JPH0764178B2 - Stabilizer control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applicable even when a vehicle roll amount cannot be accurately estimated from a vehicle speed, a steering angle and the like while the vehicle is running. The present invention relates to a stabilizer control device that effectively suppresses rolling of a vehicle due to overcontrol of the stabilizer twist amount.

[Prior Art] When a vehicle shifts to a turning traveling state, rolling occurs due to the action of centrifugal force. In this case, the camber angle changes as the roll angle increases, so that the canvas last increases and the maneuverability and stability deteriorate. Therefore, in order to maintain the turning traveling state, it is necessary to frequently perform the correction steering. Controls such rolling and maneuverability
In order to improve the stability, for example, it is possible to set the spring constant of the suspension high, but in this case,
Shocking vibrations, such as when driving on rough roads, are not absorbed and ride comfort is reduced. Therefore, a stabilizer is provided in the vehicle that acts only when the suspension positions of the left and right wheels are different to generate a restoring force, to control the rolling.

However, even when the vehicle is not rolling, for example, when one of the left and right wheels rides on a protrusion on the road surface, a difference occurs in the suspension position of the left and right wheels. Will act as. Therefore, the riding comfort is reduced as in the case where the spring constant of the suspension is set high. As a countermeasure against such a defect, for example, the following technique has been proposed. That is, (1) the stabilizer and the wheel-side member are connected by a cylinder unit having two cylinder chambers formed by a piston and a cylinder body, and both cylinder chambers are connected by a switching valve to a pressure fluid source. A "stabilizer device" that adjusts the fluid pressure inside the cylinder unit, expands and contracts the cylinder unit, positively utilizes the action of the stabilizer, and controls the posture of the vehicle to prevent rolling during turning of the vehicle (Japanese Patent Laid-Open No. 61-61). -64514).

(2) "Vehicle attitude control device" (special feature) in which a control amount corresponding to the roll amount of the vehicle is calculated based on the traveling speed and the steering angle of the vehicle, and the torsional elasticity characteristic of the stabilizer is changed according to the control amount. (Kaisho 61-146612).

[Problems to be Solved by the Invention] By the way, in the above-mentioned conventional technology, the pressure fluid from the pressure fluid source is supplied to the cylinder unit to control the vehicle posture so as to be stable. However, when performing such control, the pressure fluid is discontinuous in the cylinder unit,
Alternatively, if the power is supplied in stages, shocking vibration that gives an occupant a feeling of strangeness, noise accompanying the vibration, and the like are generated in the vehicle, resulting in deterioration of riding comfort. Therefore, the applicant of the present application is an improved technique for eliminating the discomfort felt by an occupant by continuously controlling the flow rate of the pressure fluid from the fluid pressure source to the cylinder unit by a flow rate control valve when actively controlling the stabilizer. Stabilizer control device "(Japanese Patent Application No. 62-
148610) was proposed.

By the way, in the above-mentioned improved technology, the target stroke amount of the cylinder unit, which is the control amount when the vehicle is turning, is calculated according to the map according to the vehicle speed detected by the vehicle speed sensor and the steering angle detected by the steering sensor. However, for example, when traveling on a wet slope or a snowy slope with a low road friction coefficient, the drive wheels are stuck in these bad roads and cannot transmit the drive torque sufficiently, and the drive wheels are rotating. Nevertheless, there are cases in which the vehicle may transition to a so-called stuck state, which makes it difficult to escape from a bad road.
In this way, when the vehicle shifts to the so-called stack state, the drive wheels run idle, so the vehicle speed detected by the vehicle speed sensor becomes a large value, but the actual vehicle speed is extremely low or almost zero, and Since the vehicle is almost stopped, the steering angle does not reflect the actual turning state of the vehicle. Therefore, in such a case, when the control amount of the stabilizer is determined according to the vehicle speed detected by the vehicle speed sensor and the steering angle detected by the steer sensor, the detection result of the vehicle speed sensor is much larger than the actual vehicle speed, and Since the steering angle detected by the steering sensor also becomes larger than the steering angle corresponding to the actual turning radius, the calculated control amount also becomes an excessive value larger than the optimum value. For this reason, the amount of twist of the stabilizer becomes too large, and the problem that the vehicle induces rolling due to the active control of the stabilizer has been found out, and the above-mentioned improved technique has not been sufficient yet.

This makes the occupant feel uncomfortable and also deteriorates the riding comfort.

