JP3377115B2 - Method and apparatus for closed-loop and / or open-loop control of a closed-loop and / or open-loop controllable chassis - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a closed-loop and / or open-loop controllable chassis for a motor vehicle.
Further, the present invention relates to an open loop control method and apparatus.

[0002]

2. Description of the Related Art Chassis design is important in order to improve the driving comfort of passenger vehicles and / or commercial vehicles. In the passive chassis that has been widely used to date, the suspension system between the vehicle body and the wheels is
At the time of installation, it is set to a hard tendency (“sports type”) or a soft tendency (“comfort emphasis”). In this system, the chassis characteristics cannot be adjusted during driving.

On the other hand, in the case of an active chassis, the characteristics of the suspension system can be adjusted during driving by open-loop control or closed-loop control according to the driving conditions.

In order to open-loop or close-loop control an active chassis of this kind, a suspension system is driven so as to exert a force between wheels and a vehicle body in accordance with the running state of the vehicle. That is, for example, for a vehicle occupant or a load sensitive to impact, the motion of the vehicle body is perceived as impairing traveling comfort. The causes of this type of vehicle body movement include excitation by road surface irregularities, and further changes in the running state due to steering, braking and acceleration.

In particular, it is important to effectively offset the rolling movement of the vehicle body caused by the steering movement of the vehicle. In that case, ideally, the suspension system is driven such that the induced roll torque is compensated.

EP-0237919 and EP-
In the chassis closed loop control system described in Japanese Patent No. 0345816, the roll torque caused by the steering operation is canceled by using, for example, a steering angle sensor signal. However, satisfactory rolling compensation cannot be obtained by the methods described in these publications. This is particularly because, for example, in EP0237919 in which a preset value is obtained from the end value of the roll angle that is constantly predicted and the actual roll angle, the dynamic characteristics of the roll or the swing motion are not considered. is there. Furthermore, in these systems, it is necessary to know the roll angle at that time.

[0007] Also, Lang, Wa
lz) publication "Active roll motion reduction (Act
IVE Roll Reduction ”EAEC 91059 describes an active stabilizer for reducing rolling.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical standpoint, and an object of the present invention is to provide a simple method and apparatus without any need to know the roll angle. A new and improved vehicle closed-loop and / or open-loop control capable of dynamically and dynamically compensating for rolling motion of a vehicle without unexpectedly affecting yawing motion. A method and apparatus for closed-loop and / or open-loop control of a chassis.

[0009]

In order to solve the above-mentioned problems, according to the invention as set forth in claim 1, closed-loop and / or open-loop control of an automobile using an actuator arranged between a vehicle body and wheels. In the case of closed-loop and / or open- loop control of the possible chassis, the signal deltaSW representing the steering angle of the vehicle is detected. Furthermore, this steering angle signal is then processed by the processing unit. It that case Importantly, roll angle and low processing unit
According to the vehicle longitudinal speed (Vx) only, independent of the amount of displacement
Changing dynamic transfer characteristic G (s, Vx) the method comprising having, where the variable s is a Laplace variable describing the time response of the unit. The actuator is driven according to the result of this processing.

According to the second aspect of the invention, as the transfer characteristic (G (s, Vx)) of the processing unit (12), (G (s, Vx)) = (Zi * s ⁱ ) / ( Ni * s ⁱ ) can be used. The variable s then represents the Laplace variable describing the time response of the unit and is related to at least one of the coefficients Zi and / or Ni of the vehicle longitudinal speed (Vx).

According to a third aspect of the present invention, the result of the processing is configured to represent a roll torque to be applied by the actuator between the vehicle body and the wheels for reducing rolling of the vehicle body.

According to the fourth aspect of the present invention, particularly when the actuator is driven, the roll torque caused by the curved traveling of the vehicle is compensated for the purpose of closed loop or open loop control.

According to the fifth aspect of the present invention, the first means for detecting the first signal indicating the steering angle of the vehicle and the first signal do not depend on the roll angle and the roll displacement amount. To
A closed-loop and / or open-loop control of a vehicle, the processing unit processing according to a dynamic transmission characteristic that changes only according to a vehicle longitudinal speed (Vx) and driving an actuator according to the processing result. A device for closed-loop and / or open- loop control of possible chassis is provided.

