JP2001001794A - Method for driving actuator for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To combine the plurality of control systems for obtaining single common control volume so as to create optimum control conditions under any circumstances. SOLUTION: In this method for driving a vehicle's actuator provided with at least two control systems so as to control a single common control amount, a first control system 1 as a primary system performs basic control by driving a main actuator 6 provided in the first control system 1. A second control system 2 as a secondary system is connected to an auxiliary actuator 7 so as to drive the auxiliary actuator 7 provided in the second control system 2 depending on drive signals to the main actuator 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for driving or triggering an actuator of a motor vehicle having at least two control systems for controlling one common control variable.

[0002]

2. Description of the Related Art Such a control system is known, for example, from DE-A-196 43 197. In this known method, the actuator is driven by two control systems, a four-wheel steering system and an automatic braking system. Thus, during a curve, this known method of controlling the movement of the vehicle in order to improve the stability of the vehicle provides for the control of vehicle variables as a common control variable that is important for lateral stability. However, there is no description of a method or system for connecting the two control systems.

Conventionally (for example, for driving dynamic characteristic control)
The control systems were mounted on the vehicle alone or together without being coupled to each other. The mutual influence between different systems to improve the control of a common control variable (for example yaw rate, sideslip angle or lateral acceleration) has not been considered in the past. However, basically, each control system controls a control amount (for example, a control amount based on a traveling dynamic characteristic) only under a predetermined condition.
Suitable for controlling.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optimum control characteristic under all conditions.
It is to combine a plurality of control systems for one common control variable.

[0005]

This object is achieved by the features of claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

According to the invention, in a method for driving an actuator of a motor vehicle having at least two control systems for controlling a common control variable, a first control system as a primary system is additionally provided. The basic control is performed by driving the main actuator. Depending on the drive signal to the main actuator, the second
Is connected to drive an auxiliary actuator attached to the secondary system.

[0007] In particular, the secondary system outputs a drive signal assigned to the auxiliary actuator without depending on the primary system. This drive signal of the secondary system is guided to the auxiliary actuator from a connection unit controlled by the drive signal to the main actuator.

[0008] In an embodiment of the invention, the connection unit comprises a functional block, which produces a value between 0 and 1 depending on the drive signal to the main actuator. This value is multiplied by the secondary drive signal. The signal determined in this way is supplied to the auxiliary actuator.

For example, the drive signal of the secondary system is guided to the auxiliary actuator when the main actuator is completely driven or gradually from a control threshold value set for the main actuator.

The method according to the invention is also applicable to one or more main and / or auxiliary actuators. Main actuators can be understood as meaning, for example, all operating elements for functions assigned to the primary system, for example front and / or rear axle steering. Similarly, auxiliary actuators can be understood as all operating elements for the functions assigned to the secondary system, for example valves or pumps for wheel-by-wheel brake intervention. The method according to the invention further comprises:
It can be used for more than one control system. Hierarchy under all control systems is important. Thereby, a unique connection of the control system is achievable.

[0011]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, an input signal obtained from a difference between a target value X and a control amount Y is supplied to a primary system 1 and a secondary system 2. The primary system 1 is a first control system that works optimally over as wide a range as possible and under as many conditions as possible. The primary system 1 serves, for example, to control the amount of driving dynamics, in this case, for example, a superimposed front axle steering system, an active rear axle steering system or a rolling moment distribution system. The secondary system 2 is a second control system, which is basically connected when the primary system 1 can no longer produce the control variable Y by itself. This is for example
This is when the actuators of the primary system 1 are fully controlled, thereby reaching their limits. When controlling the dynamic characteristic quantity, such a secondary system 2 is, for example, a brake system that operates for each wheel.