Further, it has been considered that the transition of the vehicle to the so-called stuck state as described above is determined based on, for example, the rate of change in vehicle speed. However, if the vehicle running state is determined based on the rate of change of the vehicle speed in this way, for example, when the vehicle shifts to the sudden acceleration state and the drive wheels are idling (so-called acceleration slip state). In some cases, it may be difficult to accurately distinguish between the case where the drive wheels are idling after shifting to the so-called stack state as described above. in this way,
When the shift to the so-called acceleration slip state is made, the rate of change in the rotational speed of the drive wheels becomes large, so if the normal active control is stopped by misjudging that the shift state has changed to the so-called stack state, the amount of twist of the stabilizer will change to the running state. Inappropriate improper value and vehicle rolls despite having active controllable stabilizers.

Further, for example, there is also a technique of detecting the rotational peripheral speeds or the rotational angular velocities of the drive wheels and the idler wheels, and determining that the difference or the ratio exceeds a predetermined value, the state is determined to be a so-called stack state. it was thought. However, in order to realize the above technology, the rotational peripheral speeds of the drive wheel and the idle wheel,
Alternatively, it is necessary to dispose a dedicated detector for detecting the rotational angular velocity under the spring of the vehicle. However, as is well known, the frequency of unsprung vibration is about one digit higher than the frequency of unsprung vibration, and wiring from the unsprung detectors to the sprung controller is required. It was also thought that the reliability and durability of the device would deteriorate.

Further, in order to accurately detect the shift to the so-called stack state as described above, it has been considered that a dedicated detector is provided in the vehicle, for example. However, when a new dedicated detector is installed, various problems such as difficulty in securing the dedicated detector mounting space, complicated device configuration, complicated control program, and decrease in reliability due to increase in the number of parts are caused. It was expected to occur, and it was not a complete improvement plan.

Thus, for example, it is extremely difficult to make a clear distinction between the case where the active control of the stabilizer should be stopped and the case where the active control of the stabilizer should be continued, such as a so-called stuck state. There was still room for improvement in order to continue control smoothly.

The present invention, when the active control of the stabilizer is being performed, when the vehicle speed detected by the vehicle speed sensor of the vehicle and the steering angle detected by the steering sensor do not accurately reflect the traveling state of the vehicle, for example, when shifting to a so-called stack state. ,
An object of the present invention is to provide a stabilizer control device capable of suitably controlling rolling of a vehicle caused by over-control of a stabilizer.

Configuration of the Invention [Means for Solving the Problems] The present invention, which has been made to solve the above problems, is, as illustrated in FIG. 1, a stabilizer that connects both unsprung members that support left and right wheels of a vehicle. The twist amount adjusting means M1 for adjusting the twist amount of the vehicle according to an external command, the vehicle speed detecting means M2 for detecting the vehicle speed of the vehicle, the steering angle detecting means M3 for detecting the steering angle of the vehicle, and the stabilizer. Control for outputting a command to the twist amount adjusting means M1 to change the twist amount of the target twist amount determined according to the vehicle speed detected by the vehicle speed detecting means M2 and the steering angle detected by the steering angle detecting means M3. A stabilizer control device comprising means M4, further comprising: lateral acceleration detection means M5 for detecting lateral acceleration of the vehicle; vehicle speed detected by the vehicle speed detection means M2; and steering angle detection means M3. Estimated lateral acceleration calculating means M6 for calculating the estimated lateral acceleration of the vehicle from the steering angle that is output, and the difference between the estimated lateral acceleration calculated by the estimated lateral acceleration calculating means M6 and the lateral acceleration detected by the lateral acceleration detecting means M5. Lateral acceleration difference determination means M7 for determining whether or not
When the lateral acceleration determining means M7 determines that the difference between the estimated lateral acceleration and the lateral acceleration is a predetermined value or more,
The stabilizer is characterized by further comprising: a canceling means M8 for outputting to the twisting amount adjusting means M1 an instruction to stop changing the twisting amount of the stabilizer to the target twisting amount commanded by the control means M4. The main point is the control device.

The twist amount adjusting means M1 is for adjusting the twist amount of the stabilizer according to a command from the outside. For example, a cylinder disposed on one of the unsprung member and a mounting portion of the stabilizer facing the unsprung member, and mounted on the other of the unsprung member and the mounting portion of the stabilizer facing the unsprung member. Piston slidably fitted to the cylinder, a hydraulic circuit connecting the upper and lower chambers of the cylinder divided by the piston to a hydraulic pressure source, and a direction switching inserted in the hydraulic circuit It can be realized by a valve and a flow control valve. Further, for example, between the unsprung member and the mounting portion of the stabilizer facing the unsprung member, a cylinder and a piston having a structure similar to a known damping force variable shock absorber are provided, and a control signal input from the outside is formed. Therefore, the piston may be arranged so as to interpose a connection actuator capable of sliding and fixing. Further, for example, the vertical position of the two bearing portions on the left and right where the stabilizer is attached to the vehicle body is changed by the hydraulic actuators disposed on the vehicle body side, or on the vehicle body side near the bearing portion. It is also possible to adopt a configuration using a hydraulic actuator that actively twists the stabilizer. As described above, when the hydraulic actuator is arranged on the vehicle body side, that is, on the spring, the frequency of the sprung vibration is about one digit lower than the frequency of the unsprung vibration. You can improve the property.