According to the invention described in claim 6, the processing unit (12) has a transfer characteristic (G (s, Vx)) = (Zi * s ⁱ ) / (Ni * s ⁱ ), Where the variable s is a Laplace variable describing the time response of the unit, and the coefficient of vehicle longitudinal velocity (Vx) Zi and / or detected by the second means (13).
Alternatively, it is configured to relate to at least one of Ni.

According to a seventh aspect of the invention, the above device is applied to a vehicle in which each wheel unit of the vehicle is provided with an actuator.

According to the invention of claim 8, an active stabilizer is driven as the actuator.

[0017]

According to the method and the apparatus of the present invention configured as described above, the actuators arranged between the vehicle body and the wheels for compensating the rolling are driven in the correct phase, whereby the vehicle of the vehicle is driven. The advantage is that rolling can be reduced both steadily and during the dynamic steering process. In that case, it is not necessary to know the roll angle.

[0018]

EXAMPLES The method of the present invention will be described in detail with reference to the examples described below. Therefore, the vehicle "system" is shown in Fig.
Are shown in a block diagram. The vehicle 21 has a steering angle delta shown in FIG.
It responds to the driver's steering operation described as SW and the active control roll torque Mw which is unknown at this time but can be input. The roll torque Mw is the rotation about the vertical axis having the yawing speed wz,
With lateral velocity Vy and rolling with roll angular velocity psi integrated into roll angle phi. Further, the roll torque Mw is a roll torque provided by an actuator arranged between the vehicle body and the wheels, and acts in addition to the roll torque generated by the centrifugal force. This roll torque M
w can be adjusted in the active chassis. In connection with this, in the vehicle 21 shown in FIG. 2, only the transition of the roll angle or the roll speed becomes a problem. These variables are obtained from the steering angle deltaSW and the roll torque Mw according to the following transfer function: G1 (s, Vx) = phi (s) / deltaSW (s) (1) and G2 (s, Vx) = phi (s). ) / Mw (s) (2)

In order to separate the rolling from the steering movement, a filter (transfer characteristic G (s, Vx)) for determining the roll torque Mw from the steering angle deltaSW is introduced.
In an ideal case, the roll torque Mw obtained in this way compensates for the roll torque generated by the centrifugal force during traveling on a curve. This method is clarified in FIG.

In this case, the vehicle 31 has a steering angle delta.
In addition to SW and the vehicle longitudinal speed Vx, the roll torque Mw provided by the actuator acts. The roll torque input in this way, that is, the roll torque Mw applied by the actuator, is obtained by processing the detected steering angle signal deltaSW by the processing unit 32 or 12 (FIG. 1). This processing unit is characterized by its dynamic transfer characteristic G (s), where the variable s is a Laplace variable that describes the time response of the unit. This kind of transfer characteristic is represented by the transfer function G (s, Vx) as follows: G (s, Vx) = (Zi * s ⁱ ) / (Ni * s ⁱ ) where the transfer function G (s , Vx) coefficients Zi and /
Or Ni is a function of the vehicle longitudinal velocity Vx supplied to the units 32-12.

As in FIG. 2, the transfer functions G1 (s, Vx) and G2 (s, Vx) in FIG. 3 represent the vehicle characteristics in response to the steering action exerted by the driver and the roll torque exerted by the actuator. Represent An important vehicle response related to this is rolling of the vehicle body, here the roll angle phi
Represented by

First, the roll angle phi is obtained according to the following relationship: phi (s) = [G1 (s, Vx) * deltaSW (s)] + [G2 (s, Vx) * Mw (s)] = [ G1 (s, Vx) * deltaSW (s)] + [G2 (s, Vx) * G (s, Vx) * deltaSW (s)] = [G1 (s, Vx) + G2 (s, Vx) * G (s, Vx)] * deltaSW (s) (3)

In order to keep the roll angle phi always equal to zero, irrespective of the change in steering angle (ie so that the vehicle body stabilizes), the following equation must hold: G (s, Vx) =-[G1 (s, Vx) / G2 (s, Vx)] (4)

