downhill) of the planned road surface in the traveling direction of the vehicle is extracted, and the field of view regarding the inclined road surface is expanded based on this information. As described above, the front two-wheel or rear two-wheel suspension device is operated to change the vehicle height at the front or rear of the vehicle body, so that when moving from a flat road surface to an uphill or downhill during vehicle travel, the vehicle Visibility in front of or behind can be improved.

DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a plan view showing an arrangement configuration of four wheels in a vehicle such as an automobile, an independent suspension type suspension device for each wheel, and a suspension control device for controlling the expansion / contraction operation of each suspension device, and FIG. The side view of is shown. FIG. 3 shows an example of the structure of the suspension device, and FIG. 4 shows the configuration of the control system of the suspension control device. FIG. 5 shows an example of the travel path of the vehicle, and FIG. 6 shows a flowchart showing an example of the control of the suspension control device.

  1 and 2, reference numerals 11L and 11R in the vehicle 10 indicate left and right front wheels, and reference numerals 12L and 12R indicate left and right rear wheels. In each figure, it is assumed that the direction indicated by the arrow A is the traveling direction of the vehicle 10, and the travel path along which the vehicle 10 travels follows the arrow A. The driver's line of sight (drivers view) driving the traveling vehicle 10 is directed in the direction of arrow A.

  In the vehicle 10, a suspension device 13 is provided between the axle portions of the four wheels 11 </ b> L, 11 </ b> R, 12 </ b> L, and 12 </ b> R and the vehicle body of the vehicle 10. Each of the four suspension devices 13 is provided for a corresponding wheel and has a function of independently suspending the corresponding wheel. The four suspension devices 13 are so-called active suspension devices and basically have the same structure and function. The structure and function of each suspension device 13 to which the active suspension control is applied is already known (for example, JP-A-2006-213119).

  FIG. 3 shows a structural example of the suspension device 13. The suspension device 13 normally includes a coil spring 21 that absorbs vibration and shock between the vehicle body and the wheels, and a shock absorber 22 that generates a damping force by oil flow resistance. The coil spring 21 is disposed on the outer periphery of the cylinder tube 23 and is supported on the vehicle body side and the wheel side via an upper spring seat 24 and a lower spring seat 25. The shock absorber 22 includes the above-described cylinder tube 23 that is positioned on the lower side and filled with oil, and a piston rod 26 that is positioned on the upper side and is inserted and fitted in the cylinder tube 23 so as to be movable forward and backward. The lower end of the cylinder tube 23 is coupled to the wheel side via a suspension arm (not shown), and the upper end of the piston rod 26 is coupled to the vehicle body side together with the upper spring seat 24.

  The suspension device 13 having the above-described structure includes a lifting adjustment mechanism 27. The lifting adjustment mechanism 27 is provided on the upper spring seat 24 and is composed of a base member 28 and an annular piston 29. The base member 28 has an annular cylinder hole 30 and is directly fixed to the vehicle body side together with the piston rod 26. The annular piston 29 is slidably fitted into the cylinder hole 30 of the base member 28 to form an operation chamber 31 between the annular piston 29 and the cylinder hole 30. In the lifting adjustment mechanism 27 of the suspension device 13, the hydraulic pressure is supplied / discharged from the external hydraulic supply / discharge device 41 to the working chamber 31 via the supply / discharge port 32, and the hydraulic pressure is appropriately controlled according to the conditions, The axial length of the suspension device 13 is adjusted, the vehicle body is moved up and down, and the height position of the vehicle body is adjusted appropriately.

  Returning to FIG. 1, the four suspension devices 13 attached to each of the four wheels 11L, 11R, 12L, and 12R are preferably provided in an independent state from the hydraulic supply / discharge device 41 through the hydraulic supply / discharge tube 42. Hydraulic pressure is supplied and discharged appropriately. In the case of the present embodiment, in particular, the front two wheels 11L, 11R and the rear two wheels 12L, 12R are moved up and down as a set, and the height of the front part of the vehicle body or the rear part of the vehicle body is adjusted. Control of the operation of the hydraulic supply / discharge device 41 is performed based on a control command signal from the control device 51.

  The control device 51 is an in-vehicle computer. In the suspension control device according to the present embodiment, as shown in FIG. 4, a tilt state change information extraction unit 52 is provided on the input side of the control device 51, and the hydraulic supply / discharge device 41 and the above-described hydraulic supply / discharge device 41 are provided on the output side. The four suspension devices 13 are provided.

