JP2004299644A - Vehicle height adjustment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower the height of the whole of a vehicle and to enhance vehicle turnability by lowering the vehicle height of a turning inner wheel during turning traveling. <P>SOLUTION: When a degree of curving of a road during approaching is a set level or high (when the determination at S6 is YES), target vehicle height of the turning inner wheel is determined based on lateral acceleration in the case of traveling the road and a vehicle height adjustment starting timing is determined based on a traveling speed at the present time, a distance from the present point to the vehicle height adjustment completion target point and a time required for the vehicle height adjustment (S7). When it is arrived at the starting timing, the vehicle height adjustment starting instruction is outputted from a navigation system to a suspension ECU (S9). In the suspension device, the vehicle height of the turning inner wheel is lowered by the control of the fluid pressure control part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle height adjustment device that adjusts a vehicle height during turning of a vehicle.
[0002]
[Prior art]
Patent Literature 1 describes that the roll is suppressed by adjusting the vehicle height during turning.
[0003]
[Patent Document 1]
Japanese Patent No. 311504
[0004]
Problems to be Solved by the Invention, Means for Solving Problems, and Effects
It is an object of the present invention to reduce the vehicle height of the inner wheel during turning to lower the vehicle height of the entire vehicle, thereby achieving running stability. This problem is solved by configuring the vehicle height adjusting device to have the following configurations. Each mode is described in the same manner as in the claims, divided into sections, each section is numbered, and described in a form in which the numbers of other sections are cited as necessary. This is for the purpose of facilitating the understanding of the technology described in this specification, and the technical features and their combinations described in this specification should not be construed as being limited to the following sections. Absent. In addition, when a plurality of items are described in one section, it is not always necessary to adopt all items together, and it is also possible to take out and adopt only some items.
[0005]
Of the following items, (1) corresponds to claim 1, and (9) corresponds to claim 2.
[0006]
(1) A vehicle height adjusting device provided for each wheel of a vehicle and capable of adjusting a relative height of a vehicle body side member with respect to a wheel side member,
A vehicle height adjusting device, comprising: a turning inner wheel vehicle height adjusting unit for lowering the relative height of the vehicle body side member with respect to the wheel side member at the turning inner wheel during turning of the vehicle, as compared to when the vehicle is not turning.
In the vehicle height adjusting device according to the present mode, the relative height (hereinafter, simply referred to as the vehicle height) of the vehicle body-side member to the wheel-side member of the turning inner wheel during turning is lower than when the vehicle is not turning.
During turning, the vehicle is tilted in such a direction that the vehicle height on the turning outer wheel side decreases due to centrifugal force. In this case, the inclination of the vehicle can be reduced even if the height of the turning outer wheel is increased. However, in the vehicle height adjusting device described in this section, the vehicle height of the turning inner wheel is reduced, and Does not increase the vehicle height. In addition, it does not mean that the height of the turning outer wheel is increased and the vehicle height of the turning inner wheel is reduced. Therefore, the vehicle height of the entire vehicle can be reduced as compared with the case where the vehicle height of the turning outer wheel is increased or the vehicle height of the turning outer wheel is increased and the vehicle height of the turning inner wheel is reduced. As a result, the stability can be improved, and the turning performance can be improved.
(2) a road condition information acquisition device that acquires road condition information including information representing the shape of the road on which the vehicle is to travel,
The turning inner wheel vehicle height adjustment unit is configured such that the road state information acquired by the road state information acquisition device has a curved road shape, and that the degree of curvature is equal to or greater than a set level. The vehicle height adjustment device according to (1), further including a vehicle height adjustment unit that reduces a vehicle height of the turning inner wheel when the vehicle is represented.
(3) a road condition information acquisition device for acquiring road condition information including information representing the shape of the road on which the vehicle is to travel,
The turning inner wheel vehicle height adjusting unit may be configured such that when the road condition information acquired by the road condition information acquiring device indicates that the state of the road surface is substantially flat and not inclined in the width direction, The vehicle height adjusting device according to the above mode (1) or (2), including a road surface condition-adjustable vehicle height adjusting section for reducing the height.
In the vehicle height adjusting device described in this section, when the degree of curvature of the approaching road is equal to or higher than the set level, the vehicle height of the turning inner wheel is reduced.