The vehicle speed detecting means M2 is for detecting the speed of the vehicle. For example, it can be realized by a reed switch type vehicle speed sensor provided inside the speedometer or an electromagnetic pickup type vehicle speed sensor that detects the rotation speed of the output shaft of the transmission.

The steering angle detecting means M3 is for detecting an excessive steering of the vehicle. For example, it can be realized by a potentiometer which is provided on the steering shaft and outputs a steering amount as an analog signal, or a steering sensor such as a rotary encoder which outputs a digital signal with high resolution.

The control means M4 outputs a command to change the twist amount of the stabilizer to the target twist amount determined according to the vehicle speed and the steering angle. For example, the target twist amount may be calculated based on a map that regulates the relationship between the vehicle speed, the steering angle, and the target twist amount, or based on an arithmetic expression, and a command corresponding to the target twist amount may be output. Further, for example, a stabilizer target capable of determining a moving load between inner and outer wheels in a turning traveling state based on a vehicle speed and a steering angle, and suppressing a vehicle body inclination (so-called rolling) caused by a deflection of a suspension device caused by the moving load. The amount of twist is calculated, and a command to positively twist the stabilizer by the target amount of twist is output.
(So-called Active Control) may be performed.

The lateral acceleration detecting means M5 is for detecting the lateral acceleration of the vehicle. For example, it can be realized by a strain gauge type acceleration sensor arranged near the center of gravity of the vehicle or a servo acceleration sensor.

The estimated lateral acceleration calculating means M6 is for calculating an estimated lateral acceleration of the vehicle from the vehicle speed detected by the vehicle speed detecting means M2 and the steering angle detected by the steering angle detecting means M3. For example, the estimated lateral acceleration can be calculated by dividing the power of the vehicle speed by the steering angle. Alternatively, for example, the estimated lateral acceleration calculated from the vehicle speed and the steering angle may be delayed by a predetermined time according to the time constant to be obtained.

The lateral acceleration difference determining means M7 is for determining whether or not the difference between the estimated lateral acceleration calculated by the estimated lateral acceleration calculating means M6 and the lateral acceleration detected by the lateral acceleration detecting means M5 is a predetermined value or more. . Here, the predetermined value can be set to, for example, a value corresponding to a lateral acceleration difference in the case of a so-called stuck state in which wheels are idling or skid.

The stopping means M8 means the amount of twist of the stabilizer when the difference between the estimated lateral acceleration and the lateral acceleration is determined to be a predetermined value or more by the lateral acceleration difference determining means M7. The instruction to stop the change to is output to the twist amount adjusting means M1. For example, when it is determined that the difference between the estimated lateral acceleration and the lateral acceleration is equal to or greater than a predetermined value, and the steering angle is relatively small, the stabilizer is set to a movable state and is not operated, while the estimated lateral acceleration and When it is determined that the difference from the lateral acceleration is equal to or greater than a predetermined value and the steering angle is relatively large, the stabilizer can be set to a fixed state to exert a torsional elastic force.

The control means M4, the estimated lateral acceleration calculating means M6, the lateral acceleration difference determining means M7, and the stopping means M8 can be realized by, for example, independent discrete logic circuits. Further, for example, a well-known CPU, ROM, RAM, and other peripheral circuit elements may be configured as a logical operation circuit, and each of the above means may be realized according to a predetermined processing procedure.

[Operation] In the stabilizer control device of the present invention, as illustrated in FIG. 1, the control means M4 controls the amount of twist of the stabilizer to detect the vehicle speed detected by the vehicle speed detection means M2 and the steering angle detected by the steering angle detection means M3. When outputting the command to change to the target twist amount determined according to the above, to the twist amount adjusting means M1, the estimated lateral acceleration is calculated from the vehicle speed detected by the vehicle speed detecting means M2 and the steering angle detected by the steering angle detecting means M3. When the difference between the estimated lateral acceleration of the vehicle calculated by the means M6 and the lateral acceleration detected by the lateral acceleration detection means M5 is determined by the lateral acceleration difference determination means M7 to be a predetermined value or more, the amount of twist of the stabilizer, The stopping means M8 functions to output an instruction to stop changing the target twist amount commanded by the control means M4 to the twist amount adjusting means M1.

