JP2013043564A - Vehicle height adjusting method and vehicle height adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle height adjusting method and a vehicle height adjusting device, capable of controlling an attitude of a vehicle so that a dynamic balance such as maneuvering stability and ride comfort of the vehicle becomes optimal by adjusting a vehicle height, even when a person gets on and a cargo is loaded.SOLUTION: While changing any one wheel of the vehicle of arranging a vehicle height adjusting means capable of adjusting the vehicle height in at least one wheel, in a range of a frequency of 0-6 Hz by an excitation means, a change in a value of a wheel load of the vehicle whole wheels is measured by exciting in the vertical direction, a pitch roll transmission characteristic of the vehicle is set based on the frequency of excitation and the measured value of the wheel load of the respective wheels, and the vehicle height adjusting means is controlled so that a phase in the pitch roll transmission characteristic approaches 0 when the frequency is higher by 1 Hz than the frequency of becoming the peak of gain in the pitch roll transmission characteristic.

Description

  The present invention relates to a vehicle height adjusting device for a vehicle, and more particularly to a vehicle height adjusting method and a vehicle height adjusting device for adjusting a vehicle height so that a dynamic balance of the vehicle is optimized.

Conventionally, it is known that steering response and ride comfort are improved by adjusting the balance of the vehicle. There are vehicles equipped with a vehicle height adjustment device that includes a suspension that can adjust the vehicle height, such as an air suspension, and that automatically adjusts the posture of the vehicle body according to the riding state of the person and the loading state of the luggage.
Such a vehicle height adjusting device includes a vehicle height adjusting means for adjusting the vehicle height on the rear wheel side of the vehicle, and a front wheel for individually detecting the vehicle height on the front wheel side and the vehicle height on the rear wheel side. Side vehicle height detection means and rear wheel side vehicle height detection means, and the front wheel side vehicle height detected by the front wheel side vehicle height detection means and the rear wheel side vehicle height detection means detected by the rear wheel side vehicle height detection means. The vehicle height control means for controlling the vehicle in a horizontal state, the comparison means for comparing the vehicle height at the front and rear wheel positions of the vehicle controlled in the horizontal state with the standard vehicle height, and the vehicle height control means controlled in the horizontal state. Vehicle height correction means for correcting the vehicle height on the rear wheel side to be lower than the vehicle height on the front wheel side by a predetermined amount when it is determined that the vehicle height at the front and rear wheel positions of the vehicle is lower than the standard vehicle height. The attitude of the vehicle is automatically adjusted so that the irradiation position of the headlight is optimal.

Japanese Patent Laid-Open No. 11-32270

  However, the vehicle height adjusting device adjusts the vehicle height so that the irradiation angle of the headlight is constant, and maintains a dynamic balance of the vehicle while the vehicle is running. It is not a thing. In other words, the headlight illumination angle can be maintained constant, but control is not performed in consideration of variations in the load on the suspension caused by passengers or loading of luggage. Will run in a state where the load balance acting on the wheels is broken, for example, it will affect the running performance of the vehicle such as straight running stability, and will impair the steering stability performance and ride comfort for the driver .

  In order to solve the above-described problems, the present invention optimizes the dynamic balance of vehicle handling stability, ride comfort, and the like by adjusting the vehicle height, even when a person is on board or loads are loaded. Thus, a vehicle height adjustment method and a vehicle height adjustment device that can control the attitude of the vehicle are provided.

As an aspect of the vehicle height adjusting method for solving the above-described problem, a frequency of 0 to 6 Hz is applied to any one wheel of a vehicle provided with vehicle height adjusting means capable of adjusting the vehicle height on at least one wheel. Measure the change in the wheel load value of all the wheels by vibrating in the vertical direction while changing the frequency in the range of the vehicle pitch based on the vibration frequency and the measured wheel load value of each wheel. A roll transmission characteristic is set, and the vehicle height adjusting means is controlled so that the phase value in the pitch roll transmission characteristic approaches zero when the frequency is 1 Hz higher than the gain peak frequency in the pitch roll transmission characteristic. .
According to this aspect, at least one of the vehicles provided with the vehicle height adjusting means that can adjust the vehicle height is changed in frequency range of 0 to 6 Hz by the vibration means. Based on the change in the wheel load value at each wheel measured in response to vibration, the vehicle pitch roll transmission characteristics are set for the vibration, and the gain peaks in the pitch roll transmission characteristics. The vehicle balance can be optimized by controlling the vehicle height adjusting means so that the phase value of the pitch roll transfer function when the frequency is 1 Hz higher than the frequency approaches zero. In other words, by adjusting the vehicle height by at least one vehicle height adjusting means that enables the vehicle height to be adjusted in the vehicle, the balance of the vehicle, in other words, the center of gravity of the vehicle can be optimized, and the steering stability Improves performance and ride comfort.

Further, as another aspect of the vehicle height adjusting method for solving the above-described problem, a wheel load caused by vibration applied to all the wheels during traveling of the vehicle provided with a vehicle height adjusting means capable of adjusting the vehicle height on at least one wheel. The change in value is measured, the pitch roll transmission characteristic of the vehicle is set based on the vibration frequency and the measured wheel load value of each wheel, and the frequency is 1 Hz from the frequency at which the gain rolls in the pitch roll transmission characteristic. The vehicle height adjusting means is controlled so that the phase value in the pitch roll transmission characteristic when the height is high approaches zero.
According to this aspect, in addition to the above-described effect, the vehicle can be more accurately balanced because it is possible to vibrate either one of the front and rear wheels on one side of the vehicle with the vibration means to give a larger input to the vehicle. Can be optimized to improve steering stability and ride comfort.