  The inclination state change information extraction unit 52 has a function of extracting information related to a change in the inclination state of the planned traveling road surface in the traveling direction A of the vehicle 10. The inclination state change information extraction unit is configured using, for example, a navigation device mounted on the vehicle 10 or an acceleration sensor that is originally installed in the vehicle 10 for an airbag device or the like. A front camera can also be used.

  According to the navigation device, the traveling direction A of the vehicle 10 is based on road information and terrain information (land height information) included in the equipped map information, and current traveling position information of the vehicle 10 obtained by GPS or the like. It is possible to extract information relating to the change in the inclination state of the scheduled road surface. Further, according to the acceleration sensor, the acceleration state related to the traveling of the vehicle 10 changes according to the inclination of the road surface on which the vehicle 10 is traveling. For example, a flat traveling road, an uphill starting traveling road, an uphill traveling road, a downhill starting traveling road, a downhill traveling road, and the like have different acceleration states related to traveling. Therefore, if information relating to acceleration output from the acceleration sensor is used in a pattern, information relating to a change in the slope state of the road surface of the traveling road on which the vehicle 10 is actually traveling can be extracted.

  Further, in the control device 51 that realizes the suspension control device according to the present embodiment, the lifting / lowering operation based on the expansion / contraction operation of the suspension device 13 described above is controlled, and the height of a predetermined portion in the vehicle body of the vehicle 10 is appropriately set according to the condition. A vehicle height changing means 51A for changing is provided. In the case of this embodiment, the vehicle height changing means 51A is based on information related to the change in the inclination state given from the inclination state change information extraction unit 52. The suspension device 13 of 11L, 11R or the rear two wheels 12L, 12R is actuated to control the raising / lowering operation, thereby changing the vehicle height of the vehicle body front portion or the vehicle body rear portion.

  FIG. 5 shows an example of a traveling path assuming an inclined state of the road surface of the traveling path on which the vehicle 10 is to travel. It is assumed that the vehicle 10 is initially traveling leftward at the position P1. In this traveling road, there are three flat road surfaces 61, 63, 65, an uphill 62, and a downhill 64. When shifting from the flat road surface 61 to the uphill 62, when shifting from the flat road surface 63 at the top to the downhill 64, it is necessary to secure a forward field of view in the respective regions 66 and 67. That is, for example, when shifting from the flat road surface 61 to the uphill 62, the vehicle body front portion of the vehicle 10 so that the field of view (preferably the driver's view) above the uphill 62 is widened immediately before the transition to the uphill 62. It is desirable to increase the vehicle height (or lower the vehicle height at the rear of the vehicle body). Further, for example, when shifting from the flat road surface 63 to the downhill 64, the vehicle body front portion of the vehicle 10 is widened so that the field of view (preferably the driver's view) below the downhill 64 is expanded immediately before the downhill 64 is transferred. It is desirable to reduce the vehicle height (or increase the vehicle height at the rear of the vehicle body). In the above case, the change in the inclination state of the front road surface on which the vehicle 10 is traveling is extracted by the inclination state change information extraction unit 52, and the control device 51 uses the data relating to the change in the inclination information to The operation of the supply / discharge device 41 is controlled, and the operation of each lifting mechanism of the suspension device 13 is adjusted, so that the height of the vehicle is adjusted appropriately.

  Next, with reference to the flowchart of FIG. 6, the vehicle height adjustment will be described based on the vehicle height changing means 51 </ b> A provided in the control device 51. The vehicle height changing means 51A controls the elevation operation of each of the four suspension devices 13 under a predetermined condition via the hydraulic supply / discharge device 41, and controls the height of the vehicle body front portion or vehicle body rear portion of the vehicle 10. change.

  In the first step S11, the output signal of the tilt state change information extraction unit 52 is acquired. In the next step S12, it is determined whether or not there is a change in the inclination state of the road surface of the travel destination based on the acquired output signal. When there is no change in the slope state of the road surface of the travel destination, the vehicle height of the vehicle 10 is maintained as it is (step S13), and the process returns to step S11. When there is a change in the inclined state of the road surface of the travel destination, the control shifts to changing the vehicle height of the vehicle 10.

  In the control for changing the vehicle height of the vehicle, it is first determined whether or not the vehicle is uphill (step S14). If it is determined in step S14 that the vehicle is going uphill, control is performed to increase the height of the front portion of the vehicle body (or control to decrease the height of the rear portion of the vehicle body) (step S15). Thereafter, the control for changing the vehicle height is terminated. Whether or not it is an uphill is determined based on the inclination angle information by preparing an inclination reference for the uphill in advance using, for example, the inclination angle information. An arbitrary reference can be prepared for the inclination reference.