That is, when the difference between the estimated lateral acceleration calculated from the vehicle speed and the steering angle and the detected lateral acceleration is greater than or equal to a predetermined value,
Assuming that the detected vehicle speed or steering angle does not accurately reflect the actual running state of the vehicle, the amount of twist of the stabilizer was set according to the vehicle speed and steering angle that could be detected incorrectly. The change to the target twist amount is stopped.

Therefore, the stabilizer control device of the present invention, based on the lateral acceleration difference, when it is determined that the vehicle speed of the vehicle or the steering angle does not accurately reflect the actual traveling state of the vehicle, the amount of twist of the stabilizer is adjusted. Stop adjusting the target amount of twist of the stabilizer, which is determined according to the vehicle speed and steering angle, to prevent the amount of twist of the stabilizer from becoming excessively greater than the amount of twist required to suppress rolling of the vehicle. work.

The technical problems of the present invention are solved by the action of each component of the present invention as described above.

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a system configuration of a stabilizer control device which is an embodiment of the present invention.

As shown in FIG. 1, the stabilizer control device 1 includes a front stabilizer device 2 and an electronic control device (hereinafter simply referred to as an ECU) 3 that controls the stabilizer device 2.

The front stabilizer device 2 supplies a connecting actuator 7 interposed between the left mounting portion of the front stabilizer bar 4 and the lower arm 6 of the left front wheel 5 and pressure oil boosted by the hydraulic source 8 to the connecting actuator 7. A connecting unit 10 including a valve actuator 9 for supplying, a right mounting portion of the front stabilizer bar 4 and a right front wheel 11
Stabilizer link connecting between lower arm 12
Equipped with 13.

On the other hand, the left stabilizer and rear rear wheel of the rear stabilizer bar 14
A stabilizer link 17 is provided between the lower arm 16 and the lower arm 16, and a stabilizer link 20 is provided between the right mounting portion of the rear stabilizer bar 14 and the lower arm 19 of the right rear wheel 18.
Are respectively connected by.

The stabilizer control device 1 includes, as detectors, a vehicle speed sensor 21 that detects a vehicle speed, a steering sensor 22 that detects a steering angle, and a lateral acceleration sensor 23 that is arranged near the center of gravity of the vehicle and detects lateral acceleration.

Next, the configurations of the coupling unit 10 and the ECU 3 will be described with reference to FIG. As shown in FIG. 3, the connecting unit 10 includes a connecting actuator 7 that adjusts the distance between the left mounting portion of the front stabilizer bar 4 and the lower arm 6 in accordance with the hydraulic pressure supplied from the valve actuator 9.
It is composed of a stroke sensor 24 that detects the interval (stroke amount) and outputs it to the ECU 3, and a valve actuator 9 that supplies the pressure oil boosted by the hydraulic pressure source 8 to the coupling actuator 7 according to the control of the ECU 3.

In the coupling actuator 7, the piston 32 in which the piston rod 33 is continuously arranged is slidably fitted in the cylinder 31,
The piston 32 divides the inside of the cylinder 31 into an upper chamber 35 having a port 35a and a lower chamber 36 having a port 36a. The piston rod 33 is attached to the left mounting portion of the front stabilizer bar 4, while the cylinder 31
Are mounted on the lower arms 6, respectively. Therefore, the stabilizer device 2 is moved by the movement of the piston 32 of the connecting actuator 7 over a predetermined stroke amount.
It is configured to change the torsional rigidity of the front stabilizer bar 4.

The hydraulic power source 8 also includes a constant-flow hydraulic pump 53 driven by the output shaft 52 of the engine 51 and a reservoir 54 that stores hydraulic oil.

Further, the valve actuator 9 outputs from the ECU 3 and the direction switching valve 41 (four-port three-position solenoid valve) that switches to the fixed position 41a, the contracted position 41b, and the extended position 41c according to the control signal output from the ECU 3. Flow rate control valve (linear solenoid valve) 42 for continuously changing the opening according to the duty ratio control signal. Here, the flow rate control valve 42 is a pipe line 61 connecting the hydraulic power source 8 and the direction switching valve 41.
And a conduit 62 that connects the direction switching valve 41 and the reservoir 54 to each other. In addition, the flow control valve
42 is switched at high speed between the communication position 42a and the blocking position 42b according to the duty ratio control signal output from the ECU 3, and the opening area thereof is changed from the fully open state (communication position 42a) to the fully closed state (blocking position). It is continuously adjustable up to 42b). In the present embodiment, the flow rate control valve 42 is fully opened when the duty ratio control signal is 100 [%], while the flow rate control valve 42 is fully closed when the duty ratio control signal is 0 [%]. I decided to.

