JPH0825377B2 - Vehicle stabilizer control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle stabilizer control device in which unsprung members of left and right wheels are connected by a stabilizer.

[Conventional technology]

2. Description of the Related Art Conventionally, for example, in Japanese Patent Laid-Open No. 61-146612, there is known a stabilizer that uses a hydraulic cylinder that expands and contracts by hydraulic pressure to control the attitude of a vehicle. This is to calculate the control amount of the hydraulic cylinder in order to suppress the lateral tilt (roll) of the vehicle body that occurs when the vehicle turns.
This is a vehicle stabilizer control device in which the hydraulic cylinder is controlled to expand and contract based on this control amount.

Further, in such a device, when the turning lateral acceleration is zero or can be regarded as zero, such as during straight traveling or during low-speed minute steering, the upper and lower chambers of the hydraulic cylinder are connected to each other and the stabilizer-specific twisting is performed. Riding comfort can be improved by controlling so that the vehicle does not exhibit high rigidity.

[Problems to be Solved by the Invention]

It is known that in the above-mentioned device, it is preferable to perform the control based on the magnitude of the lateral turning acceleration. For this purpose, methods such as using a lateral acceleration sensor and estimating and calculating a turning lateral acceleration from data of vehicle speed and steering angle are adopted. Then, when the lateral acceleration becomes zero or becomes lower than a certain threshold value, communication control is performed in which the hydraulic cylinder that emphasizes riding comfort can be expanded and contracted.

However, if such lateral acceleration sensitive control is performed, the lateral acceleration is determined to be zero even when the vehicle is stopped, and the hydraulic cylinder is controlled to be extendable and contractible. In this case, when the occupant gets on and off, the stabilizer does not act, and the sway of the vehicle body increases, which gives the occupant an uncomfortable feeling.

In addition, a solenoid valve is used to control the hydraulic cylinder,
The structure is designed so that the hydraulic cylinder is kept in an oil-tight state in order to ensure safety in the event of a failure such as disconnection of the solenoid valve coil. Therefore, in order to control the hydraulic cylinder to be in the communicating state, it is necessary to keep energizing the solenoid valve coil for making the communication-disconnection, which is not preferable in terms of power consumption when the vehicle is stopped, where the amount of power generation is reduced.

The present invention is to eliminate such inconveniences in the vehicle stabilizer control device.

[Means for solving the problem]

Therefore, as shown in FIG. 8, the present invention relates to a vehicle stabilizer that suppresses a roll generated in a vehicle body due to torsional rigidity and a vehicle stabilizer and the vehicle body in order to vary the torsional rigidity of the vehicle stabilizer. An expandable cylinder device provided between the cylinder device and the flow of the oil liquid in the cylinder of the cylinder device in order to limit the adjustment of the expansion and contraction amount of the cylinder device by keeping the cylinder device in the normally disconnected state when power is not supplied. And a non-turning state determination means for determining that the vehicle is in a non-turning state, and a control valve that is controlled to be in a communication state in response to power supply by energization and allows the flow of the internal oil liquid in the cylinder. And an occupant entry / exit state in which the entry / exit state in which the occupant can enter / exit the vehicle is detected by determining whether the vehicle is stopped or not. Output means, the control valve, when the non-turning state determination means determines the non-turning state of the vehicle, the control valve is energized to set the cylinder device to extend and retract, When the vehicle stabilizer and the vehicle body are not connected to each other and the occupant getting on / off state detecting means detects the occupant getting on / off state, the control valve is de-energized, and the cylinder device is connected. And a shut-off means for fixing the vehicle in a non-expandable manner, and controlling the posture of the vehicle by controlling the expansion and contraction of the cylinder device according to the turning state of the vehicle.

[Action]

According to the above configuration of the present invention, in order to suppress the roll generated in the vehicle in the turning state, the expansion and contraction control of the cylinder device is performed so as to twist the stabilizer. In this expansion / contraction control, the flow of the oil liquid in the cylinder of the cylinder device is prohibited when it is not energized to prohibit the flow of the oil liquid in the cylinder device. A control valve that allows the Further, when it is determined that the vehicle is in a non-turning state, that is, when the vehicle is traveling straight ahead, the stabilizer and the vehicle body can be uncoupled by setting the cylinder device to extend and retract so that the stabilizer action can be eliminated. it can. As a result, steering stability can be improved without deteriorating the riding comfort during straight running.

Further, the entry / exitable state in which the occupant can get on and off the vehicle is detected by determining whether the vehicle is stopped or not stopped. Then, when the entry / exit state is detected, the control valve stops the energization to control the cylinder device so that it cannot be expanded or contracted. As a result, the stabilizer and the vehicle body are connected to each other and the torsional rigidity unique to the stabilizer is established. To occur. Therefore, while suppressing the amount of power consumption when the vehicle is stopped in which the amount of power generation is reduced, the torsional rigidity of the stabilizer can reduce the shaking of the vehicle body when getting on and off the vehicle, thereby eliminating discomfort to the occupant.

〔The invention's effect〕

As described above, the present invention suppresses the roll that occurs in the vehicle in a turning state to appropriately control the vehicle city administration, and eliminates the action of the stabilizer during non-turning, that is, while traveling straight, to prevent a bad road or the like. It is possible to provide a high riding comfort in which the change in vehicle posture due to the unevenness of the road surface is reduced. In addition, by stopping the power supply to the cylinder device when the vehicle in which the amount of power generation is stopped is stopped, the power consumption is suppressed, and when the occupant or luggage gets in or out of the vehicle, the vehicle shakes due to the change in load balance. Is reduced by the action of the stabilizer.
Therefore, the passenger's discomfort can be eliminated.

EXAMPLES Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows the entire configuration of a stabilizer control device for an automobile to which the present invention is applied. Here, an embodiment applied to a front wheel side stabilizer of a vehicle is shown.

As shown in the figure, the present vehicle stabilizer control device 1 is composed of a front wheel stabilizer device 2, a hydraulic device 3, and an electronic control device 4 for controlling them.

In the front wheel stabilizer device 2, the left front wheel 6 is supported by the vehicle body 9 by the left front wheel shock absorber 7 and the left front wheel suspension arm 8. Also, the right front wheel 10
Is supported on the vehicle body 9 by a right front wheel shock absorber 11 and a right front wheel suspension arm 12. further,
The torsion portion of the front wheel stabilizer bar 13 is rotatably supported on the vehicle body 9 by bearings 14 and 15 fixed to the vehicle body 9 with bolts or the like. One end portion 13a of the front wheel side stabilizer bar 13 is coupled to the unsprung portion of the right front wheel shock absorber 11 via a cylinder unit 16 whose connection distance can be adjusted (expandable / contractible). The connection distance between the one end portion 13a of the front wheel side stabilizer bar 13 and the unsprung portion of the right front wheel shock absorber 11 depends on the control signal of the electronic control unit 4.
It can be adjusted by expanding and contracting the cylinder unit 16 on the front wheel side, which receives the supply of pressure oil from the hydraulic circuit 3. The other end 13b of the front wheel side stabilizer bar 13 is attached to the unsprung portion of the left front wheel shock absorber 7 via a link rod 17. Further, in order to steer the vehicle, a steering mechanism 19 that changes the directions of the left and right front wheels 6 and 10 in accordance with the operation of the steering wheel 18 is also provided.

The vehicle stabilizer control device 1 is a detector that uses a vehicle speed sensor 41 for detecting the traveling speed of the vehicle, a steering angle sensor 42 for detecting the steering angle, and a cylinder unit 16 extending from its neutral position (midpoint of piston stroke). Stretching switch 43 to detect whether it is on the side or on the contracted side
Is provided. The signals from these detectors are sent to the electronic control unit 4
The electronic control device 4 controls the hydraulic device 3 to control the front wheel stabilizer device 2.

In the cylinder unit 16, the piston rod 27 is attached to the unsprung part of the right front wheel shock absorber 11, and the cylinder 21
Is coupled to one end portion 13a of the front wheel side stabilizer bar 13. Therefore, the front wheel side stabilizer device 2 changes the twist amount of the front wheel side stabilizer bar 13 by the movement of the piston 22 of the cylinder unit 16 over a predetermined stroke amount and increases the apparent reaction force by increasing the twist reaction force. It is configured to change the torsional rigidity.

As shown in FIG. 2, the cylinder unit 16 is expanded and contracted by pressure oil supplied from the hydraulic device 3 in response to a control signal from the electronic control device 4.

In the hydraulic device 3, a hydraulic pump 31 driven by an engine 30 via a power transmission mechanism sucks hydraulic oil from a reservoir tank 34, and a pipe 33a, a control valve (4 port 3-position solenoid valve) 32, a pipe Pressure oil is supplied to the cylinder unit 16 via 33c and 33d. The flow paths 33c and 33d are connected to the flow control valve (2
Port 2 position solenoid valve) 35. Flow control valve
35 is further connected to the reserve tank 34 through a line 33e. The control valve 32 responds to a control signal from the electronic control unit 4 to select a neutral position 32a, an extension position 32b, and a contraction position 32c.
The position and any intermediate position between them can be switched.
Further, the flow control valve 35 has a shutoff position 35a and a communication position 35b.
The position and any intermediate position between them can be switched.

Here, the configuration of the control valve 32 will be described. Control valve 32
Can be realized by, for example, a spool valve structure having two linear solenoids. When only one of the two linear solenoids is energized, the neutral position 32a is extended to the extended position 3a.
It moves to the 2b side and moves to the contracted position 32c side when only the other side is energized, and the moving amount of the spool can be changed by the energizing current. With this configuration, the expansion and contraction of the cylinder unit 16 can be selected by selecting the solenoid to be energized, and the opening area of the port connected to the outflow side conduit of the cylinder unit 16 can be changed depending on the magnitude of the energized current. The amount of oil flowing out from the cylinder unit 16 can be adjusted. That is, the control valve 32 realizes the function of the three-position directional control valve with the flow control function of the meter-out hydraulic circuit by one valve.

Further, the flow control valve 35 can be realized by, for example, a structure of a spool valve, and the movement amount of the spool can be continuously changed from the fully closed position 35a to the fully opened position 35b by the magnitude of the current supplied to the linear solenoid. . In the fully closed state, the upper and lower chambers 25 and 26 of the cylinder unit 16 are shut off, and as the current supplied to the linear solenoid increases, the cylinder unit 16
Starting to communicate the upper and lower chambers 25, 26 and the reserve tank 34,
At maximum current, full communication is established. That is, the communication opening area increases in proportion to the current value.

Further, these solenoid valves are designed so that when the energizing current is zero, the control valve 32 returns to the neutral position 32a and the flow control valve 35 returns to the shutoff position 35a.

As shown in FIG. 2, the electronic control unit 4 is composed of a microcomputer and the like, and can receive various sensor signals by an appropriate input / output circuit and drive the solenoid valve.

The input part of the electronic control unit 4 includes a vehicle speed sensor 41 for detecting the vehicle speed, a steering angle sensor 42 for detecting the rotation angle (steering angle) of the steering wheel, and an expansion / contraction switch 43 for detecting the expansion / contraction state of the cylinder unit 16. A signal is input.

The expansion / contraction switch 43 can be realized by the following configuration, for example. The piston rod 27 of the cylinder unit 16 has a structure in which a magnetic material and a non-magnetic material such as iron and stainless steel are connected together in the middle, and a coil around which a conductive wire is wound so that the piston rod 27 becomes the inner core is formed on the upper portion of the cylinder 21. Install. When the inductance of the coil is measured with such a structure, the values obtained when the inner core is made of a magnetic material such as iron and the case where the inner core is made of a non-magnetic material such as stainless steel are greatly different.

Therefore, FIG. 3 shows a circuit for measuring the inductance. 4e-1 is a pulse generator that outputs a pulse waveform of a predetermined frequency to the coil 43A, which is the output unit 4 of the electronic control unit 4.
It is provided in e. The coil 43A is provided on the outer circumference of the piston rod 27 and outputs a transient response signal related to the inductance of the coil. In addition, in the input unit 4d of the electronic control unit 4,
Input comparison circuit 4d-1, pulse width-voltage conversion circuit 4d-2,
A threshold circuit 4d-3 is provided, and the input comparison circuit 4d-1
Generates a pulse that becomes 1 when the input signal is larger than the reference value Vref and becomes 0 when it is smaller, and the pulse width-voltage conversion circuit 4d-2 outputs an output voltage according to the signal width of the pulse signal, When the inductance of the coil is small (stainless steel), a “(low (L)” level signal is returned to the reference level V _{TH, which} is used to judge whether the inductance is large or small in the threshold circuit 4d-3. When the inductance is large, a "high (H)" level is output.

Although the configuration of FIG. 3 shows all processing examples by the electronic circuit, these may be replaced with software processing using a microcomputer as appropriate.

In the output section 4e of the electronic control unit 4, the solenoid valve 3
The part that outputs the current to 2,35 is the result of the calculation by the CPU 4a, even if the power supply voltage changes or the load impedance changes.
It has the function of stably supplying the required current. This structure can be realized by a circuit structure as shown in FIG. 4, for example. That is, the CPU 4a outputs a rectangular wave pulse having a maximum energizable current of 100% duty to the output unit 4e. This pulse is filtered by the filter circuit 4e-2 to turn the rectangular wave pulse ON-OF.
Converted to a voltage proportional to F duty ratio, differential amplifier 4e
Enter to -3. On the other hand, the current flowing through the linear solenoid of the control valve 32 is converted into a voltage by the current detection circuit 4e-6 composed of a resistor having a small resistance value, and is input to the differential amplifier 4e-3 through the filter circuit 4e-5. . The driver circuit 4e-4 composed of a power transistor or the like is controlled so that the difference between these two voltages becomes zero, and the control current supplied to the solenoid is adjusted. This circuit configuration may be prepared for the number of solenoids (three in this embodiment).

Next, a basic operation and control method will be described based on the above configuration.

First, straight traveling will be described. During straight running, the control valve 32 shown in FIG. 2 is set to the neutral position 32a. At this time, the pressure oil discharged from the hydraulic pump 31 is
Return to the reservoir 34 via a, the control valve 32, and the conduit 33b. on the other hand,
The flow rate control valve 35 is set to the communication position 35b. At this time, both the upper and lower chambers of the cylinder unit 16 are in communication with the reserve tank 34. Therefore, the cylinder unit 16
The piston 22 of can move freely in the cylinder 21 (expand and contract), and when the suspension arms 8 and 12 are displaced due to unevenness of the road surface, the force to twist the stabilizer 13 is The movement of the piston 22 is replaced via 27. That is, in the communication state 35b of the flow control valve 35, the cylinder unit 16 is set to be expandable and contractable, the stabilizer 13 and the unsprung member of the shock absorber are disconnected, and the inherent torsional rigidity of the stabilizer 13 is shocked. Since the suspension arm is not transmitted to the unsprung member and the free movement of the suspension arm is not limited as in a vehicle not equipped with a stabilizer, high riding comfort can be obtained.

Next, the time of turning will be described. At the time of turning, the target expansion / contraction amount of the cylinder unit 16 is determined according to a predetermined relationship depending on the vehicle speed and the magnitude of the steering angle. The hydraulic device 3 is driven so as to extend or contract the cylinder unit according to the value. That is, first, the flow control valve
35 is set to the cutoff mode 35a, and in the expansion mode,
Energize the linear solenoid that moves the control valve 32 to the extended position 32b side. At this time, in the control valve 32, the port connected to the conduit 33d connected to the lower chamber 26 of the cylinder unit 16 is immediately fully opened, and the pressure oil from the pump 31 is transferred to the conduit 33.
Lower chamber of cylinder unit 16 via a, control valve 32, and conduit 33d
Supply to 26. On the other hand, the port of the control valve 32 connected to the upper chamber 25 of the cylinder unit 16 operates so that the opening area thereof increases with the magnitude of the energizing current, so when the piston 22 tries to move upward, The amount of oil flowing out through the conduit 33c is adjusted. In other words, the piston 22 can move only after a certain amount of oil has flowed out of the upper chamber 25, so by changing the energizing current of the linear solenoid,
The amount of movement of the piston 22 can be adjusted. Moreover,
Since the relationship between the magnitude of the energizing current and the amount of spilled oil, that is, the amount of movement of the piston can be known in advance, the electronic control unit 4
Is the amount of energizing current output and the energizing time
22 positions will be predicted and calculated. Therefore, the energizing current is controlled so that the predicted position quickly reaches the target position. In addition, since the prediction calculation can know the actual movement of the piston 22 in advance, the hydraulic device 3 can be driven while compensating for the response delay. Then, when it is determined that the target position is reached, the energization of the linear solenoid is terminated. At this time, the control valve 32 returns to the state of the neutral position 32a, the upper and lower chambers 25 and 26 of the cylinder unit 16 are kept in an oil tight state, and the piston 22 is fixed at the target position. Since the meter-out hydraulic circuit is configured as described above, the minute oil amount to the large oil amount can be accurately adjusted, so that the cylinder unit 16 can be accurately controlled. By this extension, the cylinder unit 16 is set to the extension mode during a right turn to positively generate torsional rigidity to the stabilizer 13 in the vehicle, and the roll angle of the vehicle body is reduced.

In the contraction mode, the linear solenoid that drives the control valve 32 to the contracted position 32c is energized. At this time, the control valve
In 32, the port connected to the conduit 33c connected to the upper chamber of the cylinder unit 16 is immediately fully opened and the pump 3
The pressure oil from 1 is supplied to the upper chamber 25 of the cylinder unit 16 via the pipe 33a, the control valve 32, and the pipe 33c. On the other hand, the port of the control valve 32 connected to the lower chamber 26 of the cylinder unit 16 operates so that the opening area thereof increases with the magnitude of the energizing current, and when the piston 22 tries to move downward,
The amount of oil flowing out through the conduit 33d is adjusted. Therefore,
As in the extension mode, the piston position is predicted, and when it is determined that the piston 22 has reached the target position, energization is terminated and the piston 22 is fixed at the target position. By this contraction, the cylinder unit 16 is set to the contraction mode at the time of turning left, and the torsional rigidity of the stabilizer 13 is positively generated in the vehicle, and the roll angle of the vehicle body is reduced.

The above is the operation during traveling, but when the vehicle is stopped, the power supply to the control valve 32 and the flow rate control valve 35 is stopped. Then, the control valve 32 is in the neutral position 32a and the flow control valve 35 is in the shut-off position 35a.
Thus, the upper and lower chambers 25 and 26 of the cylinder unit 16 are shut off, and the piston 22 is fixed in an oiltight manner so that it cannot expand and contract. Therefore,
The cylinder unit 16 acts as a kind of rigid body similarly to the link rod 17, and the stabilizer 13 exhibits its own torsional rigidity. Therefore, the sway of the vehicle body due to the change of the load balance is reduced by the stabilizer action when getting on or off the personnel or the luggage. Moreover, since the solenoid valve is not energized, power consumption can be reduced.

The above is the mechanical operation of the stabilizer control device for an automobile.

Next, the piston of the cylinder unit 16 in this device
A method of controlling the solenoid valves 32 and 35 for controlling the position of 22 (hereinafter, simply referred to as a stroke) will be described with reference to the flowchart of FIG.

FIG. 5 is a flowchart showing the overall flow of control, and FIG. 6 is a routine for calculating the vehicle speed required for the control of FIG. The process of FIG. 5 is repeatedly executed in a cycle (for example, 8 msec) sufficiently faster than the response time of the hydraulic device 3. Therefore, control that compensates for the response delay of the hydraulic system is possible. The vehicle speed calculation of FIG. 6 is performed at an interrupt timing different from that of the control routine of FIG.

In the present embodiment, as the vehicle speed sensor 41, a general one that converts the rotation speed of the output shaft of the engine output transmission into the frequency of the voltage pulse is dealt with. Interrupt the processing of Figure 5,
The processing of FIG. 6 is performed. In this method, when the vehicle is truly stopped, no vehicle speed pulse is generated and the vehicle speed cannot be calculated. Therefore, in the processing routine of FIG. 5, the time from the previous pulse generation to the next pulse generation is measured, and when this time becomes longer than a certain threshold value T _M , it means that the vehicle is stopped. A compensation process for making a determination is performed. This processing may be executed in step 100 in the flowchart of FIG.

 Next, each step will be described.

First, in step 100, the vehicle speed v and the steering angle θ (including the steering direction) are read. The vehicle speed v is a value obtained by the processing of FIG. 6 described later or a value obtained by the compensation processing described above. Next, at step 110, the turning lateral acceleration G is obtained from these values by G = k ₁ · θ · v ⁿ (k ₁ · n is a constant determined by the specifications of the vehicle). The steering angle θ used here is the rotation angle θ of the steering wheel 18, which is a value obtained by subtracting the steering dead band angle obtained in advance from the rotation angle of the steering wheel 18.

Next, at step 120, it is determined whether or not the vehicle is turning, depending on whether or not the value of the lateral acceleration G is zero. If it is determined in this process that the vehicle is turning, the process proceeds to step 130 and the subsequent steps. If it is determined that the vehicle is not turning, that is, the vehicle is not turning (straightening or stopping), the process proceeds to step 160 and below.

If the vehicle is turning, the control current value output to the flow control valve 35 is first set to zero in step 130. This is because the flow control valve 35 is set to the shutoff mode to eliminate the bypass to the cylinder upper and lower chambers 25 and 26 and the reserve tank 34. Next, the routine proceeds to step 140 to determine the control target stroke S _T based on the value of the lateral acceleration G. This is obtained by, for example, S _T = S ₀ ± k ₂ · G. Here, S ₀ is a value indicating the neutral position of the cylinder unit 16, and k ₂ is a known constant. Also,
Regarding the symbols in the formula, when the cylinder unit 16 is mounted on the right side (driver's seat side) of the vehicle as shown in FIG. 1, it means + (plus) to mean the extension side of the cylinder when turning right. And take a- (minus) to mean that it is on the compression side of the cylinder when turning to the left.

Next, in step 150, the drive current to the control valve 32 is obtained. This current is controlled in order to secure the outflow flow rate from the cylinder unit 16 necessary to make the deviation between the target stroke S _T and the predicted stroke S _C obtained in the previous calculation cycle zero. This is a valve opening drive current to the expansion mode 32b or the contraction mode 32c of the valve 32. After this, the process proceeds to step 200 and thereafter.

Next, when the vehicle is not turning, the process proceeds from step 120 to step 160 and thereafter. First, in step 160, the control valve 32
Set the output current value to the output to zero. This is for setting the control valve 32 to the neutral mode 32a. Then step 1
Proceed to 70. Here, based on the stop flag described later,
It is determined whether or not the vehicle is stopped. This is a process for distinguishing whether the vehicle is traveling straight ahead or stopped when the turning lateral acceleration is zero (not turning). If it is determined in this determination that the vehicle is not stopped, that is, the vehicle is traveling straight ahead, the process proceeds to step 180, and if it is determined that the vehicle is stopped, the process proceeds to step 190.
To each.

First, in step 180 during straight traveling, the output current to the flow control valve 35 is obtained according to the map shown in FIG.
The horizontal axis of FIG. 7 represents the vehicle speed, and the vertical axis represents the output current value with the current value (or the maximum current value that can be conducted) being stably in the communication mode being 100%. As can be seen from FIG. 7, in the control of this device, the flow rate control valve 35 is set to the communication mode when the vehicle travels straight at a low speed to free the piston 22. As a result, the stabilizer effect is eliminated and the riding comfort is improved. Further, as the vehicle speed increases, the output current is reduced, the valve opening of the flow control valve 35 is reduced, and the cutoff mode is completely set at a certain vehicle speed v ₁ or higher. As a result, during high-speed straight traveling, a normal stabilizer action is generated to secure steering stability and steering responsiveness. In FIG. 7, v ₀ represents the lowest vehicle speed v ₀ that can be calculated, and it may be determined that the vehicle is effectively stopped at a vehicle speed lower than this (vehicle speed sensor output pulse width is T _M or more). At that time, it is determined that the vehicle is stopped, and the process proceeds to step 190 and subsequent steps described below.

Next, in the processing of step 190 when it is determined that the vehicle is stopped, the output current to the flow control valve 35 is set to zero. As a result, a stabilizer action is generated while the vehicle is stopped, and rolling of the vehicle body due to a change in load distribution when getting on or off a person or luggage is prevented. In addition, when the engine speed is low and the amount of power generation is small, the solenoid valve is de-energized, so that power consumption can be reduced (temperature rise of the solenoid valve coil portion can be suppressed), and battery rise can be prevented.

Through the above processing, the output current values to the control valve 32 and the flow rate control valve 35 were obtained in all operating states. Therefore, in step 200, the flow control valves 35 and 210 output the respective set current values to the control valve 32.

Finally, in step 220, the predicted stroke S _C is calculated. This calculation is performed on the value of the current supplied to the control valve 32, and the relationship between the value of the current supplied to the control valve 32 and the amount of movement of the piston 22 is measured in advance, and this relationship is set as a map. To do. In each calculation cycle, as a result of the current output in step 210, the piston movement amount during the time until the next calculation cycle is obtained based on this map, and it is integrated to obtain the predicted stroke S _C. Note that the predicted stroke value due to this integration process may deviate from the actual stroke value due to the accumulation of minute errors, but the stroke expansion / contraction switch 43 detects that the actual stroke passes through the neutral position of the cylinder. Since this is possible, the deviation of the predicted stroke S _{C from} the actual stroke is corrected using this. The predicted stroke S _C thus obtained is used in the calculation of the output current value to the control valve 32 (step 150) in the next calculation cycle. The value of the predicted stroke S _C does not change because only the flow rate control valve 35 is driven and the control valve 32 remains in the neutral position 32a during straight traveling or when the vehicle is stopped.

Next, the vehicle speed calculation routine of FIG. 6 will be described.
As described above, in this embodiment, a general vehicle speed sensor that converts the transmission rotation speed of the engine output into the frequency of the voltage pulse will be considered.

First, at step 300, the current vehicle speed sensor pulse generation time is read. Next, in step 310, the pulse width T _P is obtained from the difference between this value and the previous pulse generation time.

In step 320, when it is determined that this pulse width T _P is a predetermined threshold value T _M (pulse width corresponding to the minimum vehicle speed value v ₀ that may be regarded as a vehicle stop state for practical use), the process proceeds to step 330. Then, the stop flag indicating that the vehicle is stopped is set, the process proceeds to step 340, the vehicle speed v is set to zero or v ₀ (minimum vehicle speed value), and the process ends. On the other hand, if it is determined in step 320 that T _P ≤T _M , step 3
The program proceeds to 50 and resets the flag indicating that the vehicle is stopped. Then, the program proceeds to 360 to obtain the vehicle speed v by v = k _v / T _P (k _v is a constant determined by the sensor specifications), and ends.

In this embodiment, it goes without saying that the solenoid valves 32, 35 are not energized when the engine is stopped.

In the above embodiment, in order to detect the possible entry / exit state in which the occupant can get in and out of the vehicle, the vehicle stop sensor is determined from the pulse generation interval of the vehicle speed sensor 41, but if the door is simply opened while the engine is rotating, the brake is applied. When the pedal is depressed, even when the transmission is set to the parking position, the control valve 32 may be set to the neutral mode 32a and the flow control valve 35 may be set to the cutoff mode 35a (that is, both energization currents are set to zero). However, in this case, although it is useful for preventing the rolling of the vehicle body against the next expected getting off of the occupant, it is preferable from the viewpoint of power consumption because the flow control valve 35 is continuously energized when the signal is stopped. Absent. Therefore, this logic is preferably used in combination with the above embodiment.

Further, in the present embodiment, the solenoid valve for communicating the cylinder upper and lower chambers is the flow control valve 35, but in a vehicle that does not need to be continuously changed, it may be simply a 2-port 2-position open / close valve.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of the present invention, FIG. 2 is a configuration diagram showing a hydraulic pressure and an electric circuit of the embodiment, and FIGS. 3 and 4 are partial electric circuits of the embodiment. Partial circuit diagrams shown in FIGS. 5, 5 and 6 are flowcharts showing processes executed by the electronic control unit, FIG. 7 is a map showing control characteristics, and FIG. 8 is a configuration diagram showing a schematic configuration of the present invention. 1 …… Stabilizer control device, 3 …… hydraulic device, 4 …… electronic control device, 7,11 …… shock absorber, 16 …… cylinder unit, 41 …… vehicle speed sensor, 42 …… steering angle sensor, 43…
… Stroke extension switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Onuma 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Hidenori Ichimaru 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. ( 72) Inventor Hiroyuki Ikemoto 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References JP 62-191211 (JP, A) JP 61-184110 (JP, A)

Claims (1)

[Claims] 1. A vehicle stabilizer that suppresses a roll generated in a vehicle body by torsional rigidity, and an expandable and contractable element provided between the vehicle stabilizer and the vehicle body in order to vary the torsional rigidity of the vehicle stabilizer. In order to limit the adjustment of the expansion and contraction amount of the cylinder device and the cylinder device, the flow of the oil liquid in the cylinder of the cylinder device is prohibited during the non-energization when the power is not supplied, and the power due to the electricity is supplied. A control valve that is controlled to be in communication with the supply to allow the flow of the internal oil liquid in the cylinder, a non-turning state determination unit that determines that the vehicle is in a non-turning state, and an occupant of the vehicle. An occupant boarding / alighting state detecting means for detecting the boarding / alighting possible state by determining whether the vehicle is stopped or not stopped, and When the non-turning state determination means determines the non-turning state of the vehicle, the control valve sets the cylinder device to extend and contract by energizing the control valve, and the vehicle stabilizer and the vehicle body are connected to each other. When the passenger occupant entry / exit possible state detection means detects an occupant entry / exit possible state, the control valve is de-energized to shut off the cylinder device so that the cylinder device cannot expand / contract. And a means for controlling the attitude of the vehicle by controlling the expansion and contraction of the cylinder device according to the turning state of the vehicle.