Therefore, the roll torque can be obtained as a function of the steering angle transition. Mw (s) = G (s, Vx) * deltaSw (s) (5) Transfer functions G1 (s, Vx) and G2 (s, Vx) ) Is defined according to vehicle parameters using the following formula:

[0025]

[Equation 1]

In the following, the transfer characteristic G (x, Vx) will be specified for specific vehicle parameters. Definition of system parameters: Ma = vehicle body mass MF = chassis mass IAX = vehicle body inertial moment IAZ about vehicle vertical axis (roll axis) = vehicle body inertial moment IFZ centered on vehicle vertical axis (yaw axis) = Moment of inertia of the chassis HM about the vertical axis of the vehicle (yaw axis) = Distance of the roll axis from the road surface HS = Distance of the center of gravity of the vehicle from the roll axis LV = Distance from the center of gravity of the front axle LH = Center of gravity of the rear axle Distance from SV = Front wheel distance SH = Rear wheel distance LW = Distance from the center of gravity of the side wind force acting point CAV = Front lateral strength CAH = Rear lateral strength KFV = Spring strength of front body spring KFH = Spring strength of rear body spring DFV = front damper parameter DFH = rear damper parameter G = gravitational acceleration

The following values are assumed for the parameter values: Ma = 1661.0000Kg MF = 186.00000Kg IAX = 599.00000Kg * m ² IAZ = 3000.0000Kg * m ² IFZ = 710.00000Kg * m ² HM = 0.1000 m HS = 0.4500 m LV = 1.5067 m LH = 1.3433 m SV = 1.5280 m SH = 1.5400 m LW = 0.2000 m CAV = 63835.0000 N / rad CAH = 64356.0000 N / rad KFV = 16374.0000 N / m KFH = 17307.0000 N / m DFV = 222.7000 N * s / m DFH = 2246.3000 N * s / m G = 9.8100 m / s ²

[0028] The following transfer function is obtained for this parameter: G (s, Vx) = {s 2 * (- 0.2042 * Vx 2) + s * (- 1.0152 * Vx 3 -27.12 * Vx + 1.35 * 10 - ⁵ ) + (-20.19 * Vx ² -0.0019)} / {s ² * (6.06 * 10 ^-6 * Vx ² ) + s (0.0017 * Vx) + (-3.1878 * 10 ^-5 * Vx + 0.1181)}

The general form already mentioned is recognized here: G (s, Vx) = (Zi (Vx) * s ⁱ ) / (Ni (Vx) * s ⁱ ).

FIG. 1 shows a block circuit diagram of the method according to the invention. A steering angle detector 1 for measuring an operation angle of a steering wheel which is preferably operated by a driver
1 gives the signal deltaSW representing the steering angle of the vehicle. This signal deltaSW is supplied to the dynamic filter unit 12. Further, the vehicle longitudinal speed detected by the sensor 13 is applied to the filter unit 12 by the signal Vx.
Supplied in the form of. In that case, the filter unit 12
The transfer characteristic of corresponds to the transfer function G (s, Vx) described above. A signal Mw is output at the output of the filter unit 12, which signal indicates the roll torque to be produced by the actuator 15ij.

In the present embodiment shown in FIG. 1, it is assumed that an actuator 15ij is provided in each wheel unit in a four-wheel vehicle. In addition,
The index i indicates the axis, and the index j indicates the left and right sides to which the vehicle actuator is attached. The desired roll torques Mw are converted in the unit 14 into target forces for the individual actuators 15ij in order to provide the forces and generate the desired roll torques Mw by the four actuators 15ij. The transfer characteristics of the unit 14 are generally shown as a force distribution matrix that is easily obtained from the vehicle geometry. A force distribution matrix of this kind is described, for example, in German patent application P4217325.
See No. 6 publication. Signal fi representing each target force
By driving the actuator 15ij with js, a desired roll torque Mw of the vehicle body is produced, and this target torque acts so as to cancel the roll torque produced by the curve running.

In the method of the present invention, the filter unit 1
Two dynamic designs are important. This makes it possible to drive the actuator in phase for vibration compensation, so that rolling of the vehicle body can be reduced both in the steady state and in the dynamic steering process.