The degree of curvature can be represented by a radius of curvature, represented by a curvature, or represented by a value that becomes larger as the curvature is larger and the radius of curvature is smaller. The degree of bending can also be expressed by the magnitude of the lateral acceleration estimated to occur when the vehicle travels on the road, the magnitude of the yaw rate, or by the estimated operation amount of the steering member by the driver. it can.
Further, when the road surface is flat (for example, on a pavement road) and is not inclined in the width direction, the turning inner wheel vehicle height adjustment may be performed. It is not always desirable to perform the vehicle height adjustment when the road surface is in a state of large unevenness or in a state of being inclined in the lateral direction (when there is a bank). Therefore, the control for lowering is not performed.
When the road has a curved shape, the vehicle height adjustment of the turning inner wheel may be performed irrespective of the degree of the curve or the state of the road surface.
(4) a road condition information acquisition device that acquires road condition information including information representing the shape of the road on which the vehicle is to travel,
The turning inner wheel vehicle height adjustment unit is at least one of a degree of curvature of a road to be traveled represented by the road state information acquired by the road state information acquisition device and an estimated traveling state of the vehicle when traveling on the road. The vehicle height adjusting device according to any one of (1) to (3), including a target vehicle height determining unit that determines a target vehicle height of the turning inner wheel based on the target vehicle height.
For example, the target vehicle height of the turning inner wheel can be made lower when the degree of curve of the road is high than when it is low, and lower when the estimated traveling state exceeds the set state than when it does not.
The estimated traveling state can be represented by a traveling speed, a roll state, a yaw rate, a lateral acceleration, or the like of the vehicle, or can be represented by a centrifugal force applied to the vehicle. The running states of these vehicles can be estimated based on the degree of curvature of the road.
(5) The target vehicle height determination unit sets the target of the turning inner wheel based on the estimated traveling speed estimated based on the degree of curvature of the road to be traveled represented by the road state information acquired by the road state information acquisition device. The vehicle height adjusting device according to item (4), including a target vehicle height determining unit corresponding to a traveling speed that determines a vehicle height.
(6) The target vehicle height determination unit determines the target vehicle of the turning inner wheel based on the centrifugal force estimated based on the degree of curvature of the road to be traveled indicated by the road state information acquired by the road state information acquisition device. The vehicle height adjustment device according to the above mode (4) or (5), including a centrifugal force target vehicle height determination unit for determining a height.
When the vehicle travels on a curved road, the centrifugal force (corresponding to the lateral acceleration) applied to the vehicle increases as the degree of curvature increases and as the traveling speed increases. The traveling speed generally decreases as the degree of curvature increases. Therefore, the magnitude of the centrifugal force can be estimated based on the degree of curvature of the road. Also, as the centrifugal force applied to the vehicle increases, the vehicle height on the turning outer wheel side decreases, and the inclination in the roll direction increases. Therefore, it is reasonable to make the target vehicle height of the turning inner wheel lower when the centrifugal force is large than when it is small.
Further, as described above, based on the centrifugal force, the vehicle height of the turning outer wheel when traveling on the curved road can be estimated. In this sense, it can be considered that the target vehicle height of the turning inner wheel is determined based on the vehicle height of the turning outer wheel estimated when the vehicle travels on the road. The target vehicle height of the turning inner wheel may be higher, lower, or substantially the same as the vehicle height of the turning outer wheel. The height of the turning inner wheel may be lower than when the vehicle is not turning.
(7) (a) a road condition information acquisition device for acquiring road condition information including information representing a shape of a road on which the vehicle is to travel, and (b) a traveling condition detection for detecting a traveling condition including a traveling speed of the vehicle. Equipment and
Before the turning inner wheel vehicle height adjustment unit, when the shape of the road to be traveled represented by the road condition information acquired by the road condition information acquiring device has a curved shape, before reaching the curved portion The vehicle height according to any one of (1) to (6), wherein the vehicle height adjustment of the turning inner wheel is started from at least a timing determined based on a traveling speed of the vehicle and a curved shape of the road. Adjustment device.