As shown in the figure, the ECU 3 described above includes CPU3a, ROM3b, RAM3
It is configured as a logical operation circuit centering on c, and the common bus 3d
It is connected to the input unit 3e and the output unit 3f via the to input and output with the outside. The detection signals of the above sensors are input to the CPU 3a via the input unit 3e, while the CPU 3a outputs control signals to the direction switching valve 41 and the flow rate control valve 42 via the output unit 3f.

The ECU 3 outputs the control signals to the direction switching valve 41 and the flow rate control valve 42 to operate the connecting unit 10 having the above-described configuration as follows.

That is, when the direction switching valve 41 is switched to the fixed position 41a and the flow rate control valve 42 is in the fully open state (communication position 42a) by the control signal of the duty ratio 100 [%],
The hydraulic oil returns to the reservoir 54 via the hydraulic pump 53, the conduit 61, the direction switching valve 41, the flow rate control valve 42, and the conduit 62. Further, the hydraulic circuit that connects the upper chamber 35 and the lower chamber 36 of the cylinder 31 of the coupling actuator 7 is cut off. For this reason,
The piston 32 is fixed at the current position, and the interval (stroke amount) between the front stabilizer bar 4 and the lower arm 6 is maintained at a constant interval, which is a so-called hold state.

On the other hand, when the direction switching valve 41 is switched to either the contracted position 41b or the expanded position 41c, and the flow rate control valve 42 is in the fully open state (communication position 42a) by the control signal of the duty ratio 100 [%]. The hydraulic oil supplied from the hydraulic pump 53 is supplied to the pipeline 61, the direction switching valve 41 and the flow control valve 4
2. Return to reservoir 54 via line 62. Further, the upper chamber 35 and the lower chamber 36 of the cylinder 31 of the connecting actuator 7 described above.
The hydraulic oil inside flows out to the reservoir 54 via the direction switching valve 41, the flow rate control valve 42, and the pipe line 62. Therefore, the piston 32 moves slidably, and the so-called free state in which the interval (stroke amount) between the front stabilizer bar 4 and the lower arm 6 constantly changes.

Further, when the direction switching valve 41 is in the contracted position 41b or the expanded position 41c, and the flow rate control valve 42 is duty ratio controlled so as to gradually reduce the opening degree from the communication position 42a to the cutoff position 42b, the operation is performed. The oil is connected to the actuator 7 via the hydraulic pump 53, the pipeline 61, the direction switching valve 41, and the port 35a.
Of the connecting actuator 7 through the upper chamber 35 of the upper chamber 35 or the port 36a, while the hydraulic oil inside the upper chamber 35 or the lower chamber 36 is supplied to the port 35a or the port 36a, respectively. , And flows out to the reservoir 54 via the direction switching valve 41 and the conduit 62. At this time, since the flow resistance of each flow passage changes according to the opening degree of the flow rate control valve 42 that is gradually closed, the flow rate of the hydraulic oil changes according to the flow resistance,
The moving speed of the piston 32 also changes. Therefore, the piston 33 of the coupling actuator 7 moves by the target stroke determined by the ECU 3, and is detected by the stroke sensor 24.
When the distance (stroke amount) between the left mounting portion of the front stabilizer bar 4 and the lower arm 6 becomes equal to the target stroke amount, a duty ratio control signal for keeping the opening of the flow control valve 42 constant is output. As a result, the connecting actuator 7 changes its entire length by the target stroke amount, and is in the extended state or the contracted state.
The hydraulic pressure generated by the throttle effect when the hydraulic oil supplied from the valve passes through the flow control valve 42 and the acting force applied to the connecting actuator 7 are held in balance. Therefore, the stabilizer bar 4 exerts a twisting action force, and rolling of the vehicle can be suppressed.

Next, the stabilizer control processing executed by the ECU 3 is executed in the fourth step.
An explanation will be given based on the flowcharts shown in FIGS. This stabilizer control processing is executed when the ECU 3 is started. First, in step 100, a process of reading the vehicle speed V, the steering angle θ, and the lateral acceleration G1 is performed. In the following step 110, the vehicle speed V read in the above step 100
, It is determined whether the vehicle speed exceeds the reference vehicle speed V1. If the determination is affirmative, the step 120 is performed, while if the determination is negative, the step 1
Go to 90 each. Here, the reference vehicle speed V1 is a minute speed corresponding to stopping and slowing of the vehicle. In step 120, which is executed when it is determined that the vehicle is running, the above step 1
Estimated lateral acceleration from steering angle θ and vehicle speed V read at 00
A process of calculating G0 as in the following equation (1) is performed.

