DE102009011907A1 - Data processing system for stabilization of tractor trailer towed by passenger car, has determining device determining critical velocity of trailer based on detected vibrations, where critical velocity is perceptibly represented for driver - Google Patents

Abstract

The invention relates to a system for processing data for stabilizing a team, comprising a vehicle-drawn trailer. The system according to the invention comprises a device (1) for detecting trailer vibrations on the basis of the detection and evaluation of one or more measured variables (S,..., S), which represent driving dynamics characteristics of the vehicle and / or the trailer. Furthermore, the inventive method comprises a device (2) for damping the vibration of the team on the basis of driver-independent control actions on one or more, the vehicle dynamics influencing components (5) of the vehicle as a function of size (SG), which determines the intensity of a rolling movement of the team represents. There is further provided a device (3) for determining a critical speed (V) of the combination using one or more detected trailer oscillations, wherein the determined critical speed (V) for controlling the damping of the vibration is processable and / or in the vehicle for a Driver is noticeable presentable.

Description

The The invention relates to a system for processing data for stabilization a trailer that has a trailer towed by a vehicle. The system includes a device for detecting trailer vibrations the detection and evaluation of one or more measured variables, which represent vehicle dynamics properties of the vehicle and / or the trailer. The system further includes means for damping the vibration of the trailer based on driver-independent Control interventions on one or more, the vehicle dynamics influencing Components of the vehicle depending a size, which the intensity represents a rolling movement of the team.

The The invention further relates to a method for processing data to stabilize a team that is one of a vehicle drawn trailer having. In this method, trailer vibrations are based on the Acquisition and evaluation of one or more measurands, which represent the driving dynamics of the vehicle and / or the trailer, recognized. About that In addition, a vibration of the team and driver-independent control interventions to one or more, the vehicle dynamics influencing components of the vehicle depending on a Size, which the intensity represents the rolling movement of the team, muted.

at a vehicle combination can, z. B. due to crosswind, rolling movements occur at those of the followers swings about its vertical axis and over the hitch also the towing vehicle excites vibrations. Currently in use approaches to stabilize a team aiming at the team preferably decelerate rapidly below a so-called critical speed. Of the Value of the critical speed depends among other things on geometry data of the combination, such as wheelbase and drawbar length, of mass and yaw moment of inertia of the vehicle and the trailer as well as skew stiffnesses off the axles. It is typically in the area of passenger cars from 90 km / h to 130 km / h. The braking below the critical In principle, speed can already be achieved by the driver through an actuation of the driver Vehicle brakes are achieved.

automated Systems recognize, for example, critical tension oscillations Help of an implemented in the vehicle sensors and suitable Detection Algorithms in an ESP Controller (ESP = Electronic Stability Control) and initiate automatically a corresponding activation of the wheel brakes. Here are the Braking and the stabilization of the team by a symmetrical and asymmetric braking action on the wheels of an axle can be effected. To detect the rolling movement of the team, for example the amplitude curve of the yaw rate and the driver steering angle used.

At the Braking of the team occurs due to the temporary emergence of the trailer the towing vehicle usually first to a reinforcement the oscillation, since in overrun the critical driving speed, from which the pendulum amplitudes increase, is slightly smaller than in the Train operation or in free rolling driving condition. This results, that swiftly must be braked below the critical speed of the trailer, so that the vibration subsides. Especially at medium and low Road friction coefficients may be the sounding of the vibration too critical driving conditions and in the worst case lead to a buckling of the team. For example can especially critical driving conditions even when an untrained driver tries to get through Steering movements to stabilize the unstable team.

The critical speed of a team, d. H. the speed, from the the team constantly commutes, is due to driving in current vehicles the largely unknown and difficult to detect influencing parameters for pendulum sensitivity not specifically determined. This results for the device for damping the The disadvantage of that is to stabilize the team not taking advantage of their full Potentials can be made. In particular, there is a risk of incorrect operations.

It is therefore an object of the present invention, a system and a Method for processing data for stabilizing a team specify with which the driving safety of teams is increased can.

These Tasks are performed by a system with the characteristics of the patent claim 1 and a method having the features of claim 14 solved. advantageous Embodiments emerge from the dependent claims.

at a generic system for processing data to stabilize a team of As described above, according to the invention, a device for determining a critical speed of the team based on one or more detected trailer vibrations provided, wherein the determined critical speed for regulation the damping the vibration is processable and / or in the vehicle for one Driver is noticeable presentable.

at a generic method The above-described type according to the invention becomes a critical speed of the team based on one or more detected trailer vibrations determined, wherein the determined critical speed for regulation the damping the vibration is processed and / or in the vehicle for a Driver is perceived perceptible.

Of the Invention is based on the principle, the critical speed continuously approximate while driving to determine this then to control the damping the vibration to process and / or perceptible to the driver do. In particular, this gives the opportunity to inform the driver, how fast he can drive with the team. In addition, can the regulation of damping the oscillation of the team in a much more targeted manner, as this is possible in the prior art is. The critical speed puts you at a standstill the technique known a purely theoretical and often unknown size, which are undershot by appropriate control intervention must to keep the team stable.

The Invention looks in contrast before, the critical speed in the regulation of damping the Vibration of the team process and thus the type and / or intensity to influence the regulation. By including the critical Speed in a system for processing data for stabilization a team leaves Stability-critical Driving situations resulting from vibrations around the high axles of the team result, better counteract. With the invention can be corrective damping measures perform more targeted.

According to one Embodiment of the system according to the invention the vehicle dynamics influencing component is a braking system and / or a vehicle management and / or a steering system and / or a torque distribution system of the Vehicle. By the braking system z. B. a driver-independent symmetrical or asymmetric braking intervention are made, which in the correct phase position is performed to the stability-critical vibration. The vehicle management includes, for example, the reduction of Engine power or use of an electronic stability program used electronics to deliberately decelerate individual wheels or possibly to accelerate. Through the steering can be a temporary intervention done in the vehicle steering. This allows corrective To initiate steering movements or to avoid unfavorable steering movements. The procedure can be passive, d. H. without one intended by the driver Steering movement. It is also possible To complicate the driver incorrect steering movements or a steering recommendation to give to the hand, their compliance at the discretion of the driver is placed. Possible is also an active intervention in the steering in the sense of an actual Steering movement.

A Another embodiment provides that the device for determining the critical speed is adapted to the vibrations of the trailer to analyze the temporal course of the amplitudes. So may be provided in particular that the means for determining the critical speed is designed to a degree of damping for the Determine oscillation to get out of this the critical speed determine. The critical speed can be, for example, through the analysis of oscillations and on the basis of the oscillating Amplitude can be determined. This is done by means of vibration analysis found out from which degree of attenuation the amplitudes of the vibration increase or no longer decay. From this, the critical speed can be determined.

Especially is the device for determining the critical speed designed to be a stability criterion to determine that is a measure of the stability of the team represents. For this example, the Lehr'sche Dämpfungsmaß that a degree of damping represents to be determined. If the damping measure is smaller than zero, that is the case an unstable, under certain circumstances slippery, team. This means, when an oscillation excitation occurs, such as B. Crosswind, the stability of the team may not be made more. At a degree of attenuation of zero a quasi-stable team. This means that here is the critical Speed value. Is the degree of damping greater than zero, so is a stable or self-stabilizing team before, so that in this area no regulatory intervention makes sense are, even if through the device for detecting trailer vibrations a Oscillation of the team was detected.

According to one Another embodiment is the device for determining the critical Speed trained by means of a phase and / or Amplitude analysis a phase delay between a first and a establish second vehicle dynamics parameters of the vehicle and / or the trailer and to determine the critical speed from the phase delay. This phase delay can be achieved, for example, by cross-correlation determined between the first and second vehicle dynamics parameters become. The first driving dynamics parameter is, for example, a lateral acceleration, while the second vehicle dynamics parameter is a yaw rate, in particular the Vehicle, is.

A further preferred embodiment of the system according to the invention provides that activation of the device for damping the Vibration above the determined critical speed provided is. Conversely, this means that a regulation to dampen the Oscillation below the determined critical speed not or at least not mandatory, because due the knowledge of the critical speed on oneself Stabilizing team was detected. In particular, can be provided be that below a threshold speed, which is a given value is below the critical speed, none Regulation of damping done while between the threshold speed and the critical speed regulating in the damping is intervened.

According to one Another preferred embodiment is the device for damping the vibration designed such that the intensity of the damping in dependence the relation of the critical speed to a determined one (Actual) Speed value of the team is set. Due to the The system is capable of knowing the critical speed to recognize how fast and / or how aggressive a damping of Vibration must occur. In particular, a fast and aggressive damping then necessary if the team has a speed above the critical speed. If a damping of the Oscillation even at a speed value below the critical speed occurs, the measure of the damping dependent on of it, how close the actually driven speed of the team at the critical speed.

In a further embodiment are for perceptible presentation the critical speed of an optical and / or acoustic and / or provided a haptic output device. The critical speed can be indicated to the driver, for example, by a light or indicator in the Instrument cluster or in another display, eg. B. a human-machine interface (MMI), visually brought to the attention. Likewise, the achievement or crossing the critical speed in an acoustic way by a Sound or a sequence of tones which over the speakers of the vehicle are emitted, signaled. A haptic issue of reaching the critical speed for example, by shaking in the steering wheel, the vibration of a seat and the like realized become.

It is still appropriate if a memory for storing the critical speed for the control the damping the vibration of the team is provided. This requires the critical speed of the team only once determined to become, which then for the further processing for controlling the damping of the vibration of the team can be read from the memory. This adds to The above advantages also shorter reaction times of the device for damping the vibration allows since the time-consuming Calculation of the oscillation can be omitted.

Out establish the driving safety of the team, it is still appropriate if the system is designed to track the critical speed a terminal change and / or a detected state of the vehicle to redefine. This is advantageous because the critical Speed of a variety of factors, such as B. the moment of inertia the trailer, a vertical load, the type and mass of the load, the drawbar length and like that, depends. When a terminal change and / or a state of the vehicle is therefore assumed that at least one of the designated Changed parameters could have. Since this could affect the critical speed is Therefore, provided after each terminal change, z. B. stopping the Vehicle to re-determine the critical speed to the To maximize the potential of trailer stabilization.

Around the determination and determination of the critical speed too can be further provided that the originally determined value the critical speed as a starting point for the renewed Determination of the critical speed is processed.

The Invention will become more apparent below based on an embodiment explained. The single figure shows a schematic representation of a system for processing data to stabilize a team.

The data stabilization data processing system of the present invention comprising a trailer towed by a vehicle comprises means 1 for detecting trailer vibrations. Trailer vibrations are detected by detecting and evaluating one or more measured variables s ₁ ... S _n , which represent vehicle dynamics parameters of the vehicle and / or trailer. Such driving dynamics parameters may include, for example, a lateral acceleration of the vehicle and / or the trailer, a wheel speed of the vehicle and / or the trailer, a bending angle between the vehicle and the trailer, the buckling angle speed, a steering angle, a yaw rate of the vehicle and / or or the trailer.

The system further includes a device 2 for damping the vibration of the team on the basis of driver-independent control actions on one or more, the vehicle dynamics influencing components as a function of a control variable SG, which represents the intensity of the rolling movement of the team. The control quantity SG is calculated from the measured quantities s ₁ ... S _n by the device 1 determined. In the vehicle dynamics influencing components, which by the reference numeral 5 can be a braking system and / or a vehicle management and / or steering and / or a torque distribution system of the vehicle, which can be controlled in each case driver independently. In particular, the components influencing the vehicle dynamics include 5 such components that are already used to implement an electronic stability program (ESP) of the vehicle. The corresponding vehicle dynamics influencing components 5 received by the institution 2 for damping the oscillation of the team a corresponding control signal StS.

In addition, the system includes a facility 3 for determining a critical speed v _{crit of} the team using one or more detected trailer vibrations. For this purpose, the device receives 3 to determine the critical speed optionally one of the device 1 signal AS detected to detect trailer vibrations or directly one or more of the measured quantities s ₁ ... s _n . The determined critical velocity v _crit is processed to control the damping of the vibration and accordingly the device 2 fed. Alternatively or additionally, the critical velocity v _{crit may be} via an output device 4 of the vehicle are brought to the attention of the driver.

At the output device 4 it may be an optical and / or acoustic and / or haptic output device. The critical speed, for example, the driver by a light or display in the instrument cluster or in another display, eg. As a human-machine interface (MMI), visually brought to the knowledge. Likewise, the achievement or exceeding of the critical speed can be acoustically signaled by a sound or tone sequence emitted via the loudspeakers of the vehicle. A haptic output of reaching the critical speed can be realized, for example, by a shake in the steering wheel, the vibration of a seat and the like. Through the output device 4 the driver is able to recognize from which speed a critical situation for the team could occur.

In addition, the system may include a memory, not shown, in which the determined critical speed _value v _{crit is written} after its determination. This has the result that the critical speed value v _crit, at least between two clamping switch and / or stoppages of the vehicle, are only determined once and need for further processing by the means 2 or the dispenser 4 can be used. After a terminal change or a fixed state of the vehicle, it is expedient to determine the critical speed again. In these situations, it should be noted that, for example, the trailer could be detached from the vehicle (this can be determined by querying the assignment of the socket of the trailer hitch) or, for example, the load of the trailer has been changed. In contrast, it is not possible to load the trailer while driving or change its behavior, so that during a journey of the team a repeated determination of the critical speed v _{crit is} not necessary.

wobei gilt:

D:

Dämpfungsgrad,

d:

Dämpfungskonstante,

k:

Federkonstante,

m:

Masse,

ω₀:

Eigenkreisfrequenz.

A continuous, approximate determination of the critical speed v _crit during driving results in a better result, since the evaluation of as many pendulum oscillations is required for the purposeful determination of the critical speed v _crit . The determination of the critical speed can for example be done by analyzing the pendulum movements of the team. For this purpose, in particular a bending angle between the vehicle and the trailer, the buckling angle speed, optionally a steering angle of the vehicle and lateral acceleration of the vehicle to be considered. On the basis of the decaying amplitudes the Lehr's damping measure can be determined. The Lehr's damping measure (degree of damping D) is an energy quantity for the damping of a vibration. For a damped harmonic oscillation, the degree of damping D is defined as

where:

D:

Damping ratio,

d:

Damping constant,

k:

Spring constant,

m:

Dimensions,

ω ₀ :

Natural angular frequency.

Degree of damping D is unitless and describes the vibration behavior of a physical system. It is directly related to the so-called logarithmic decrement Λ via the equation:

wobei gilt:

x_m:

Amplitude des ersten Ausschlages,

x_n:

Amplitude des zweiten Ausschlages,

δ:

Dämpfungsgrad,

ω₀:

Eigenfrequenz der ungedämpften Schwingung,

T:

Schwingungsdauer.

The logarithmic decrement is a measure of the damping behavior in free-swinging, decaying vibration systems. It is calculated from the natural logarithm of the ratio of the amplitude of two successive deflections of the same direction:

where:

x _m :

Amplitude of the first excursion,

x _n:

Amplitude of the second excursion,

δ:

Damping ratio,

ω ₀ :

Natural frequency of the undamped oscillation,

T:

Oscillation period.

Alternatively, Λ can also be calculated as follows:

The Determination of the logarithmic decrement is by the practical Measuring the amplitude very easy to perform. It can then be the degree of damping determine.

At a damping degree D <0 is a lolling team, ie when a disturbance such. As side wind, it is assumed that an instability of the team, whereby a critical driving situation is expected. An attenuation D = 0 is a quasi-stable combination in which the amplitudes of the oscillations remain the same. This means that here the critical velocity v _{crit is} reached. On the other hand, with a degree of damping D> 0, there is a stable or self-stabilizing combination in which no intervention makes sense. It may be appropriate, as a limit for the implementation of the regulation of the damping of the oscillation not the critical velocity v _crit itself, but to use a slightly lower value, for. B. _Critical -10 km / h.

Alternatively, the critical speed can also be determined by a phase and / or amplitude analysis. In this case, a phase delay between two vehicle dynamics parameters of the vehicle and / or the trailer is produced, wherein from the phase delay then the critical speed v _crit can be determined. It is expedient to use the lateral acceleration and yaw rate, in particular of the vehicle, as the first and second driving dynamics parameters. The phase delay can be determined, for example, by cross-correlation of the two driving dynamics parameters.

The inventive system as well as the method according to the invention enable an improvement in the performance of trailer stabilizers and in particular a significant increase in robustness against incorrect interventions. Currently known trailer stabilizers determine the critical speed not or only relatively inaccurate and save this particular not off, so the critical speed is always new must be learned. In contrast, with the invention is a the actual Situation adapted control of the damping of the vibration possible. It more targeted interventions of the team stabilization are possible because the for the team critical point, namely the Reaching or exceeding the critical speed, is known.

in the The result will be an increase Traffic safety achieved, as well as the driver through the information on the critical speed is informed. This can be achieved by active intervention of the driver (ie reduction of speed) already at home to avoid a critical driving situation due to instability of the team.

One Another advantage of the invention is that the trailer stabilization on very simple and inexpensive Way to realize since the determination of the critical speed by a modification of software in the logic of trailer stabilization, on the ESP based, feasible. In addition, there are no additional hardware components necessary, which are subject to wear or cost.

1

Facility for detecting trailer vibrations

2

Facility for damping the vibration

3

Facility to determine the critical speed

4

output device

5

vehicle dynamics influencing component

s ₁

driving dynamics parameter

s _n

driving dynamics parameter

AS

signal

SG

Intensity of the rolling movement representing size

StS

control signal

v _crit

critical speed

Claims (13)

A system for processing data for stabilizing a trailer comprising a trailer towed by a vehicle, comprising: - means ( 1 ) for detecting trailer vibrations on the basis of the detection and evaluation of one or more measured variables (s ₁ ,..., s _n ), which represent the driving dynamics characteristics of the vehicle and / or the trailer, 2 ) for damping the vibration of the team on the basis of driver-independent control actions on one or more, the vehicle dynamics influencing components ( 5 ) of the vehicle as a function of a variable (SG), which represents the intensity of a rolling movement of the vehicle, characterized in that - a device ( 3 ) is provided for determining a critical speed (v _crit ) of the team using one or more detected trailer oscillations, wherein the determined critical speed (v _crit ) for controlling the damping of the vibration is processable and / or perceptible in the vehicle for a driver , System according to claim 1, characterized in that the vehicle dynamics influencing component ( 5 ) is a braking system and / or a vehicle management and / or a steering system and / or a torque distribution system of the vehicle. System according to claim 1 or 2, characterized in that the device ( 3 ) for determining the critical speed (v _crit ) is designed to analyze the oscillations of the trailer on the time course of the amplitudes out. System according to claim 3, characterized in that the device ( 3 ) for determining the critical speed (v _crit ) is designed to determine a degree of damping of the vibration in order to determine from this the critical velocity (v _crit ). System according to claim 3 or 4, characterized in that the device ( 3 ) for determining the critical speed (v _crit ) is designed to determine a stability criterion, which represents a measure of the stability of the team. System according to claim 1 or 2, characterized in that the means for determining the critical speed (v _crit ) is _adapted to, by means of a phase and / or amplitude analysis, a phase delay between a first and a second driving dynamics parameters (s ₁ , ... , s _n ) of the vehicle and / or the trailer and to determine the critical speed (v _crit ) from the phase delay. System according to claim 6, characterized in that the first driving dynamics parameter is a lateral acceleration and the second Vehicle dynamics parameters are a yaw rate, in particular of the vehicle. System according to one of the preceding claims, characterized in that activation of the device ( 2 ) is provided for damping the vibration above the determined critical velocity (v _crit ). System according to one of the preceding claims, characterized in that the device ( 2 ) is designed for damping the oscillation such that the intensity of the damping is set as a function of the relation of the critical speed (v _crit ) to a determined speed value of the vehicle. System according to one of the preceding claims, characterized in that for the perceptible representation of the critical speed (v _crit ) an optical and / or acoustic and / or haptic output device ( 4 ) is provided. System according to one of the preceding claims, characterized in that a memory for storing the critical speed (v _crit ) is provided for the regulation of the damping of the vibration of the team. System according to one of the preceding claims, characterized in that this is adapted to redetermine the critical speed (v _crit ) after a terminal change or a detected state of the vehicle. 13. System according to claim 12, characterized in that for the renewed determination of the critical speed (v _crit ), the originally determined value is processed as a starting point for the determination. A method of processing data to stabilize a trailer having a trailer towed by a vehicle, comprising: - detecting trailer vibrations based on the detection and evaluation of one or more measurements representing vehicle dynamics characteristics and / or the trailer; A vibration of the combination on the basis of driver-independent control actions on one or more vehicle dynamics influencing components of the vehicle depending on a variable, which represents the intensity of a rolling movement of the team, are damped characterized by the further step that A critical speed (v _crit ) of the combination is determined from one or more detected trailer vibrations, wherein the determined critical speed (v _crit ) for controlling the damping of the vibration is processed and / or displayed perceptibly in the vehicle for a driver.