Based on the curved shape of the road, a point where it is desirable that the vehicle height of the turning inner wheel is reduced to the target vehicle height, that is, a point where it is desirable that the turning inner wheel vehicle height adjustment is completed is known. Further, the time required for adjusting the vehicle height can be determined based on the actual vehicle height of the turning inner wheel and the target vehicle height. On the other hand, based on the traveling state including the traveling speed of the vehicle at the present time, the time required for the vehicle to reach the turning inner wheel vehicle height adjustment completion point can be known. Therefore, based on these, it is possible to know the time when the vehicle height adjustment of the turning inner wheel should be started.
Further, a vehicle height adjustment start point at which vehicle height adjustment is started based on the distance between the local point and the vehicle height adjustment completion point and the distance traveled by the vehicle within the time required for vehicle height adjustment is determined. The vehicle height adjustment may be started when the vehicle height adjustment start point is reached. In this case, the vehicle height adjustment start point is obtained instead of the vehicle height adjustment start time, but obtaining the start time and obtaining the start point are substantially the same.
The running state of the vehicle includes the running speed, acceleration, deceleration, and the like of the vehicle. The acceleration, deceleration, and the like of the vehicle can be detected by an acceleration sensor or the like, but can also be obtained based on the operation state of the accelerator operation member, the operation state of the brake operation member, and the like.
[0007]
(8) a fluid chamber provided for each wheel and provided between the wheel side member and the vehicle body side member;
A fluid passage connected to each of the fluid chambers, the fluid passage including a plurality of individual passages and a common passage;
An individual valve provided in each of the plurality of individual passages,
An opening valve provided in the common passage, and provided between the common passage and the outside air;
A compressor connected to the common passage;
An electric motor that drives the compressor;
A vehicle height adjustment unit for electrically controlling the release valve, the individual valve and the electric motor;
The vehicle height adjusting device according to any one of the above items (1) to (7), including:
The vehicle height is adjusted by adjusting the amount of the fluid in the fluid chamber provided on each wheel side and adjusting the pressure of the fluid. Increasing the amount of fluid in the fluid chamber and increasing the pressure increases the vehicle height, and decreasing the amount of fluid and decreasing the pressure decreases the vehicle height.
The open valve and the individual valve are electromagnetic valves that can be switched at least between an open state and a closed state by controlling the supply current to the solenoid. Or an electromagnetic flow control valve that permits the flow of the fluid at a flow rate corresponding to the above.
When adjusting the vehicle height of all the wheels in common, the individual valves corresponding to the respective fluid chambers are kept open. When the vehicle height at each wheel is commonly increased, the compressor is operated by the electric motor. The high-pressure fluid of the compressor is supplied to all the fluid chambers via a common passage and respective individual passages. When the vehicle height of each wheel is reduced in common, the release valve is opened. The fluid in each of the fluid chambers is released to the atmosphere through respective individual passages, common passages, and release valves. When the vehicle height of each wheel is adjusted independently, the individual valves are individually controlled.
For example, a case where the vehicle height of the turning outer wheel is increased during turning so that the vehicle has a posture in which the floor surface is substantially parallel to the road surface (hereinafter, referred to as a substantially horizontal posture). Then, the vehicle height of the turning outer wheel is increased to the target vehicle height by operating the compressor in a state where the individual valve corresponding to the turning outer wheel is opened and the individual valve corresponding to the turning inner wheel is closed.
Also, when the vehicle height of the turning outer wheel is increased and the vehicle height of the turning inner wheel is reduced so that the posture of the vehicle becomes substantially horizontal, first, the vehicle is provided in an individual passage of the fluid chamber of the turning outer wheel. With the individual valves (hereinafter simply referred to as individual valves of the turning outer wheel) opened and the individual valves of the inner turning wheel closed, the compressor operates to raise the vehicle height of the turning outer wheel to the target vehicle height. . Thereafter, the vehicle height of the turning inner wheel is lowered to the target vehicle height by closing the individual valve of the turning outer wheel and opening the open valve with the individual valve of the turning inner wheel being open.
Further, when the vehicle height of the four wheels is lowered to make the vehicle attitude substantially horizontal, the individual valves corresponding to the turning inner wheel are opened and the individual valves corresponding to the turning outer wheel are closed. By opening the release valve, the vehicle height of the turning inner wheel is lowered, and then the individual valves of all the wheels are opened to lower the vehicle height of the entire vehicle. In this case, if a dryer device (including a throttle or the like) is provided in the common passage, the flow rate of the fluid flowing through the common passage is restricted by the dryer device. In the case and the case where the vehicle height of the turning inner wheel is reduced, the time required for the vehicle height adjustment becomes longer when the vehicle heights of all the wheels are reduced.