G0 = h (θ, V) (1) However, the function h defines the relationship in which the power of the vehicle speed V is divided by the product of the steering angle θ and the constant α. Subsequent steps
At 130, a process of performing a filter calculation on the estimated lateral acceleration G0 calculated at step 120 to calculate a corrected estimated lateral acceleration G0F is performed. This filter operation is generally
After the vehicle starts to turn and a predetermined delay time elapses, lateral acceleration corresponding to various conditions at the time of turning is generated, so that the estimated lateral value is calculated by a time constant having a predetermined relationship with the delay time. This is performed in order to calculate the corrected estimated lateral acceleration G0F by delay-correcting the generation time of the acceleration G0. Next, in step 140, it is determined whether the difference between the corrected estimated lateral acceleration G0F calculated in step 130 and the lateral acceleration G1 read in step 100 is the upper limit value C1 or more, and an affirmative judgment is made. And step 150, while if negative, step 1
Go to 90 respectively. Here, the upper limit value C1 is a relatively large value, and is set to determine whether or not the vehicle is in a traveling state corresponding to a so-called stuck state. Step 1 to be executed when the above step 140 is answered in the affirmative
At 50, it is determined whether or not the absolute value of the steering angle θ read at step 100 is equal to or greater than the reference steering angle θ0 [deg]. Proceed to step 170. In step 160 executed when it is determined that the absolute value of the steering angle θ is equal to or greater than the reference steering angle θ0 [deg], the directional control valve 41 is set to the fixed position 4.
After outputting the control signal for switching to 1a, the process proceeds to step 190. On the other hand, the absolute value of the steering angle θ is equal to the reference steering angle θ0 [de
Step 1 to be executed when it is determined to be less than g]
At 70, a process of outputting a control signal for switching the direction switching valve 41 to the contracted position 41b or the expanded position 41c is performed. Next, the routine proceeds to step 180, where after the processing for outputting the duty ratio control signal for fully opening the flow rate control valve 42 is performed, the routine proceeds to step 190.

In step 190, the vehicle speed V, the steering angle θ, and the lateral acceleration G1 are read again. In the following step 200, a process of calculating the estimated lateral acceleration G0 from the steering angle θ and the vehicle speed V read in step 190 is performed as in the above equation (1). In the following step 210, a process of performing a filter calculation on the estimated lateral acceleration G0 calculated in the above step 200 to calculate a corrected estimated lateral acceleration G0F is performed. Next, in step 220, it is determined whether the difference between the corrected estimated lateral acceleration G0F calculated in step 210 and the lateral acceleration G1 read in step 190 is less than the lower limit value C2, and an affirmative determination is made. Then, the process proceeds to step 230, and on the other hand, if a negative determination is made, the process returns to step 150. Where the lower limit value C
2 is a value smaller than the upper limit value C1 and is set to determine whether or not the so-called stacked state has ended. In step 230, which is executed when an affirmative determination is made in step 220, processing for calculating the target stroke amount SG as in the following equation (2) is performed.

SG = f (V, θ) (2) where f is a predetermined function.

The target stroke amount SG is, for example, the lateral acceleration of the vehicle.
It may be calculated by multiplying G1 by a constant, or may be calculated, for example, according to a map created from the values calculated in advance for the vehicle speed V and the steering angle θ.
In the following step 240, the duty ratio D of the flow control valve 42
Is calculated according to the following equation (3).

D = g (SG) (3) where g is a function.

In the following step 250, a process of reading the current stroke amount S detected by the stroke sensor 24 is performed. Next, at step 260, the stroke amount S read at step 250 is within a predetermined range including the target stroke amount SG (SG
± ΔSG) is determined, and if a positive determination is made, it is determined that the stroke amount S does not need to be adjusted.
On the other hand, if the determination is negative, the process proceeds to step 270. In step 270, which is executed when it is determined that the stroke amount S still needs to be adjusted, the direction switching valve 41 is switched so that the current stroke amount S becomes the target stroke amount SG calculated in step 230. A process of outputting a control signal is performed. In the following Step 280, the above Step 2
After performing the process of outputting the duty ratio control signal calculated in 40 to the outflow control valve 42, the process returns to step 250. On the other hand, in step 290, which is executed when it is determined in step 260 that the stroke amount S does not need to be adjusted anymore, a process of outputting a duty ratio control signal for holding the opening degree of the flow control valve 42 is executed. After this, the present stabilizer control processing is temporarily terminated. After that, the present stabilizer control processing repeats the above steps 100 to 290 at predetermined time intervals.

In the present embodiment, the hydraulic pressure source 8 and the connecting unit 10 serve as the twist amount adjusting means M1, and the vehicle speed sensor 21 serves as the vehicle speed detecting means M2.
The steering sensor 22 corresponds to the steering angle detecting means M3. Further, the steps (230 to 290) of the ECU3 and the processing executed by the ECU3 function as the control means M4. Further, the lateral acceleration sensor 23 corresponds to the lateral acceleration detecting means M5, and the steps (120 to 130) in the ECU3 and the processing executed by the ECU3 serve as the estimated lateral acceleration calculating means M6, and the step (140) serves as the lateral acceleration difference determination. As means M7, step (1
50, 160, 170, 180) respectively function as the stopping means M8.