The effects obtained by the above-mentioned control are clearly shown in FIGS. This effect is
It becomes clear when the reaction of the vehicle or the movement of the vehicle body is observed when the steering angle changes abruptly. This type of abrupt change in steering angle is characterized by a steering angle curve starting from 0 ° and reaching a maximum steering angle of 1 ° at the front wheels of the vehicle. FIG. 4 shows the temporal transition of this kind of sudden change in the steering angle.

A conventional passively designed vehicle chassis reacts to this type of steering operation at a roll angle phi shown in FIG. 5 (a) for a time t. 4 to 11, the axes are shown in arbitrarily selected units [a, u]. The passively designed vehicle chassis further reacts to this steering operation at the yawing speed wz shown in FIG. 5 (b). In FIG. 5 (b), rolling or obvious yawing movements of the vehicle body can be seen.

In order to constantly reduce the roll angle phi to zero, the roll torque Mw shown in FIG. 6 is required. This roll torque is expressed by the static component of the equation (4) and the equation (5).
Obtained from When the obtained roll torque is input to the actuator so as to correspond to the curve shown in FIG. 6, the transition (curve 2) shown in FIG. 7 is obtained. For comparison, FIG. 7 shows the roll angle curve 1 when no other rolling component is added (for chassis designed passively). However, the roll angle is vibrated clearly in the transfer characteristic by the addition of the torque constantly obtained (curve 2 in FIG. 7), and thereby the yaw speed wz is also vibrated. This is the curve 2 in FIG. 7 for the roll angle, and the curve 1 (dotted line) in FIG. 8 for the yawing speed wz.
Is shown in. As a comparison thereto, the yawing speed when no other rolling component is added is shown in the curve 2 of FIG. As described above, in the conventional method, regarding the transition of the yawing speed, it is understood that the yawing characteristic is deteriorated by adding the static rolling component.

On the other hand, according to the present invention, the actuator is driven so that the roll torque determined according to the equations (4) (having dynamic elements) and (5) is applied as a whole. . This torque is shown in FIG. By adding such torque (FIG. 9) according to the present invention, as shown in FIG. 10 (curve 2), it is possible to almost completely compensate for the roll angle that occurs when the steering angle suddenly changes. For comparison, FIG. 10 shows the transition of the roll angle due to the passively designed chassis in curve 1.
Indicated by.

However, as is apparent from FIG. 11, when the roll torque is applied according to the present invention, the above-mentioned drawbacks in forming the yawing speed wz are not present. In the figure, curve 1 (dotted line) shows the change of the yawing speed with the addition of the roll torque according to the present invention, and curve 2 shows the change of the yawing speed due to the passively designed chassis.

The curves shown in FIGS. 10 and 11 thus allow a nearly ideal roll angle compensation by dynamically filtering the steering angle signal deltaSW according to the invention and, accordingly, providing a roll torque by the actuator. Therefore, it is shown that the transition of the yawing speed is not deteriorated as compared with the passively designed chassis.

The roll torque provided by the actuator according to the invention can be distributed differently on the rear or front axle. This kind of roll torque distribution, which in particular adjusts the steering characteristics of the vehicle, is obtained by the special design of the unit 14. The force distribution matrix (unit 4) already mentioned can then be designed for different roll torque distributions which are fixedly adjusted, or for roll torque distribution selectable during driving.
Therefore, in FIG.
0 is supplied. Note that r0 = rear roll torque / front roll torque.

The roll compensation according to the invention is used in a system as follows: -The desired roll torque distribution (r) to adjust the lateral motion characteristics, with roll angle detection controlled to eliminate external noise.
Partially active chassis control system without 0). -Roll angle detection that controls to eliminate external noise and desired roll torque distribution (r
0) Partially active chassis control system with. -Simple partial active chassis control system without roll angle detection and desired roll torque distribution to adjust lateral motion characteristics. A simple partially active chassis control system without roll angle detection, but with the desired roll torque distribution (r0) to adjust lateral motion characteristics. -The desired roll torque distribution (r0) to adjust lateral motion characteristics
Active Stabilizer with and without Active Stabilizer Furthermore, according to the invention, no spring displacement sensor is required to measure the roll angle, so the system is used for a particularly low-cost chassis control system. be able to.

