DE19700567A1 - Device for stabilising of vehicle - Google Patents

Abstract

The device comprises a shock absorber (FE) and an adjusting member at each wheel (VR1,2,HR1,2) of vehicle (FZ). The adjusting member is arranged between the vehicle body (K) and the suspension. A restoring force (R) is produced by the adjusting member for each wheel for compensating the internal and/or external disturbing forces of the vehicle. The restoring force is active between each wheel and the vehicle body. Through the effect of the adjusting members, the vehicle body is brought from an unstable balance into a neutral balance or may be held in the neutral balance.

Description

It is known that vehicle stability is considered according to body stability and driving stability. Body stability can be viewed in terms of the longitudinal direction (rocking stability), the transverse direction (rolling stability) and height direction (lifting movement).

Fig. 6 vehicle or body movements and their designation.

It is known that the same for vehicle dynamics weight problem is of decisive importance and in the highest Measures the stability of the vehicle.

It is known that price stability is at risk if the Effect from increased influence of the mass distribution of a vehicle occurs.

It is known that in the pursuit of active safety - by one maximum retention of course stability and controllability achieve - a regulatory system is required that is difficult in Unstable balance situations (unstable balance The center of gravity does not fall or return to its old position back) ensures maximum price stability, and an indifferent Establishes equilibrium (indifferent equilibrium = insensitive compared to the disturbance).

It is known that in the moving vehicle with coil suspension the rulesy acting in the ongoing feedback action dynamic equilibrium restoration system most as counter forces the counter-spring of the coil spring / damping and the built-in vehicle stiffness.

However, it is necessary to endure body deflection with passive action of the coil spring control system with a lack of system efficiency.

Fig. 8a, inefficiency of the coil suspension, drawing of the rolling moment without AVAS and photo DB S class in cornering.

The invention specified in claim 1 is the pro underlying any coil suspension system in the dy dynamic vehicle stability generate and optimize.

This problem is solved by those mentioned in claim 1 Features (by the action between body and screws spring with AVAS hydraulic control system that is complete in itself is made and that is the imbalance of dynamic Vehicle instability in its particular dynamic Brings back and maintains balance), solved.

The advantages achieved with the invention are in particular in that instead of dynamic vehicle instability through the coil suspension and chassis design compromise dynamic vehicle stability is effectively created by the passive coil suspension control system an action force F is added by AVAS. AVAS advantageously complements each Coil suspension vehicle without neither body nor chassis To change the new design, it only requires assembly of the control system. Can therefore be used for any coil suspension and thus a radical improvement of the conventional screw suspension. AVAS as an active dynamic control system be leaves each coil suspension / damping in its function or he leaves stiffness reduction and additionally equips the screws Suspension / damping with the property of the active body sta balancing and any level regulation.

The advantages achieved with the invention also consist in that AVAS creates unrivaled active safety and comfort because dynamic vehicle stability is created in full function the coil spring base with the least effort, because AVAS supports the coil suspension and only creates the missing one Differential force in the counter spring power to the maxima len vehicle stability; in the event of a system failure, the driving is Unrestricted use of tools, on the other hand, the same system runs case in the hydraulic suspension suspension system to considerable Restrictions on vehicle use, and compared to a futuri fiction, or future solution (in the form of a full  active suspension system, with extreme energy requirements, with laser radiation scanning of the road, microprocessor control of the Hy draulic, so that the construction of the wheels over the uneven road ten lifts) with the advantage that with full chassis system failure, only the emergency use of the vehicle remains. AVAS with coil suspension is a universal control system.

The advantageous embodiment of the invention is in the patent pronounced 1. The training according to claim 2 he enables AVAS, each for a specific positioning and execution of the main hydraulic cylinder and coil spring to be able to assemble further construction.

An embodiment of the invention is shown in the drawings and is described in more detail below.