The primary system 1 is a main actuator 6 of an automobile 5
To supply a drive signal. The secondary system 2 supplies drive signals to the auxiliary actuator 7 via connection units (switch-on units) 3 and 4. The secondary system 2 can automatically output such a drive signal, and according to the invention, the connection units 3, 4 determine the guidance of this drive signal to the auxiliary actuator 7. This connection unit comprises a functional block 3 and a multiplication point 4. The multiplication point 4 is arranged between the secondary system 2 and the auxiliary actuator 7. The drive signal of the primary system 1 to the main actuator 6 is also an input signal of the functional block 3 of the connection units 3 and 4. The function block 3 produces a value between 0 and 1 depending on the drive signal to the main actuator 6. This value is multiplied by the driving signal of the secondary system 2 at a multiplication point 4. The signal thus generated is further supplied to the auxiliary actuator 7.

For example, the control signal of the secondary system 2 is guided to the auxiliary actuator 7 when the main actuator 6 is completely controlled (FIG. 2) or gradually from a set control threshold value of the main actuator 6 (FIG. 3). Is done.

In FIG. 2, the control range of the main actuator 6 (for example, an actuator for changing the steering angle) is written in a positive range and a negative range starting from the zero position on the abscissa. When the main actuator 6 is completely controlled in a positive range (position G1 _p ) (eg, maximum steering to the right) or in a negative range (position G1 _n ) (eg, maximum steering to the left), the main actuator 6 is completely controlled. Then, the value of the function block 3 is set from 0 to 1. As a result, the drive signal of the secondary system 2, which is initially set to zero by the multiplication point 4, is guided unchanged to the auxiliary actuator 7, for example, the brake valves of the individual wheels.

FIG. 3 is an alternative graph of FIG. FIG.
In the drive signal of the secondary system 2, the driving signal S of the driving signal S _p and the negative range of the positive range to be output from the primary system 1
It is already progressively supplied continuously from the set threshold value of _n . Complete control of the main actuator 6 (G2 _p or _G2 n)
Is reached, the drive signal is guided without reduction by multiplication by the value one.

A common one by at least two control systems
The two control variables, here the control of the dynamic dynamic control variable,
It can be done over a greatly extended range (eg all lateral acceleration levels). The sacrifices of control characteristics and the mutual interference of various control systems are eliminated. In addition, the use of wear control systems, for example, can be reduced (eg, wheel-by-wheel brake intervention to stabilize the vehicle).

[Brief description of the drawings]

FIG. 1 shows schematically the method according to the invention in the form of functional blocks.

FIG. 2 is a diagram showing a first method for realizing the functional blocks of the connection unit.

FIG. 3 is a diagram showing a second method for realizing the functional blocks of the connection unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st control system 2 2nd control system 3, 4 Connection unit 6 Main actuator 7 Auxiliary actuator _Sn , _Sp control threshold

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B62D 6/00 B62D 6/00 // B62D 137: 00

Claims (5)

[Claims] 1. A method for driving an actuator of a motor vehicle having at least two control systems for controlling a common control variable, wherein a first control system (1) as a primary system is associated therewith. The basic control is performed by driving the main actuator (6) thus set, and the second control system (2) as a secondary system depends on the drive signal to the main actuator (6). A method characterized in that it is connected to drive an auxiliary actuator (7) assigned to a secondary system (2). 2. The secondary system (2) outputs a drive signal assigned to an auxiliary actuator (7) independently of the primary system (1), and the drive signal of the secondary system (2) is 2. The method according to claim 1, wherein the auxiliary actuator is guided from a connection unit controlled by a drive signal to the auxiliary actuator. 3. The connection unit (3, 4) comprises a function block (3), which generates a value between 0 and 1 depending on a drive signal to a main actuator (6);
3. The method as claimed in claim 1, wherein the value is multiplied by the drive signal of the secondary system at a multiplication point. 4. A drive signal for a secondary system (2) is guided to an auxiliary actuator (7) when the main actuator (6) is completely driven. The method according to one. 5. The drive signal for the secondary system (2) is gradually guided to an auxiliary actuator (7) from a set control threshold value (S _n ; S _p ) of the main actuator (6). A method according to any one of claims 1 to 4.