  If NO in step S14, that is, if it is determined not to be an uphill, it is next determined whether or not it is a downhill (step S16). If it is determined in step S16 that the vehicle is downhill, control is performed to reduce the height of the front part of the vehicle body (or control to increase the height of the rear part of the vehicle body) (step S17). Thereafter, the control for changing the vehicle height is terminated. If NO in determination step S16, the control is terminated without controlling anything as erroneous information or the like. Whether or not the vehicle is a downhill is determined based on the inclination angle information by preparing an inclination reference for downhill in advance using, for example, inclination angle information. An arbitrary reference can be prepared for the inclination reference.

  In the above-described process of changing the vehicle height, during traveling on the uphill 62 or traveling on the downhill 64, for example, the height of the vehicle body portion whose height has been changed is set. It is also desirable to control to gradually return to the height before the change so as to be parallel to the traveling road surface.

  In the above-described process of changing the vehicle height, the vehicle height change for securing the vehicle front view at the time of the transition from the flat road surface 61 to the uphill 62 or the transition from the flat road surface 63 to the downhill 64 is performed. Similarly, the control process for changing the vehicle height is established even when the vehicle is moving from the uphill 62 to the flat road surface 63 or when the vehicle is moving from the downhill 64 to the flat road surface 65. Of course you can.

  The configurations, shapes, sizes, and arrangement relationships described in the above embodiments are merely schematically shown to the extent that the present invention can be understood and implemented, and the numerical values and the compositions (materials) of the respective components Is just an example. Therefore, the present invention is not limited to the described embodiments, and can be variously modified without departing from the scope of the technical idea shown in the claims.

  The vehicle suspension control apparatus according to the present invention changes the height of the front part of the vehicle body or the rear part of the vehicle body in accordance with a change in the inclination of the traveling road surface in an automobile including four wheels that are independently suspended by an active suspension device, and Or it is used to secure the rear view.

FIG. 2 is a plan view conceptually showing the outline of a vehicle such as a four-wheeled vehicle, and includes an arrangement configuration of four wheels, an independent suspension type suspension device for each wheel, and a suspension control device that controls expansion and contraction operations of each suspension device. It is a top view which shows a layout. It is a side view of the vehicle shown in FIG. It is a fragmentary sectional view showing an example of the structure of a suspension device. It is a figure which shows the structure of the control system of the suspension control apparatus of the vehicle which concerns on this invention. It is a figure which shows an example of the traveling path of a vehicle. It is a flowchart which shows an example of control of the suspension control apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle 11L, 11R Front wheel 12L, 12R Rear wheel 13 Suspension device 21 Coil spring 22 Shock absorber 23 Cylinder tube 26 Piston rod 27 Lifting adjustment mechanism 28 Base member 29 Annular piston 30 Cylinder hole 31 Working chamber 41 Hydraulic supply / exhaust device 51 Control device 51A Vehicle height change means 52 Inclination state change information extraction unit 61, 63, 65 Flat road surface 62 Uphill 64 Downhill

Claims (5)

Four wheels comprising two front wheels and two rear wheels that support the vehicle body, and provided on each of the four wheels, the vehicle height of the vehicle body corresponding to the positions of the two front wheels and the two rear wheels can be independently changed 4 In a vehicle suspension control device comprising one suspension device and control means for operating the suspension device to arbitrarily change the vehicle height corresponding to each of the four suspension devices,
Inclination state change information extracting means for extracting information related to a change in the inclination state of the planned road surface in the traveling direction of the vehicle;
The front or rear of the vehicle body is operated by operating the suspension device of the front two wheels or the rear two wheels so that the field of view regarding the inclined road surface is expanded based on the information relating to the change in the inclination state given from the inclination state change information extracting means. Vehicle height changing means for changing the vehicle height,
A suspension control device for a vehicle, comprising:   Whether the vehicle height changing means increases the vehicle height of the front two wheels when the information related to the change in the inclination state given from the inclination state change information extracting means determines that the planned road surface is uphill. The vehicle suspension control device according to claim 1, wherein the vehicle height is changed to lower the vehicle height of the rear two wheels.   Whether the vehicle height changing means lowers the vehicle height of the front two wheels when the information related to the change in the inclination state given from the inclination state change information extracting means determines that the planned road surface is downhill. The vehicle suspension control device according to claim 1, wherein the vehicle height is changed so as to increase the vehicle height of the rear two wheels.   2. The vehicle suspension control device according to claim 1, wherein the inclination state change information extracting means is configured based on a navigation device mounted on the vehicle.   2. The vehicle suspension control apparatus according to claim 1, wherein the tilt state change information extracting means is configured using an acceleration sensor mounted on the vehicle.

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