Further, as another aspect of the vehicle height adjustment method for solving the above-described problem, a change in wheel load values of all the wheels during traveling of the vehicle provided with vehicle height adjustment means that enables vehicle height adjustment to at least one wheel. The pitch roll transmission characteristic of the vehicle is set based on the vibration frequency and the measured wheel load value of each wheel, and the frequency is 1 Hz higher than the frequency at which the gain rolls in the pitch roll transmission characteristic. The vehicle height adjusting means is controlled so that the phase value in the pitch roll transmission characteristics at that time approaches zero.
According to this aspect, in addition to the above effects, the vehicle is adjusted so that the balance of the vehicle is optimal during traveling of the vehicle, so that stable steering stability performance and good riding comfort can always be maintained.

Further, as a configuration of the vehicle height adjusting device that solves the above-described problem, a vehicle height adjusting means that is provided on at least one wheel of the vehicle and adjusts the vehicle height of the vehicle, and provided on all the wheels of the vehicle, the wheel of the vehicle is provided. The wheel load measuring means for measuring the load value, the vibration means for vibrating one wheel of the vehicle up and down while changing the frequency in the frequency range of 0 to 6 Hz, and the vibration frequency were measured. Pitch roll transmission characteristic setting means for setting the pitch roll transmission characteristic of the vehicle based on the wheel load value of each wheel of the vehicle, and pitch roll transmission when the frequency is 1 Hz higher than the frequency at which the gain peak in the pitch roll transmission characteristic is peaked. Vehicle height control means for controlling the vehicle height adjustment means so that the phase value in the characteristics approaches zero is adopted.
According to this configuration, at least one vehicle is provided with a vehicle height adjustment means that can adjust the vehicle height, and any one wheel of the vehicle is changed in the frequency range of 0 to 6 Hz by the vibration means. The pitch roll transmission characteristic of the vehicle with respect to the vibration is set based on the change in the wheel load at each wheel measured as a response to the vibration, and 1 Hz from the frequency at which the gain peak in the pitch roll transmission characteristic is obtained. The vehicle balance can be optimized by controlling the vehicle height adjusting means so that the phase value of the pitch roll transfer function when the partial frequency is high approaches zero. In other words, by adjusting the vehicle height by at least one vehicle height adjusting means that enables the vehicle height to be adjusted in the vehicle, the balance of the vehicle, in other words, the center of gravity of the vehicle can be optimized, and the steering stability Improves performance and ride comfort.

Further, as another configuration of the vehicle height adjusting device that solves the above problem, the vehicle height adjusting means that is provided on at least one wheel of the vehicle and adjusts the vehicle height of the vehicle, and is provided on all the wheels of the vehicle. Wheel load measuring means for measuring the wheel load value of the vehicle, vibration means for vibrating the two wheels on the front and rear sides of the vehicle up and down while changing the frequency in the frequency range of 0 to 6 Hz, the frequency of vibration, and measurement Pitch roll transmission characteristic setting means for setting the pitch roll transmission characteristic of the vehicle based on the wheel load value of each wheel of the vehicle, and the pitch when the frequency is higher by 1 Hz than the frequency at which the gain rolls in the pitch roll transmission characteristic Vehicle height control means for controlling the vehicle height adjustment means so that the phase value in the roll transmission characteristic approaches zero is adopted.
According to this configuration, in addition to the above-described effects, a larger input can be given to the vehicle by exciting the two front and rear wheels on either side of the vehicle with the vibration means, so the vehicle can be more accurately By optimizing the balance, steering stability and ride comfort can be improved.

Further, as another configuration of the vehicle height adjusting device that solves the above-described problem, the vehicle height adjusting means that is provided on at least one wheel of the vehicle and adjusts the vehicle height of the vehicle, and is provided on all the wheels of the vehicle, the traveling Wheel load measuring means for measuring wheel load values that change due to vibration applied to the wheels of the vehicle in the vehicle, and the pitch roll transmission of the vehicle based on the vibration excitation frequency and the measured wheel load value of each wheel of the vehicle Controls the vehicle height adjustment means so that the phase value in the pitch roll transfer characteristic approaches zero when the frequency is 1 Hz higher than the gain peak frequency in the pitch roll transfer characteristic. Vehicle height control means.
According to this configuration, in addition to the above effects, the vehicle is adjusted so that the balance of the vehicle is optimal during traveling of the vehicle, so that stable steering stability performance and good riding comfort can always be maintained.

It is a conceptual diagram which shows one Embodiment of a vehicle height adjustment apparatus. It is a top view of a vehicle height adjusting device. It is a figure which shows the gain and phase value which were output as a response by vibration. It is a flowchart of the vehicle height adjustment by a control unit. It is a conceptual diagram which shows other embodiment of a vehicle height adjustment apparatus. It is a conceptual diagram which shows other embodiment of a vehicle height adjustment apparatus.

  Hereinafter, the present invention will be described in detail through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are solutions of the invention. It is not necessarily essential to the means, but includes a configuration that is selectively adopted.