On the other hand, if the vehicle height of the turning inner wheel is reduced so that the vehicle attitude becomes substantially horizontal, the vehicle height of the turning inner wheel may be reduced.
In general, when the vehicle height is set lower than when the vehicle height is set higher, the time required when the vehicle height adjustment amount is the same is shorter.
Therefore, if the posture of the vehicle during turning is made substantially horizontal by lowering the height of the turning inner wheel, the time required for adjusting the vehicle height can be shortened. If the time required for the vehicle height adjustment becomes shorter, the vehicle height of the turning inner wheel can be quickly brought closer to the target vehicle height, and control delay can be suppressed.
Also, as described above, when the vehicle height adjustment is started before the vehicle enters the curved portion of the road and the vehicle height adjustment is completed when the vehicle reaches the turning inner wheel vehicle height adjustment completion point, the vehicle height adjustment is performed. , The start time can be accurately determined, and the vehicle height adjustment can be completed as scheduled. Since the time required to adjust the vehicle height is reduced, the probability that the running speed of the vehicle changes or the vehicle stops during the vehicle height adjustment is reduced. This is because the probability of running increases.
[0008]
(9) A vehicle height adjusting device provided for each wheel of the vehicle and capable of adjusting a relative height of the vehicle body side member with respect to the wheel side member,
A road condition information acquisition device for acquiring road condition information including information representing the shape of the road on which the vehicle is to travel,
When the road condition information acquired by the road condition information acquisition device indicates that the shape of the road to be traveled has a curved shape, the relative height of the vehicle body-side member with respect to the wheel-side member in the turning inner wheel, A turning inner wheel vehicle height adjustment unit that lowers from a timing determined based on at least the traveling speed of the vehicle before the vehicle reaches a curved shape portion of the road;
A vehicle height adjustment device comprising:
The technical features described in any one of the above items (1) to (8) can be adopted in the vehicle height adjusting device described in this item.
(10) A vehicle height adjusting device that is provided for each wheel of a vehicle and that can adjust a relative height of a vehicle body side member with respect to a wheel side member, respectively.
A road state information acquisition device that acquires information representing the shape of the road on which the vehicle is to travel,
When the road condition information acquired by the road condition information acquisition device indicates that the shape of the road to be traveled has a curved shape, the relative height of the vehicle body-side member with respect to the wheel-side member in the turning inner wheel, A turning inner wheel vehicle height adjustment unit that adjusts based on the state of curvature of the road;
A vehicle height adjustment device comprising:
In the vehicle height adjusting device described in this section, the vehicle height of the turning outer wheel is not adjusted, and the vehicle height of the turning inner wheel is adjusted.
The technical features described in any one of the above items (1) to (9) can be adopted in the vehicle height adjusting device described in this item.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
A vehicle height adjusting device according to an embodiment of the present invention will be described in detail with reference to the drawings.
In FIG. 1, 10 is a navigation system, and 12 is a suspension system.
The navigation system 10 includes an information processing device 20, a current position acquisition device 22, a traveling state detection device 24, a storage device 26, a display device 28, an audio output device 30, and the like. The suspension system 12 includes a suspension ECU 32, a vehicle speed sensor 34, It includes a vehicle height sensor 36, a fluid chamber 38, a fluid pressure control unit 42, and the like.
[0010]
In the navigation system 10, the current position acquisition device 22 includes a reception device that receives information from artificial satellites, beacons, and the like, and acquires the current position of the vehicle based on the information. The traveling state detecting device 24 includes a steering angle sensor or a yaw rate sensor, a traveling speed sensor, and the like, and a geomagnetic sensor, and acquires traveling states such as a traveling speed and a traveling direction based on these. Further, the traveling state detection device 24 may include an acceleration sensor. According to the acceleration sensor, the state of acceleration / deceleration of the vehicle can be known.
The storage device 26 stores map information, information representing the shape of a road, and the like.