Show it:

Fig. 1 main drawing for AVAS action,

Fig. 2 drawing of the main hydraulic cylinder around the Schrau benfeder,

Fig. 3 drawing of the main hydraulic cylinder around spring and damper,

Fig. 4 AVAS in the front wheel suspension DB 190 screws,

Fig. 5 AVAS in the rear DB 190 screws suspension,

Fig. 6 Body movements

Fig. 7a drawing of Wippmoments without AVAS,

Fig. 7b drawing of Wippmoments with AVAS,

Fig. 8a drawing of the roll moment without AVAS and photo DB S class during cornering,

Fig. 8b drawing of roll moment with AVAS and photo DB S class during cornering,

FIG. 9a drawing of the leveling without AVAS,

Fig. 9b drawing of the level control with AVAS,

FIG. 10a Load-dependent Karosserieeinfederung without AVAS,

Fig. 10b-dependent load leveling by AVAS,

Fig. 11a cornering / Karosserieeinfederung without AVAS and photo DB S Class,

Fig. 11b cornering with AVAS and photo DB S Class,

FIG. 12a Karosserieeinfederung during braking without AVAS,

Fig. 12b Karosserieeinfederung when braking with AVAS,

Fig. 13 AVAS overview,

Fig. 14a / 14b AVAS in the BMW 7 series.

There follows the explanation of the invention with reference to the drawings according to the structure and also according to the mode of operation of the presented inven dung.

The moving vehicle is subject to constant changes in load. These movements and forces (suspension forces and damping forces) occur in numerous sizes, directions and levels.  

Body movements that are kept indifferently balanced by AVAS.

Fig. 6, body movements.

Driving vehicle with coil suspension can then be considered as a complex vibration system. For maintaining stability of the vehicle tries a control system. This control system ar operates at a feedback speed.

For maximum dynamic vehicle stability generation Coil suspension vehicle it is necessary an indifferent Generate and maintain balance by the control system the necessary differential restoring forces are added.

Vehicle stability is considered body stability and driving stability. Body stability is divided into:

• a) rocking stability - longitudinal direction,
• b) roll stability - transverse direction,
• c) Height stability - stroke direction.

Fig. 7a, drawing of the rocking moment without AVAS. The rocking moment is absorbed by the springs.

Fig. 7b, drawing of the rocking moment with AVAS. The rocking moment is absorbed by the springs and AVAS also ensures an indifferent body balance.

Fig. 8a, drawing of the rolling moment without AVAS. The rolling moment (turning in the suspension) is absorbed by springs.

Fig. 8b, drawing of the rolling moment with AVAS. The rolling moment (turning in the suspension) is absorbed by springs and AVAS also ensures an indifferent body balance.

Fig. 9a, drawing of the level control without AVAS. Load-dependent lifting movements, rising and falling are absorbed by the springs.

Fig. 9b, drawing of the level control with AVAS. Load-dependent lifting movements, rising and falling are absorbed by the springs and AVAS also ensures an indifferent body balance.

The operation of the invention is the addition of the restoring forces to the body stability system. The rolling moment, the rocking moment, the lifting movement cause reaction forces in the suspension. The counteracting moment of the springs is adequately supplemented with differential restoring forces to counteract each individual reaction force from the body deflections.

Fig. 1, main drawing of the AVAS mode of operation. The microprocessor processes information from sensors, compares it with stored limit values and controls the valves. AVAS also ensures an indifferent body balance.

Cornering

Fig. 1a, cornering / body deflection without AVAS and photo DB S class. When driving through a curve, in cross winds or on a road with an incline, the rolling motion of the body, i.e. different wheel loads, occurs. A strong shift in weight towards one wheel of the axle causes counter-suspension.

Fig. 11b, cornering with AVAS and photo DB S class. AVAS compensates for the body deflection. The valves are controlled analogously. AVAS ensures an indifferent body balance. AVAS creates roll stability, rocking stability and height stability.

Brakes and accelerations

Fig. 12a, body deflection when braking without AVAS. When braking or accelerating, the rocking movement, the rolling movement or the lifting movement of the body, i.e. different wheel loads, occur. A strong shift of weight towards a wheel of the axle or from axle to axle causes counter-springing.

Fig. 12b, body deflection when braking with AVAS. When braking or accelerating, the body deflection is compensated by AVAS against rocking, rolling or lifting. AVAS creates rocking stability, rolling stability and height stability. AVAS increases driving stability with extreme driving styles.

Load-dependent adjustment - level regulation

Fig. 10a, load-dependent body deflection without AVAS. The load deflects the bodywork, i.e. under different wheel loads. A strong shift of weight towards a wheel of the axle or from axle to axle causes counter-springing.

Fig. 10b, load-dependent level regulation by AVAS. Body deflection created under load is compensated by AVAS, while analog driving is constantly regulated. AVAS creates height stability, rocking stability and roll stability.

Active four-wheel anti-rebound-diagonal body stabilization level differential correction control system (AVAS) is an active, dynamic, body-indifferent balance control system, stabilizing, changing, asymmetrical and diagonal deflection, and also level-regulating with symmetrical loads, thus under static loads it creates with AVAS double-acting hydraulic piston, ie:
active because the additional restoring force F is generated by AVAS, i.e. it is not only dependent on springs and dampers and can be varied as required,
dynamic because while driving,
indifferent balance because insensitive to the disturbance,
Control system because a feedback system,
double-acting hydraulic ring piston, because the pressure above and below the ring piston is controlled so that the body remains at the desired height,
Stabilizing, alternating compression, because the shortening of the spring on one side of the axle and extension on the other side are compensated for by double-acting hydraulic ring pistons from the AVAS,
Stabilizing asymmetrical and diagonal compression, because the shortening of the spring on one front axle side and lengthening on the diagonal other side of the rear axle (when cornering) is compensated for by double-acting hydraulic ring pistons from the AVAS,
Level-regulating with symmetrical compression, because the lifting movement of the body under load is compensated by double-acting hydraulic ring pistons of the AVAS.

The AVAS versions around coil spring and spring / damper:

Fig. 2, drawing of the main hydraulic cylinder of the AVAS around coil spring.

Fig. 3, drawing of the main hydraulic cylinder of the AVAS around the spring / damper.

The AVAS as an example - attachment in DB 190:

Fig. 4, AVAS in the front wheel DB 190 coil suspension.

Fig. 5, AVAS in the rear wheel DB 190 coil suspension.

The AVAS as an example - construction in the BMW 7 Series:

Fig. 14a, BMW 7 series rear wheel spring damper unit with AVAS.

Fig. 14b, BMW 7 Series Mac Pherson strut with AVAS.

Reference list

AVAS consists of:

1

Double-acting hydraulic cylinders for each screw benfeder (

Fig.

2), or coil spring / damper (

Fig.

3)

2nd

High pressure hydraulics (up to 10 MPa) with pressure control, Oil pump and lines (

Fig.

13)

3rd

Control valves with switching frequency up to 100 Hertz (

Fig.

13)

4th

Sensors (

Fig.

13): Accelerometers

4th

a spring deflection sensor of each coil spring, gas valve potentio meters as a height sensor, working analogously, for Coil spring deflection every spring or body deflection height, provides measurement signals to the microprocesses sor (

Fig.

2 and

Fig.

3)

4th

b Steering angle sensor for measuring the steering angle optoelectronic sensor, delivers measurement signals to the Microprocessor (

Fig.

13)

4th

c Brake pressure switch sensor of the deceleration signal of the Braking process, delivers measurement signal to the microprocessor (

Fig.

13)

4th

d Speed sensor delivers measurement signal to the micro processor (

Fig.

13)

4th

e Yaw rate sensor, delivers measurement signal to the Microprocessor (

Fig.

13)

4th

f Lateral acceleration sensor, delivers measurement signal to the Microprocessor (

Fig.

13)

5

Microprocessor, for the processing of the sensors delivered signals, for the calculation of the required Values from these signals, for comparing the calculated values with the saved values and for the Determine the appropriate setting of the construction height, ge suitable adjustment of the control valves to the hydraulics cylinders (

Fig.

13). Microprocessor with self-diagnosis system and fault memory.

6

Hydraulic oil tank (

Fig.

13)

7

Hydraulic oil accumulator (

Fig.

13)

Claims (2)

1. Active four-wheel anti-suspension diagonal body stabilization level difference correction control system (AVAS) with predetermined effect for dynamic vehicle stability and active safety generation, characterized in that any vehicle coil suspension is unmistakably provided with the hydraulic system AVAS, acting between the body and above the coil spring plate is made for itself and which brings the imbalance of the dynamic vehicle instability back into its specific dynamic equilibrium and maintains despite the effects of internal disturbance (driver) and external disturbance (curve, unevenness, gust of wind, acceleration, braking, loading).
Fig. 2 coil spring with AVAS. 2. AVAS according to claim 1, characterized in that any vehicle coil suspension with strut unequally complementary - with hydraulic system AVAS verse is hen, acting between the body and upper bearing of a spring leg, which is made for itself and the imbalance of dynamic Brings vehicle instability back into its respective dynamic balance and maintains it despite internal and external interference.
Fig. 3 shock absorber with AVAS.