Embodiment 1
FIG. 1 is a conceptual diagram showing an embodiment of a vehicle height adjusting device 1 according to the present invention. FIG. 2 is a plan view of the vehicle height adjusting device 1. Hereinafter, the vehicle height adjusting device 1 will be described with reference to FIGS. 1 and 2. In the subscript letters shown below, f indicates the front wheel side and r indicates the rear wheel side. Further, fr indicates the right front wheel, fl indicates the left front wheel, rr indicates the right rear wheel, and rl indicates the left rear wheel. In addition, frrl indicates a combination of diagonal wheels including a right front wheel and a left rear wheel, and fl-rr indicates a combination of diagonal wheels including a left front wheel and a right rear wheel.
The vehicle height adjusting device 1 includes a vehicle height adjusting means 4 that makes it possible to adjust the vehicle height, a wheel load measuring means 6 that measures the wheel load values W _fr , W _fl , W _rr , W _rl of the vehicle, and wheels. Based on the wheel load values W _fr , W _fl , W _rr , W _rl of each wheel 8 measured by the wheel load measuring means 6 by the vibration of the vibration means 5. And a control unit 7 for controlling the vehicle height adjusting means 4.

The vehicle height adjusting means 4 according to the present invention is, for example, an air suspension provided in a vehicle.
The air suspension is composed of an air spring 11, a damper 12, and an air amount adjusting means 13 for adjusting the air amount of the air spring 11, and the vehicle height can be adjusted. The air spring 11 and the damper 12 are provided in pairs for each wheel 8.
The air spring 11 includes an airtight chamber and plays a role as a spring that supports the vehicle body by the pressure of air filled in the airtight chamber. The air spring 11 is connected to the air amount adjusting means 13 to adjust the air amount in the airtight chamber. The air spring 11 includes a pressure sensor 14 that measures the internal pressure in the air spring 11.
The pressure sensor 14 is connected to the control unit 7 and outputs the measured internal pressure in the air spring 11 to the control unit 7 as a signal. The damper 12 is, for example, a hydraulic attenuator and dampens vibration of the air spring 11.

The air amount adjusting means 13 includes, for example, a compressor 18 and a control valve 15. The compressor 18 is electrically connected to a control unit 7 described later, and is driven by a drive signal output from the control unit 7 to discharge pressurized air from a discharge port. A control valve 15 is individually provided for each air spring 11 at the discharge port.
The control valve 15 is electrically connected to the control unit 7, and supplies or stops the air discharged from the compressor 18 to the air spring 11 based on a signal output from the control unit 7, or stops the air in the air spring 11. Switch to exhaust air.

Specifically, the control valve 15 includes an intake port, a supply port, and an exhaust port. The control valve 15 communicates or blocks the suction port and the supply port, and a supply port provided on the downstream side of the open / close valve 16. And an exhaust valve 17 for communicating with or blocking the exhaust port. A pipe extending from the compressor 18 is connected to the suction port. A pipe extending from the air spring 11 is connected to the supply port. Further, the opening / closing valve 16 and the exhaust valve 17 are electrically connected to the control unit 7 individually, and are individually opened / closed based on a signal output from the control unit 7. Specifically, the on-off valve 16 opens the valve based on a signal output from the control unit 7, so that air from the compressor 18 can be supplied to the air spring 11. The exhaust valve 17 opens the valve based on a signal output from the control unit 7 and exhausts the air in the air spring 11. The on-off valve 16 and the exhaust valve 17 are set in a closed state at the initial state and when not controlled.
In the following description, the wheel 8 indicates the right front wheel as 8A, the left front wheel as 8C, the right rear wheel as 8D, and the left rear wheel as 8D. The air spring corresponding to the right front wheel 8A corresponds to 11A and the left front wheel 8C. The description will be made assuming that the air spring is 11C, the air spring corresponding to the right rear wheel 8D is 11B, and the air spring corresponding to the left rear wheel 8B is 11B.

The vibration means 5 includes a vibration machine 19 and a vibration control device 20 that controls the operation of the vibration machine 19. The vibration exciter 19 is provided to correspond to each wheel 8 and includes an actuator that vibrates the wheel 8 up and down, a load meter 22, and a wheel platform 23 on which the wheel 8 is placed.
The actuator includes a piston 21 that is connected to the vibration control device 20 and that moves forward and backward when the servo motor is driven by a signal output from the vibration control device 20. A wheel mount 23 is fixed to the upper surface of the piston 21.

The wheel mount 23 is composed of a rectangular flat plate whose upper surface and lower surface are formed in parallel, and measures wheel load values W _fr , W _fl , W _rr , W _rl of the wheel 8 when the wheel 8 is mounted. A load cell 22 is built in. A wheel mounting surface on which the wheel 8 is mounted is formed on the upper surface side of the wheel mounting base 23, and a wheel (not shown) that restricts the wheel 8 from moving in the front-rear direction and the left-right direction when the wheel 8 is mounted. A stop mechanism is provided. Moreover, it arrange | positions so that the measurement surface of the load cell 22 may become flush with a wheel mounting surface.
The load cell 22 is connected to the control unit 7 described later, and measures wheel load values W _fr , W _fl , W _rr , W _rl of the wheels and outputs them to the control unit 7.

The vibration control device 20 is a computer that controls the operation of the actuator of the vibrator 19, and includes a CPU as arithmetic processing means, ROM, RAM and HDD as storage means, and an interface as communication means. Operates based on stored programs. The vibration control device 20 is connected to input means such as a keyboard and a mouse (not shown) and display means such as a monitor.
The vibration control device 20 outputs the input amplitude and vibration frequency to the actuator of the vibration exciter 19 by the operator operating the input means and inputting the vibration amplitude and vibration frequency of the wheel 8. Thus, the vertical vibration of the wheel 8 by the actuator is controlled.
In the present embodiment, the vibration control device 20 controls the vibration exciter 19 so as to vibrate only one wheel of the vehicle, for example, the left front wheel 8C while changing the vibration frequency in the range of 0 to 6 Hz. Note that the range of the excitation frequency of 0 to 6 Hz assumes vibrations input to the wheels 8C from the road surface while the vehicle is traveling on a flat straight road.