The display device 28 includes a display, and displays the state of the road on which the vehicle travels, and displays that the vehicle height is being adjusted. The audio output device 30 includes a speaker and outputs audio.
The information processing device 20 is mainly composed of a computer, and includes a planned road shape acquisition unit 46, a vehicle height adjustment command unit 48, and the like. The planned traveling road state acquisition unit 46 acquires information indicating the state of the road on which the vehicle travels before the set time elapses based on, for example, map information, the current position, the traveling state, and the like. A vehicle height adjustment command is created and output based on the road shape, running state, and the like.
[0011]
In the suspension device 12, the vehicle speed sensor 34 detects the traveling speed of the vehicle, and the vehicle height sensor 36 is provided for each wheel, and detects a change in the relative height of the vehicle body-side member with respect to the wheel-side member. It is.
The suspension ECU 32 is mainly composed of a computer, and includes a vehicle height adjusting unit 49. The vehicle height adjustment unit 49 controls the fluid pressure control unit 42 based on commands and information supplied from the navigation system 10.
[0012]
The fluid pressure control unit 42 will be described with reference to FIG. Air chambers 50a to 50d as fluid chambers are provided between the wheel side member and the vehicle body side member corresponding to each of the front, rear, left and right wheels of the vehicle. A fluid passage 52 is connected to each of the air chambers 50a to 50d. The fluid passage 52 includes a common passage 54 and individual passages 56a to 56d. The common passage 54 is provided with a dryer device 58 (including a throttle or the like) and is connected to the compressor 60. Further, the air is exposed to the outside air through the opening valve 62. The compressor 60 is operated by driving the electric motor 64. The individual passages 56a to 56d are provided with individual valves 66a to 66d, respectively.
[0013]
The open valve 62 and the individual valves 66a to 66d are electromagnetic valves, and are switched between an open state and a closed state by turning ON / OFF a current supplied to the solenoid. The operating state of the compressor 60 is controlled by controlling the current supplied to the electric motor 64. By controlling the individual valves 66a to 66d, the release valve 62, and the electric motor 64, the amount of air in the fluid chambers 50a to 50d provided for each wheel is controlled and the air pressure is controlled. Height is adjusted. In the present embodiment, the fluid pressure control unit 42 includes the individual valves 66a to 66d, the release valve 62, the electric motor 64, and the like.
Reference numerals 36a to 36d denote vehicle height sensors. The vehicle height sensors 36a to 36d are provided for each wheel.
[0014]
When the vehicle heights of the four wheels are commonly adjusted, the release valve 62 and the electric motor 64 are controlled while the individual valves 66a to 66d are kept open. By the operation of the compressor 60, high-pressure air is supplied to each of the fluid chambers 50a to 50d through the common passage 54 and the individual passages 56a to 56d to increase the vehicle height. In addition, by opening the open valve 62, the air in the fluid chambers 50a to 50d is released to the outside air via the individual passages 56a to 56d, the common passage 54, and the open valve 62, thereby lowering the vehicle height.
On the other hand, when the vehicle height is adjusted for each wheel, the individual valves 62a to 62d are individually controlled to be in the open state and the closed state, respectively.
[0015]
In the present embodiment, when the road to be traveled is curved, the individual valve corresponding to the turning inner wheel is opened when traveling on the curved road, and the individual valve corresponding to the turning outer wheel is opened. By setting the closed state and opening the open valve 62, the vehicle height of the turning inner wheel is reduced. The adjustment of the vehicle height of the turning inner wheel is performed when the degree of curvature of the road to be traveled is equal to or higher than the set level. This is because when the degree of curvature of the road is gentle, it is not necessary to adjust the vehicle height. The degree of curvature can be represented by a curvature, a radius of curvature, or a number that increases as the curvature increases and the radius decreases. Also, the yaw rate estimated to be generated when the vehicle travels on the road can be represented by an operation angle of the steering member by the driver.
[0016]
Further, the target vehicle height of the turning inner wheel is determined based on the degree of curvature of the road. The centrifugal force (lateral acceleration) applied to the vehicle is estimated based on the degree of curvature of the road, and the vehicle height of the turning inner wheel is determined based on the centrifugal force. For example, the turning radius is determined based on the degree of curvature, the traveling speed when traveling on the curved road is determined, and the lateral acceleration (centrifugal force) applied to the vehicle is estimated based on these. Then, when the estimated centrifugal force is large, the target vehicle height is made lower than when it is small.
Whether the inner turning wheel is the right wheel or the left wheel is determined by the direction of the curve of the road.
[0017]
Further, the start timing of the vehicle height adjustment is determined based on the traveling state including the degree of curvature of the road, the traveling speed of the vehicle, and the like. When the start timing is reached, vehicle height adjustment is started.
The determination of the start timing will be described with reference to FIG.
(A) Based on the curved state of the road, a point where vehicle height adjustment is desired to be completed, that is, a vehicle height adjustment completion target point is determined.
(B) The time Treq required for the vehicle height adjustment is determined based on the current vehicle height of the turning inner wheel and the target vehicle height.
Also, based on (c) the distance from the local point to the vehicle height adjustment completion target point, the running speed of the vehicle, acceleration / deceleration, etc., the total traveling time required from the local point to the vehicle height adjustment completion target point is calculated. Understand.
(D) By subtracting the time required for vehicle height adjustment Treq from the total running time, the vehicle height adjustment start time, that is, the vehicle height adjustment start timing is determined.
[0018]
In the information processing unit 20 of the navigation system 10, a vehicle height adjustment command output program represented by the flowchart in FIG. 3 is executed at predetermined set times.
In step 1 (hereinafter, abbreviated as S1; the same applies to other steps), information indicating the shape of the road at the local point, information indicating the shape of the road running before the set time elapses, Information or the like representing the traveling state is acquired. In S2, it is determined whether or not the turning inner wheel vehicle height adjustment command has already been output, and in S3, it is determined whether or not the curve has ended based on the information indicating the state of the road at the local point. If it is determined that the curve has ended, in S4, a turning inner wheel vehicle height adjustment release command is output to the suspension ECU 32. In S5, the vehicle height of the turning inner wheel is controlled by the display device 28 and the sound output device 30. The display indicating that the vehicle is in the low state is deleted, and an announcement that the vehicle height adjustment to restore the vehicle height is started is performed once. The execution of S4 and S5 can be referred to as turning inner wheel vehicle height adjustment end processing.
If the curve has not ended, the turning inner wheel vehicle height adjustment end processing is not performed.
Whether or not the local point is the point where the curve ends is determined based on the information stored in the storage device 26, or the degree of curvature of the road during the set distance including the local point is extremely high. It can be determined based on whether or not it is small (when it has a shape that extends substantially linearly).
[0019]
If the turning inner wheel vehicle height adjustment command is not currently output, that is, if the turning inner wheel vehicle height adjustment is not performed, in S6, is the shape of the road to be traveled a curved shape? Is detected. It is detected whether the degree of bending is equal to or higher than the set level.
If the degree of curvature is equal to or higher than the set level, it is determined in S7 whether the wheel corresponding to the turning inner wheel is the right wheel or the left wheel according to the direction of the curvature. Further, as described above, the target vehicle height of the turning inner wheel is determined based on the centrifugal force determined based on the degree of bending and the like, and the start timing is determined. In S8, it is determined whether the start timing has come. The start timing is waited. If the start timing is reached, the determination in S8 is YES, and in S9, a turning inner wheel height adjustment command is output to the suspension ECU 32, and the target vehicle height, turning Information representing the inner ring is output. In S10, under the control of the display device 28 and the sound output device 30, an announcement that the vehicle height is to be lowered is made once, and the display indicates that the vehicle height of the inner wheel for turning is to be lowered.
[0020]
In the suspension ECU 32, a vehicle height adjustment program represented by a flowchart in FIG. 5 is executed. In S21 and S22, it is determined whether the received information is a vehicle height adjustment command or not, and whether the received information is a vehicle height adjustment cancellation command. If the command is a vehicle height adjustment command, the vehicle height adjustment is started based on the information transmitted from the navigation system 10 in S23. If the received information is a vehicle height adjustment release command, a process of returning the vehicle height to the original height is performed in S24. The height of the turning inner wheel is raised to the original height. If neither is the case, processing is performed according to the content of the received information.
[0021]
As described above, in the present embodiment, since the vehicle height of the turning inner wheel is reduced during the turning traveling, the vehicle height of the entire vehicle can be reduced and the vehicle can be in a substantially horizontal posture. As a result, it is possible to improve the contact property and the steering stability.
In addition, the height of the turning outer wheel is not raised and the height of the turning inner wheel is not lowered, but the height of the turning inner wheel is lowered, so that the time required for adjusting the vehicle height can be shortened and the control delay is suppressed. can do.
In addition, the vehicle height adjustment is started when the start timing before entering the curve is reached.However, since the time required for the vehicle height adjustment is short, the vehicle speed changes rapidly during the vehicle height adjustment. The probability of stopping or stopping is reduced, and the probability of completing the vehicle height adjustment as scheduled is increased. The vehicle height adjustment can be completed when reaching the turning inner wheel vehicle height adjustment completion point.
[0022]
In the above embodiment, the start timing is estimated based on the shape of the road and the traveling state, and the adjustment of the vehicle height is started from the time when the start timing is reached before the vehicle enters the curve. But doing so is not essential. The vehicle height adjustment may be started after entering a curve. Also in this case, since the time required for adjusting the vehicle height is short, the control delay can be suppressed accordingly. Further, the present embodiment is effective while traveling on a road such as an S-shaped road in which curved portions having opposite curved directions are continuous.
Further, in the above-described vehicle height adjustment command output program, S1, 2, 6 to 8 may be repeatedly executed until the start timing is reached. In this case, the start timing can be changed according to a change in the traveling speed of the own vehicle, and the start timing can be accurately estimated.
[0023]
Further, the starting point of the vehicle height adjustment may be obtained, and the vehicle height adjusting start timing may be obtained based on the starting point. The total distance therebetween is determined based on the local point and the vehicle height adjustment completion target point, and the traveling distance during the vehicle height adjustment time Treq is determined based on the traveling state. By subtracting the distance, you can find the starting point of height adjustment. Therefore, the vehicle height adjustment is started from the time when the vehicle height adjustment start point is reached, and the time when the vehicle height adjustment start point is reached is the vehicle height adjustment start timing.
Further, the fluid pressure control unit 42 may be based on hydraulic pressure instead of air.
The present invention can be embodied with various modifications and improvements based on the knowledge of those skilled in the art, in addition to the aspects described in [Problems to be Solved by the Invention, Problem Solving Means and Effects].
[Brief description of the drawings]
FIG. 1 is a diagram showing an entire vehicle height adjusting device according to an embodiment of the present invention.
FIG. 2 is a diagram showing a fluid pressure control unit of the vehicle height adjusting device.
FIG. 3 is a flowchart showing a vehicle height adjustment command program stored in a storage unit of an information processing device of the navigation system of the vehicle height adjustment device.
FIG. 4 is a diagram illustrating a method of determining a start timing of vehicle height adjustment in the information processing unit.
FIG. 5 is a flowchart illustrating a vehicle height adjustment program stored in a storage unit of a suspension ECU of the suspension device of the vehicle height adjustment device.
[Explanation of symbols]
42: fluid pressure control unit 46: scheduled road shape acquisition unit 48: vehicle height adjustment command unit 49: vehicle height adjustment unit

Claims (2)

A vehicle height adjustment device that is provided for each wheel of the vehicle and that can adjust the relative height of the vehicle body side member with respect to the wheel side member,
A vehicle height adjusting device, comprising: a turning inner wheel vehicle height adjusting unit for lowering the relative height of the vehicle body side member with respect to the wheel side member at the turning inner wheel during turning of the vehicle, as compared to when the vehicle is not turning. A vehicle height adjusting device that is provided for each wheel of the vehicle and that can adjust the relative height of the vehicle body side member with respect to the wheel side member,
A road condition information acquisition device for acquiring road condition information including information representing the shape of the road on which the vehicle is to travel,
When the road condition information acquired by the road condition information acquisition device indicates that the shape of the road to be traveled has a curved shape, the relative height of the vehicle body-side member with respect to the wheel-side member in the turning inner wheel, A vehicle height adjusting device, comprising: a turning inner wheel vehicle height adjusting unit that lowers the vehicle from a timing determined based on at least the traveling speed of the vehicle before the vehicle reaches a curved portion of the road.

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