As described above, according to this embodiment, for example, a so-called stuck state, which is likely to occur on a wet descent surface or a snowy road surface having a low friction coefficient, the vehicle speed detected due to idling of the drive wheels or skidding of each wheel. And the case where the steering angle does not accurately reflect the running state of the vehicle is accurately determined, and the active control of the stabilizer is stopped. Therefore, the occurrence of rolling, which is a harmful effect due to overcontrol due to the active control execution of the stabilizer, occurs in advance. Can be prevented. Therefore, the occupant does not feel uncomfortable and the riding comfort is further enhanced.

In addition, it becomes possible to accurately grasp the shift to the so-called stack state, and it is possible to accurately determine whether the active control of the stabilizer is effective as the control of the vehicle attitude or whether it is to be stopped because it causes harmful effects. Therefore, only when the active control of the stabilizer is effective, the active control can be executed to achieve desired effects such as improved maneuverability and stability.

Furthermore, when canceling the suspension of the active control of the stabilizer, the difference between the corrected estimated lateral acceleration G0F and the lateral acceleration G1 is set to be less than the lower limit C2 which is set smaller than the upper limit C1. Since the active control of the stabilizer is restarted after the stack state is completely ended, rolling of the vehicle that occurs due to the sudden restart of the active control can be suppressed and hunting accompanying the control can be prevented. This is because, for example, as a result of sudden acceleration or a large steering operation, the active control is not suddenly restarted at the end of the so-called stuck state, and a sudden vibration in the roll direction is not generated in the vehicle. It is valid.

Further, since it is not necessary to provide a detector for detecting the peripheral speed of the wheel or the angular velocity of rotation under the spring, wiring of various cables connected from the unsprung to the sprung is unnecessary, and the detection can be performed. Since the device is not directly affected by unsprung vibration with a high frequency, the durability and reliability of the device are improved.

Further, it is not necessary to dispose a dedicated sensor or the like for accurately detecting the start of the so-called stuck state as described above, and the existing vehicle speed sensor, steering sensor and lateral acceleration sensor are used, so that the vehicle Since no major remodeling of the device is required, it is possible to downsize the device, simplify the configuration, simplify the control program, and reduce the number of parts, maintain the versatility of the device, and improve the control accuracy and reliability. A high stabilizer active control can be realized.

In addition, in this embodiment, when a so-called stuck state is encountered,
When the absolute value of the steering angle θ is equal to or greater than the reference steering angle θ0 [deg], the directional control valve 41 is switched to the fixed position 41a, while the absolute value of the steering angle θ is less than the reference steering angle θ0 [deg]. When the directional control valve 41 is in the contracted position 41b, or
The flow control valve 42 is fully opened while switching to the extended position 41c. Therefore, in a so-called stacked state,
When the occupant is steering, the coupling actuator 7 can be held in a fixed state to avoid the occurrence of rolling as much as possible. On the other hand, when the occupant is not steering, the coupling actuator 7 can be kept in a movable state to cause active control. It is possible to prevent rolling.

Further, the estimated lateral acceleration G0F calculated from the vehicle speed and the steering angle is delayed by a time constant having a predetermined relationship with the delay time from the start of turning the vehicle to the occurrence of lateral acceleration to correct the estimated lateral acceleration G0F. By performing a filter calculation to calculate, the subsequent lateral acceleration difference determination using the corrected estimated lateral acceleration G0F, it is possible to accurately calculate the lateral acceleration that occurs after a predetermined delay time from the start of turning of the vehicle,
The determination accuracy of the vehicle traveling situation and the control accuracy based on the determination are also improved.

In the present embodiment, the connecting actuator 7 is arranged only on the left front wheel side, but it is arranged, for example, on the left and right front wheels or on all four wheels, and each connecting actuator is controlled independently. You may. Even when such a configuration is adopted, the same effect as that of the above-described embodiment can be obtained.

Further, in the present embodiment, it is determined whether or not the so-called stack state is based on the lateral acceleration difference obtained by subtracting the lateral acceleration G1 from the corrected estimated lateral acceleration G0F. Use the lateral acceleration difference obtained by subtracting the estimated lateral acceleration G0F or the lateral acceleration difference obtained by taking the absolute value of the difference between the corrected estimated lateral acceleration G0F and the lateral acceleration G1. Even if the determination is made based on the set lateral acceleration difference, the same effect as that of the above-described embodiment is exhibited.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention. .