[0041]

As described above, according to the method and the device of the present invention, the actuators arranged between the vehicle body and the wheels are driven in the correct phase to compensate for the rolling motion of the vehicle. This has the advantage that rolling of the vehicle can be reduced both steadily and during the dynamic steering process. In that case, since it is not necessary to know the roll angle, the spring displacement amount sensor for measuring the roll angle can be omitted.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing the method and apparatus of the present invention.

FIG. 2 is a block diagram illustrating a functional method of the present invention using a vehicle model.

FIG. 3 is a block diagram illustrating a functional method of the present invention using a vehicle model.

FIG. 4 is a diagram illustrating the operation of the method of the present invention in the background of the prior art.

FIG. 5 is a diagram illustrating the operation of the method of the present invention in the background of the prior art.

FIG. 6 is a diagram explaining the operation of the method of the present invention in the background of the prior art.

FIG. 7 is a diagram explaining the operation of the method of the present invention in the background of the prior art.

FIG. 8 is a diagram illustrating the operation of the method of the present invention against the background of the prior art.

FIG. 9 is a diagram explaining the operation of the method of the present invention in the background of the prior art.

FIG. 10 is a diagram explaining the operation of the method of the present invention in the background of the prior art.

FIG. 11 is a diagram illustrating the operation of the method of the present invention in the background of the prior art.

[Explanation of symbols]

11 Steering angle detector 12 Filter unit 13 sensors 14 units 15ij actuator

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Claims (8)

(57) [Claims] 1. A method for closed-loop and / or open- loop control of a closed-loop and / or open- loop controllable chassis of a motor vehicle by means of an actuator (15ij) arranged between the vehicle body and wheels. Detecting a first signal (deltaSW) representing a steering angle, the first signal being dependent on the roll angle and the roll displacement.
Without the processing unit (1) having a dynamic transfer characteristic (G (s, Vx)) that changes only according to the vehicle longitudinal speed (Vx).
2) treated with, drives the actuator according to the result of this process (Mw), automotive closed loop and / or open-loop controllable chassis closed and / or open root <br/> flop, characterized in that How to control. 2. The transfer characteristic (G (s, Vx)) of the processing unit (12) is described by G (s, Vx) = (Zi * s ⁱ ) / (Ni * s ⁱ ), in which case Is the Laplace variable describing the time response of the unit, and is at least one of the coefficients Zi and / or Ni of the vehicle longitudinal speed (Vx).
The method of claim 1, wherein the method is associated with one. 3. The result (Mw) of the treatment represents a roll torque to be exerted by the actuator (15ij) between a vehicle body and a wheel in order to reduce rolling of the vehicle body. Or the method described in 2. 4. The method according to claim 1, characterized in that the driving of the actuator (15ij) compensates for the roll torque that occurs when the vehicle is traveling in a curve for closed-loop and / or open-loop control purposes. The method described in. 5. An apparatus for carrying out the method according to claim 1, comprising first means (11) for detecting a first signal (deltaSW) representative of a steering angle of the vehicle, and the first signal. The low
Vehicle longitudinal speed (Vx) independent of the roll angle and roll displacement
Dynamic transfer characteristics (G (s, Vx)) that change depending only on
Processing, characterized in that it comprises a processing unit for driving the actuator (12) in accordance with the processing result (Mw), the closed-loop and / or open loop and / or open-loop controllable chassis of the motor vehicle in accordance with < A device for loop control. 6. The processing unit (12) has a transfer characteristic G (s, Vx) = (Zi * s ⁱ ) / (Ni * s ⁱ ), where the variable s describes the time response of the unit. Of the vehicle longitudinal velocity (Vx) which is a Laplace variable and which is detected by the second means (13).
Or the device according to claim 5, characterized in that it is associated with at least one of Ni. 7. Device according to claim 5, characterized in that each wheel unit of the vehicle is provided with an actuator (15ij). 8. The active actuator as the actuator
Device according to claim 5, characterized in that the stabilizer is driven.