The control unit 7 is a computer that executes processing for controlling the vehicle height adjustment means 4 so that the balance of the vehicle is optimal, and includes a CPU as arithmetic processing means, ROM, RAM and HDD as storage means, It includes an interface as communication means and operates based on a program stored in the storage means.
The control unit 7 includes input display means such as a touch panel, and commands and operation states for vehicle balance control are displayed on the input display means.
The vehicle balance is optimal when the center of gravity of the vehicle is positioned in the front-rear direction along the center of the vehicle body in the width direction, and in particular, the lines connecting the wheels 8A; 8B, 8C; Indicates that the vehicle is located at the center of the intersecting vehicle.

  As shown in FIG. 1, the control unit 7 includes a pitch roll calculating means 25 for calculating the pitch amount and roll amount of the vehicle vibrated by the shaker 19, the excited frequency, the roll amount, and the pitch amount. The pitch roll transfer characteristic setting means 26 for setting the pitch roll transfer function of the vehicle based on the above and the phase value of the pitch roll transfer function when the frequency is 1 Hz higher than the frequency at which the gain obtained by the pitch roll transfer function is zero. Vehicle height control means 27 for controlling the vehicle height adjustment means 4 is provided.

The pitch roll calculating means 25 calculates the pitch amount of the vehicle based on the wheel load values W _fr , W _fl , W _rr , W _rl output from the load meter 22 and the roll amount. A roll calculator 25B.
The pitch calculation unit 25A calculates the sum of the wheel load values W _fr and W _fl of the left and right front wheels 8A; 8C and the sum of the wheel load values W _rr and W _rl of the left and right rear wheels 8B; By calculating and subtracting the sum of the wheel load values W _rr , W _rl of the left and right rear wheels 8B; 8D from the sum of the wheel load values W _fr , W _fl of the left and right front wheels 8A; 8C, the wheel load values W _fr , W _fl , The vehicle pitch amount is calculated based on W _rr and W _rl . For example, if the sum of the wheel load values W _fr and W _fl of the left and right front wheels 8A; 8C is larger than the sum of the wheel load values W _rr and W _rl of the left and right rear wheels 8B; If the sum of the wheel load values W _fr , W _fl of the left and right front wheels 8A; 8C is smaller than the sum of the wheel load values W _rr , W _rl of the left and right rear wheels 8B; 8D, the posture of the vehicle is in a downward-sloping state. .
The roll calculation unit 25B calculates the sum of the wheel load values W _fr and W _rr of the right front and rear wheels 8A; 8D and the sum of the wheel load values W _fl and W _rl of the left front and rear wheels 8B; is calculated, the right front and rear wheels 8A; wheel load value W _fr of 8D, the front and rear left of the sum of W _rr wheel 8B; wheel load value W _fl of 8C, by subtracting the sum of the W _rl, wheel load value W _fr, The roll amount of the vehicle based on W _fl , W _rr , W _rl is calculated. For example, if the sum of the wheel load values W _fr , W _rr of the right front wheel 8A; 8D is larger than the sum of the wheel load values W _fl , W _rl of the left front wheel 8B; _Yes , if the sum of the wheel load values W _fr and W _rr of the right front and rear wheels 8A; 8D is smaller than the sum of the wheel load values W _fl and W _rl of the left front and rear wheels 8B; is there.

The pitch roll transmission characteristic setting means 26 is either a diagonal axis A1 or A2 of a diagonal axis A1 connecting the right front wheel 8A and the left rear wheel 8C or a diagonal axis A2 connecting the left front wheel 8B and the right rear wheel 8D. A pitch roll transfer function indicating a pitch roll transfer characteristic derived based on an equation of motion relating to a change in the center of gravity position of the vehicle is set. In other words, the vibration of the vibrator 19 is input, and the pitch roll transfer function is set based on the wheel load values W _fr , W _fl , W _rr , W _rl measured by the load meter 22 as a response to the input. The set pitch roll transfer function is stored in the storage means.

  In the present embodiment, paying attention to one diagonal axis A1 connecting the wheels 8A; 8B of the vehicle, the pitch roll transfer function based on the equation of motion at the center of gravity of the vehicle is stored in the control unit 7 to transmit the pitch roll. Set function parameters. The pitch roll transfer function is derived from an equation of motion based on the position of the center of gravity on the diagonal axis A1.

FIG. 3 is a diagram showing gain and phase values output as a response to excitation by the pitch roll transfer function. The vehicle height control means 27 includes a gain peak detection unit 31, a phase detection unit 32, and a vehicle height control unit 34.
As shown in FIG. 3, the gain peak detector 31 detects a gain peak from the gain that is output as a response by vibration, and outputs the peak frequency when the peak is detected to the phase detector 32. For example, the gain obtained with respect to the excitation frequency is scanned in the frequency direction to detect a peak, and the frequency at that time is output to the phase detection unit 32 as the peak frequency.
The phase detection unit 32 detects the value of the phase value when 1 Hz is added to the peak frequency of the gain output from the gain peak detection unit 31, and when the phase value is larger than the threshold value, the vehicle height with the phase value as a signal When the phase value is smaller than the threshold value, a control end signal is output to the vehicle height control unit 34.

The vehicle height control unit 34 controls the vehicle height based on the signal output from the phase detection unit 32. That is, control is performed when a phase value signal is output from the phase detector 32. Specifically, the vehicle height control unit 34 sets the internal pressure of the air spring 11 of the vehicle height adjusting means 4 so that the phase value output by the phase detection unit 32 becomes zero.
The vehicle height control unit 34 adjusts the vehicle height based on the following.
The vehicle height is repeatedly controlled so that the difference between the sum of the wheel load values W _fr and W _{rl on} the diagonal axis A1 of the vehicle and the sum of the wheel load values W _fl and W _{rr on} the diagonal axis A2 becomes zero. Thus, the phase value of the roll can be made zero. Note that the roll phase value can actually be made zero because the vehicle is in a stopped state and the wheel load value acting on the vehicle changes from moment to moment while the vehicle is running. Will be performed continuously.
In the present embodiment, the vehicle height adjustment is controlled only for the right rear wheel 8D, and the vehicle height adjustment value is set by adjusting the internal pressure of the air spring 11 so that the wheel load value _Wrr changes.

That is, the vehicle height control unit 34 determines that when the sum of the wheel load values W _fr and W _rl of one diagonal axis A1 is smaller than the sum of the wheel load values W _fl and W _rr of the other diagonal axis A2. The difference between the phase values of the diagonal axes A1 and A2 before the adjustment is zero, in other words, in the pitch roll transfer characteristic when the frequency is 1 Hz higher than the frequency at which the gain peak as the response of the pitch roll transfer function is obtained. The wheel load value W _rr is increased by lowering the internal pressure in the air spring 11 so that the phase value approaches zero, and the wheel load values W _fr , W _fl , W _rr , W _rl are measured again to measure the air spring 11. The wheel load value _Wrr is repeatedly adjusted until the difference between the phase values of the diagonal axes A1 and A2 becomes zero.
When the sum of the wheel load values W _fr ; W _rl of one diagonal axis A1 is larger than the sum of the wheel load values W _fl ; W _rr of the other diagonal axis A2, the diagonal at the time before the adjustment is adjusted. The difference between the phase values of the axes A1 and A2 is zero, in other words, the phase value in the pitch roll transfer characteristic when the frequency is 1 Hz higher than the frequency at which the gain peak as the response of the pitch roll transfer function is close to zero. By increasing the internal pressure in the air spring 11, the wheel load value W _rr is decreased, and the wheel load values W _fr , W _fl , W _rr , W _rl are measured again to adjust the internal pressure of the air spring 11. The wheel load value _Wrr is repeatedly adjusted until the difference between the phase values of the diagonal axes A1 and A2 becomes zero.

The vehicle height control unit 34 outputs a signal to the air amount adjusting means 13 so that the internal pressure of the air spring 11D of the right rear wheel 8D becomes a set pressure, and controls the air amount adjusting means 13 to Adjust the vehicle height on the right rear wheel 8D side so that the difference between the sum of the wheel load value W _fr ; W _rl of the angular axis A1 and the sum of the wheel load value W _fl ; W _rr of the diagonal axis A2 becomes zero To do.
Therefore, the control unit 7, the measured wheel load value W _fr at each wheel 8, W _fl, W _rr, wheel load value of the diagonal of _{W rl W fr; W rl,} W fl; difference of the sum of W _rr By controlling the vehicle height adjusting means 4 so as to be zero, the balance of the vehicle can be adjusted without depending on the damping force C of the damper 12 mounted on the vehicle or the spring coefficient K of the air spring 11. .

FIG. 4 is a flowchart of vehicle height adjustment by the control unit 7. Hereinafter, the operation of adjusting the vehicle height by the control unit 7 will be described.
First, the vehicle is placed on the shaker 19, and the shaker 19 is operated in a state where the driver gets on, and the left front wheel 8C of the vehicle is vibrated in the vertical direction while changing in the frequency range of 0 to 6 Hz. The wheel load values W _fr , W _fl , W _rr , W _rl of all the wheels are measured by the load meter 22 (S101).
Based on the wheel load values W _fr , W _fl , W _rr , W _rl , the vehicle pitch amount and roll amount are calculated by the load meter 22 corresponding to the excitation frequency (S102).

Next, the pitch roll transfer function setting means 26 is set by the pitch roll transfer characteristic setting means 26 with the excitation in the frequency range of 0 to 6 Hz as an input and the pitch amount and the roll amount as an output (S103).
Next, the gain peak detector 31 detects the peak by scanning the gain of the pitch roll transfer function in the frequency direction, detects the peak frequency when the peak is detected, and the phase detector 32 detects the peak frequency of the gain. The phase value when 1 Hz is added is detected (S104).
Next, when the phase value is equal to or smaller than the threshold value, the control is terminated, and when the phase value is equal to or larger than the threshold value, the process proceeds to S105 (S105).
Next, the phase value is zero when the frequency is 1 Hz higher than the frequency at which the gain peaks as a response to the pitch roll transfer function in which the difference between the phase values of the diagonal axes A1 and A2 is zero before the adjustment. An adjustment value for adjusting the internal pressure of the air spring 11D corresponding to the wheel 8D is set so as to approach (S106).
Next, the vehicle height control unit 34 supplies or discharges a predetermined amount of air to the air spring 11D of the right rear wheel 8D based on an adjustment value for adjusting the internal pressure of the air spring 11D corresponding to the wheel 8D. A signal is output to the adjusting means 13, and the air amount adjusting means 13 adjusts the internal pressure of the air spring 11D (S107).
Next, returning to S101, the wheel load values W _fr , W _fl , W _rr , W _rl are measured again, and the processing from S102 to S105 is performed, and 1 Hz from the frequency at which the gain peaks as the response of the pitch roll transfer function. The control is terminated when the phase value when the frequency is high falls below the threshold value.

As described above, the level control system 1 of the present invention, the wheel load value W _fr of wheels located diagonally in a _{vehicle; W rl, W fl; W} rr of the right rear wheel 8D based on the change of the sum Since only one wheel is subject to adjustment of the vehicle height, the vehicle height is adjusted so that the difference in the sum of the wheel load values W _fr, W _rl , W _fl, W _{rr on} the diagonal of the vehicle is zero. When controlling, it can control easily and the time concerning control can be shortened. Therefore, the diagonal wheel load values W _fr ; W _rl , W _fl ; W _rr so that the phase value when the frequency is 1 Hz higher than the frequency at which the gain peak as the response of the pitch roll transfer function is close to zero. A vehicle whose vehicle height is controlled so that the difference in the sum of the two becomes zero is excellent in dynamic balance such as steering stability performance and riding comfort.

Embodiment 2
In the first embodiment, any one wheel of the vehicle is vibrated up and down by the shaker 19 while changing the frequency in the range of 0 to 6 Hz. In the second embodiment, either one side of the vehicle is vibrated. The difference is that the front and rear wheels 8A; 8D, 8B; 8C are vibrated.

  The vibration means 5 of the present embodiment has the operations of the vibrators 19; 19 and the vibrators 19; 19 provided corresponding to, for example, the right and left front wheels 8A; 8D of the vehicle shown in FIGS. It is comprised with the vibration control apparatus 20 to control. The vibration control device 20 performs control so that each of the vibrators 19 and 19 vibrates while changing in the range of the vibration frequency of 0 to 6 Hz with the same phase up and down.

When the right front and rear wheels 8A; 8D are vibrated in the same phase by the vibrators 19; 19, as in the present embodiment, the input to the vehicle can be increased, and the change in the center of gravity position in the vehicle can be increased. Thus, based on the wheel load values W _fr , W _fl , W _rr , W _rl measured by exciting with a large input, 1 Hz from the frequency at which the gain peak as a response of the pitch roll transfer function is obtained. A vehicle in which the vehicle height is adjusted by repeatedly adjusting the internal pressure of the air spring 11D corresponding to the right rear wheel 8D so that the phase value when the frequency is high approaches zero will cause a large input in actual traveling. In addition, compared with the balance of the vehicle adjusted according to the first embodiment, the stability is improved with respect to the change in the posture of the vehicle. Therefore, even if the vehicle travels on a road surface with large unevenness or a road with large undulations, it is excellent in dynamic balance such as steering stability performance and riding comfort.

  In the present embodiment, the right front and rear wheels 8A; 8D have been described as being vibrated in the same phase, but they may be in opposite phases. Moreover, although it demonstrated that the right front-rear wheel 8A; 8D was vibrated, you may make it vibrate the left front-rear wheel 8B; 8C.

Embodiment 3
FIG. 5 is a conceptual diagram showing another embodiment of the vehicle height adjusting device 1.
In the first embodiment and the second embodiment, the load meter 22 incorporated in the wheel mount 23 of the vibration exciter 19 that is the vibration means 5 has been described as the wheel load measurement means 6. The difference is that the pressure sensor 14 attached to the air spring 11 which is the height adjusting means 4 is used as the wheel load measuring means 6.

The wheel load measuring means 6 of the present embodiment is provided with a pressure sensor 14 attached to the air springs 11A; 11B; 11C; 11D corresponding to the wheels 8A; 8B; 8C; 8D and a signal output from the pressure sensor 14. The wheel load conversion means 28 measures the wheel load values W _fr , W _fl , W _rr , W _rl of each wheel 8A; 8B; 8C; 8D.
The wheel load conversion means 28 is incorporated in the control unit 7, for example, and is a pressure wheel load that calculates wheel load values W _fr , W _fl , W _rr , W _rl based on the internal pressure of the air spring 11 output from the pressure sensor 14. The pressure values of the air springs 11A; 11B; 11C; 11D that are provided with conversion data and are output from the pressure sensor 14 are converted into wheel load values W _fr , W _fl , W _rr , W _rl . The wheel load values W _fr , W _fl , W _rr , W _rl converted by the wheel load conversion means 28 are output to the pitch roll calculation means 25. Therefore, the pitch roll calculating unit 25 can calculate the pitch amount and the roll amount based on the wheel load values W _fr , W _fl , W _rr , W _rl converted by the wheel load converting unit 28, and the converted wheel load. Based on the values W _fr , W _fl , W _rr , W _rl , it corresponds to the wheel 8D so that the phase value becomes zero when the frequency is 1 Hz higher than the frequency at which the gain as a response of the pitch roll transfer function is peaked. The vehicle height can be adjusted by repeatedly adjusting the internal pressure of the air spring 11D. Even if the vehicle height adjusting device 1 is configured in this manner, the same effects as those of the first and second embodiments can be obtained.

Embodiment 4
FIG. 6 is a conceptual diagram showing another embodiment of the vehicle height adjusting device 1.
In the first to third embodiments, it has been described that the vehicle height is adjusted by exciting the vehicle by the vibration exciter 19 of the vibration means 5. 8A; 8B; 8C; different in that the vehicle height is adjusted based on vibrations input to 8D.

The vehicle height adjusting apparatus 1 according to the present embodiment includes a vibration detection unit 29 that detects vibrations input to the wheels 8A; 8B; 8C; 8D from the road surface in addition to the configuration that does not include the vibration unit 5 in the third embodiment. And vibration converting means 30 for converting the vibration detected by the vibration detecting means 29 into an amplitude and a frequency.
The vibration detecting means 29 is individually connected to the pressure sensors 14 of the air springs 11A; 11B; 11C; 11D, and corresponds to the air springs 11A; 11B; 11C; 11D based on a signal output from the pressure sensor 14. Changes in internal pressure of the wheels 8A; 8B; 8C; 8D are detected.
The vibration converting unit 30 converts the vibration detected by the vibration detecting unit 29 as an input to the pitch roll transfer function into an amplitude and a frequency and outputs the amplitude and frequency to the pitch roll transfer characteristic setting unit 26.

  In this embodiment, the vibrations input from the wheels 8A; 8B; 8C; 8D of the running vehicle are input to the pitch roll transfer function, and the frequency is 1 Hz from the frequency at which the gain peak as the response of the pitch roll transfer function is obtained. The vehicle balance is optimized by adjusting the vehicle height by repeatedly adjusting the internal pressure of the air spring 11D corresponding to the right rear wheel 8D so that the phase value in the pitch roll transfer function when the engine is high approaches zero. It will be excellent in dynamic balance such as steering stability performance and ride comfort.

  In the present embodiment, the vehicle is provided with steering detecting means such as a steering sensor for detecting steering at the front wheels 8A; 8C, the steering sensor and the control unit 7 are electrically connected, and the steering sensor is used to determine whether or not steering is performed. By detecting the above and controlling the vehicle height only when the vehicle is traveling straight, it is possible to prevent the steering stability from being impaired while the vehicle is turning.

In Embodiment 1 to Embodiment 4 described above, the vehicle height is adjusted by repeatedly adjusting the internal pressure of the air spring 11D corresponding to the right rear wheel 8D. However, the control unit 7 controls the left and right rear wheels 8B; The internal pressures of the air springs 11B and 11D corresponding to the above may be adjusted. Pitch roll when the control unit 7 adjusts the internal pressure of the air springs 11B; 11D corresponding to the two wheels of the left and right rear wheels 8B; 8D, and the frequency is 1 Hz higher than the frequency at which the gain peaks as the response of the pitch roll transfer function. By adjusting the vehicle height corresponding to the left and right rear wheels 8B; 8D so as to control the vehicle height so that the phase value in the transfer function approaches zero, the wheel load values W _fr of the different diagonal axes A1; A2; Since the sum of W _rl , W _fl ; W _rr can be individually controlled, it is possible to control the vehicle height with high accuracy, so that the dynamic balance of steering stability and ride comfort is even better. Can be.

Further, the vehicle height may be adjusted by adjusting the internal pressure of the air springs 11A; 11D, 11B; 11C corresponding to the front and rear wheels 8A; 8D, 8B; 8C on either one side. The air springs 11A; 11D, 11B; 11C corresponding to either one of the front and rear wheels 8A; 8D, 8B; 8C on one side are adjusted to adjust the internal pressure of the air springs 11A, 11D, 11B; Adjustment of the vehicle height by adjusting the vehicle height corresponding to the front and rear wheels 8A; 8D, 8B; 8C so as to control the vehicle height so that the phase value in the pitch roll transmission characteristic when the frequency is high approaches zero. The range and adjustment accuracy can be further improved.
Since the vehicle height is controlled based on the changes in the wheel load values W _fr , W _fl , W _rr , W _rl of the wheels positioned diagonally, the wheels 8A; 8B, 8C positioned diagonally different from each other. Since each wheel of 8D is controlled, the vehicle load with high accuracy can be obtained by individually controlling the sum of the wheel load values W _fr, W _rl , W _fl ; W _rr of different diagonal axes A1; A2. It is possible to control the dynamic balance of the steering stability performance and the ride comfort.

  Moreover, you may make it adjust the internal pressure of air spring 11A; 11B; 11C; 11D corresponding to all the wheels 8A; 8B; 8C; 8D by the control unit 7. FIG. When the internal pressure of the air springs 11A; 11B; 11C; 11D corresponding to all the wheels 8A; 8B; 8C; By adjusting the vehicle height corresponding to the wheels 8A; 8B; 8C; 8D so that the phase value in the pitch roll transmission characteristic approaches zero, the vehicle weight increases due to the ride of a person and the loading of luggage. Even if the overall vehicle height decreases, the minimum ground clearance required can be secured by adjusting the vehicle height of all wheels 8A; 8B; 8C; 8D, and the balance of the vehicle is optimally controlled. be able to.

In the first to fourth embodiments, it has been described that the vehicle includes the air suspension as the vehicle height adjusting means 4. However, the vehicle is not limited to the air suspension, and the hydraulic vehicle height adjusting means 4 or mechanical It is only necessary to provide a vehicle height adjusting device such as a vehicle height adjusting means 4 for adjusting the vehicle height. In this case, the vehicle height may be controlled by appropriately changing the type of signal output from the control unit 7 according to the type of the vehicle height adjusting means 4.
Further, the vehicle height adjusting means 4 need not be provided so as to correspond to all the wheels 8A; 8B; 8C; 8D of the vehicle, and may be provided on at least one of the wheels. Preferably, the vehicle height adjusting means 4 is provided to correspond to the left and right front wheels 8A; 8C, or to correspond to the left and right rear wheels 8B; 8D, or to either one of the front and rear wheels 8A; 8D, 8B; 8C. As a result, the left and right vehicle heights of the diagonal axes A1; A2 can be adjusted, so that the balance of the vehicle can be adjusted with higher accuracy, and steering stability and ride comfort can be improved.

  As described above, if the vehicle height is adjusted by the vehicle height adjusting method and apparatus according to the present invention, the balance of the vehicle is always maintained even when the vehicle is stationary or running, so that the steering stability and ride comfort are optimal. Can be.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the above embodiment.

1 vehicle height adjusting device, 4 vehicle height adjusting means, 5 excitation means, 6 wheel load measuring means,
7 control units, 8 wheels,
8A Right front wheel, 8B Left rear wheel, 8C Left front wheel, 8D Right rear wheel,
11; 11A; 11B; 11C; 11D Air spring, 12 damper,
13 Air amount adjusting means, 14 Pressure sensor, 19 Exciter,
20 vibration control device, 22 load cell, 25 pitch roll calculation means,
25A pitch calculation unit, 25B roll calculation unit, 26 pitch roll transfer characteristic setting means,
27 vehicle height control means, 31 gain peak detector, 32 phase detector,
34 Vehicle height control unit, A1; A2 diagonal axis, W _fr ; W _fl ; W _rr ; W _rl wheel load value.

Claims (6)

At least one vehicle is provided with vehicle height adjustment means that can adjust the vehicle height, and any one wheel of the vehicle is vibrated in the vertical direction while changing the frequency in the frequency range of 0 to 6 Hz by the vibration means. And measure the change in the wheel load value of all the wheels,
Based on the vibration frequency and the measured wheel load value of each wheel, set the pitch roll transmission characteristics of the vehicle,
A vehicle height adjustment method for controlling the vehicle height adjustment means such that a phase value in the pitch roll transmission characteristic when the frequency is 1 Hz higher than a frequency at which the gain is peak in the pitch roll transmission characteristic approaches zero. Up and down direction while changing the frequency in the frequency range of 0 to 6 Hz with one of the two front and rear wheels on one side of the vehicle provided with vehicle height adjustment means that enables vehicle height adjustment to at least one wheel To change the wheel load value of all the wheels of the vehicle,
Based on the vibration frequency and the measured wheel load value of each wheel, set the pitch roll transmission characteristics of the vehicle,
A vehicle height adjustment method for controlling the vehicle height adjustment means such that a phase value in the pitch roll transmission characteristic when the frequency is 1 Hz higher than a frequency at which the gain is peak in the pitch roll transmission characteristic approaches zero. Measuring a change in wheel load value due to vibration applied to all the wheels while the vehicle is provided with vehicle height adjusting means capable of adjusting the vehicle height on at least one wheel;
Based on the vibration frequency and the measured wheel load value of each wheel, the pitch roll transmission characteristic of the vehicle is set,
A vehicle height adjustment method for controlling the vehicle height adjustment means such that a phase value in the pitch roll transmission characteristic when the frequency is 1 Hz higher than a frequency at which the gain is peak in the pitch roll transmission characteristic approaches zero. Vehicle height adjusting means provided on at least one wheel of the vehicle for adjusting the vehicle height of the vehicle;
Wheel load measuring means provided on all the wheels of the vehicle for measuring the wheel load value of the vehicle;
Vibration means for vibrating one wheel of the vehicle up and down while changing the frequency in a frequency range of 0 to 6 Hz;
Pitch roll transmission characteristic setting means for setting the pitch roll transmission characteristic of the vehicle based on the vibration frequency and the measured wheel load value of each wheel of the vehicle;
Vehicle height control means for controlling the vehicle height adjustment means so that the phase value in the pitch roll transmission characteristic when the frequency is 1 Hz higher than the frequency at which the gain rolls in the pitch roll transmission characteristic is higher than zero. High adjustment device. Vehicle height adjusting means provided on at least one wheel of the vehicle for adjusting the vehicle height of the vehicle;
Wheel load measuring means provided on all the wheels of the vehicle for measuring the wheel load value of the vehicle;
Vibration means for vibrating the two wheels on one side of the vehicle up and down while changing the frequency in a frequency range of 0 to 6 Hz;
Pitch roll transmission characteristic setting means for setting the pitch roll transmission characteristic of the vehicle based on the vibration frequency and the measured wheel load value of each wheel of the vehicle;
Vehicle height control means for controlling the vehicle height adjustment means so that the phase value in the pitch roll transmission characteristic when the frequency is 1 Hz higher than the frequency at which the gain rolls in the pitch roll transmission characteristic is higher than zero. High adjustment device. Vehicle height adjusting means provided on at least one wheel of the vehicle for adjusting the vehicle height of the vehicle;
Wheel load measuring means that is provided on all the wheels of the vehicle and measures wheel load values that change due to vibration applied to the wheels of the traveling vehicle;
Pitch roll transmission characteristic setting means for setting the pitch roll transmission characteristic of the vehicle based on the vibration frequency of the vibration and the measured wheel load value of each wheel of the vehicle;
Vehicle height control means for controlling the vehicle height adjustment means so that the phase value in the pitch roll transmission characteristic when the frequency is 1 Hz higher than the frequency at which the gain rolls in the pitch roll transmission characteristic is higher than zero. High adjustment device.

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