As described above in detail, the stabilizer control device of the present invention is
When the difference between the estimated lateral acceleration calculated from the vehicle speed and the steering angle and the detected lateral acceleration is equal to or greater than a predetermined value, the detected vehicle speed or the steering angle accurately reflects the actual running state of the vehicle. If not, it is configured to stop changing the twist amount of the stabilizer to the target twist amount that is determined according to the vehicle speed and the steering angle that may be incorrectly detected. Therefore, for example, it is possible to extremely accurately determine that the rotation speed of the drive wheels of the vehicle has changed to a state where the rotation speed of the drive wheels does not accurately reflect the vehicle speed due to idling of the drive wheels of the vehicle, such as a so-called stuck state, and When such a state is entered, the normal active control is temporarily stopped, and the occurrence of rolling due to overcontrol of the stabilizer twist amount to an excessive value larger than an appropriate value is ensured by continuing the active control. It has an excellent effect that it can be prevented.

Also, since it is possible to accurately grasp the transition to the so-called stack state, there is no erroneous judgment when deciding whether to execute the normal stabilizer active control or to cancel it, and execute it only when the stabilizer active control is effective. it can. That is, for example, even when the drive wheels start to idle, it is possible to accurately determine whether the idle wheels are temporary in a sudden acceleration state or due to a transition to a so-called stack state. Therefore, it is possible to accurately determine the running state of the vehicle, and based on the wrong decision, the active control is stopped even at the effective time, and the vehicle returns to cause a malfunction. Can be avoided.

From each of the above-mentioned effects, without giving the occupant a feeling of strangeness,
The remarkable advantage is that the riding comfort is also improved.

Further, in order to accurately detect the so-called stuck state as described above, for example, it is not necessary to mount a dedicated detection unit for detecting the rotational states of the drive wheel and the idle wheel on the lower spring portion of the vehicle where the vibration frequency is high. Therefore, it is not necessary to remodel the vehicle significantly, and the existing detection means for detecting the vehicle speed, steering angle, and lateral acceleration can be used. Therefore, it is difficult to secure the mounting space due to the addition of the dedicated detection means. Reliability, durability, and versatility, and the control accuracy is high, without causing various adverse effects such as inferiority, complicated device configuration, complicated control program, and increased number of parts. It is also possible to realize highly reliable active control of the stabilizer.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram conceptually illustrating the content of the present invention, FIG. 2 is a system configuration diagram of an embodiment of the present invention, and FIG. 3 is an explanation showing a configuration of a hydraulic circuit and an electronic control unit thereof. FIGS. 4A and 4B are flowcharts showing the same control. M1 …… Twist amount adjusting means M2 …… Vehicle speed detecting means M3 …… Steering angle detecting means M4 …… Control means M5 …… Lateral acceleration detecting means M6 …… Estimated lateral acceleration calculating means M7 …… Lateral acceleration difference judging means M8… … Canceling means 1 …… Stabilizer control unit 3 …… Electronic control unit (ECU) 3a …… CPU 8 …… Hydraulic power source 10 …… Coupling unit 21 …… Vehicle speed sensor 22 …… Steering sensor 23 …… Lateral acceleration sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidenori Ichimaru 1st Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Toshio Onuma 1st Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation ( 72) Inventor Osamu Yasuike 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References JP-A-63-173711 (JP, A) JP-A-63-149211 (JP, A)

Claims (1)

[Claims] 1. A twist amount adjusting means for adjusting a twist amount of a stabilizer connecting both unsprung members supporting left and right wheels of a vehicle according to a command from the outside, and a vehicle speed detecting means for detecting a vehicle speed of the vehicle. The steering angle detecting means for detecting the steering angle of the vehicle and the twist amount of the stabilizer are set to a target twist amount determined according to the vehicle speed detected by the vehicle speed detecting means and the steering angle detected by the steering angle detecting means. A stabilizer control device comprising: a control unit that outputs a command to change to the twist amount adjusting unit; and a lateral acceleration unit that detects a lateral acceleration of the vehicle, and a vehicle speed detected by the vehicle speed detecting unit. And an estimated lateral acceleration calculation means for calculating an estimated lateral acceleration of the vehicle from the steering angle detected by the steering angle detection means, and an estimated lateral acceleration calculated by the estimated lateral acceleration calculation means. Lateral acceleration difference determining means for determining whether or not a difference between the velocity and the lateral acceleration detected by the lateral acceleration detecting means is a predetermined value or more; and the lateral acceleration difference determining means for estimating the lateral acceleration and the lateral acceleration. When it is determined that the difference is greater than or equal to a predetermined value, the canceling means for outputting to the twisting amount adjusting means an instruction to stop changing the twisting amount of the stabilizer to the target twisting amount commanded by the control means. A stabilizer control device comprising: