Method and Apparatus that takes in consideration the driver steering reaction for a tractor-trailer combination

State of the art

The invention relates to a method and apparatus for stabilizing a road vehicle according to DE 199 64 048 A1.

In DE 199 64 048 A1 is a road vehicle, in particular a passenger car with a drawn through the passenger car trailers, monitored in terms of rolling motions. Upon detection of a rolling movement of the vehicle, a yaw moment is automatically imprinted, which is in phase opposition to the snaking movement substantially.

From DE 100 31 266 A1 a method and a device for detecting an oscillating movement of a vehicle are known. For this purpose, the device includes at least a first detection means by which a lateral dynamics of the vehicle representing lateral dynamics variable is determined. It also contains second determination means by which one describing the vehicle speed speed variable is determined. With the help of the third detection means is determined as a function of the transverse dynamics quantity and the speed variable, whether a pendulum motion of the vehicle is present. A pendulum motion occurs, when the speed variable is greater than an associated threshold value, and when the lateral dynamics variable is greater than an associated threshold value.

The features of the preambles of the independent claims are taken from the DE 199 64 048 A1.

ADVANTAGES OF THE INVENTION

The invention relates to a device for damping the rolling motions of a trailer towed by a road vehicle,<ul><li>which rolling motion detection means by which a rolling movement of the trailer and its intensity is detected on the basis of size, in which at least one enters the vehicle lateral dynamics variable describing and</li><li>Roll damping means by which takes place the damping of the snaking movement based driver-independent braking of the road vehicle and / or driver-independent reduction in engine torque at an intensity threshold is exceeded by the intensity of the rolling movement,</li></ul>contains. The core of the invention is characterized in that further <ul><li>Steering angle analysis means are available with which from the time variation of the steering angle at least one parameter is determined and</li><li>the intensity threshold which, if exceeded by the intensity of the rolling movement of the damping of the rolling motion occurs, depends on the determined characteristic variable.</li></ul>Since the steering angle profile represents the driver's request, it is thus possible to adjust the roll damping on the previous driver behavior. In size, in which at least one enters the vehicle lateral dynamics variable describing, it can be in particular a combined size, in which both the vehicle transverse dynamics variable describing as well as a driver's desired size is received.

Further, the steering angle analysis means are designed so that at least the basis of the so determined characteristic variable between<ul><li>a present panic steering reaction of the driver and</li><li>a consciously performed by the driver maneuver</li></ul>A distinction is made and<ul><li>is the intensity threshold depending on whether a panic steering reaction of the driver or deliberately by run by the driver maneuver exists.</li></ul>Particularly in a carried out as consciously recognized maneuvers to the experienced drivers the possibility, to stabilize the combination of own driving skills ( "fun").

An advantageous embodiment of the invention is characterized in that a present panic steering reaction of the driver is detected when the determined characteristic value exceeds a threshold parameters.

An advantageous embodiment of the invention is characterized in that the parameters threshold of the vehicle longitudinal speed is dependent. This makes it possible that in the low speeds the driving skill a wide space will be given, while at high speeds rather a driver-independent stabilization intervention is to train.

An advantageous embodiment of the invention is characterized in that is only recognized to present panic steering reaction of the driver, when the intensity of the rolling movement grows additional time or there is an oscillation with increasing amplitude.

The growth of the snaking intensity is an indication that the driver the trailer stabilization fails under its own power.

An advantageous embodiment of the invention is characterized in that in the case of the driver of a detected panic steering reaction, a smaller intensity threshold is chosen as in the case of a deliberately performed by the driver detected driving maneuver. This ensures that when the driver panic behavior a rapid stabilization intervention occurs.

An advantageous embodiment of the invention is characterized in that a low-pass filter is provided through which the parameter is filtered prior to further processing. This high-frequency interference are filtered out.

An advantageous embodiment of the invention is characterized in that<ul><li>a steering angle analysis only then takes place if at least the change in steering angle per unit time exceeds a predetermined limit value, and</li><li>for the case that no steering angle analysis takes place, the intensity limiting value is set to a predetermined default value.</li></ul>The steering angle analysis consumes computing time in the control unit (for example, in the control unit of the driving dynamics controller). Therefore it is advantageous to the steering angle analysis be carried out only when evidence of a substantial steering reaction of the driver are present.

An advantageous embodiment of the invention is characterized in that a steering angle analysis only takes place if, in addition, the intensity of the rolling movement exceeds a predeterminable limit value. Also be avoided unnecessary steering angle analysis.

An advantageous embodiment of the invention is characterized in that the intensity of the rolling movement is determined by the difference between the low-pass filtered actual yaw rate of the road vehicle and the target yaw rate.

An advantageous embodiment of the invention is characterized in that the target yaw rate is determined based on a single-track model. This is mathematically simple and therefore easy to implement programmatically.

The invention includes a method for damping the rolling motions of a trailer of a road vehicle-drawn, in which<ul><li>a rolling movement of the trailer and its intensity is detected on the basis of size, in which at least one enters the vehicle lateral dynamics variable describing and</li><li>at an intensity threshold is exceeded the damping of the snaking movement is performed by the intensity of the rolling movement based driver-independent braking of the road vehicle and / or driver-independent reduction in engine torque,</li></ul>contains, characterized in that<ul><li>from the time variation of the steering angle of at least one characteristic variable is determined and</li><li>the intensity threshold which, if exceeded by the intensity of the rolling movement of the damping of the rolling motion occurs, depends on the determined characteristic variable.</li></ul>

Here, at least based on the so determined characteristic variable between<ul><li>a present panic steering reaction of the driver and</li><li>a consciously performed by the driver maneuver</li></ul>distinguished and<ul><li>the intensity threshold is dependent on whether a panic steering reaction of the driver or deliberately by run by the driver maneuver exists.</li></ul>

The advantageous embodiments of the inventive device express themselves naturally also as advantageous embodiments of the inventive method and vice versa.

drawing

The drawing consists of the figures 1 and 2. FIG.

In Fig. 1, the structure of the overall system is illustrated.

In FIG. 2, the analysis of the steering angle is shown.

embodiment

With a vehicle combination can, for example, occur due to side wind, swaying movements, where the trailer swings around its vertical axis and stimulates via the trailer coupling and the tow vehicle to vibrate. If the vehicle speed vFz<ul><li>below the so-called critical speed vFzkrit (vFz &lt;vFzkrit), then the vibrations are damped,</li><li>at vFz = vFzkrit undamped and</li><li>above the critical speed (vFz&gt; vFzkrit) sound to the vibrations, ie the amplitude or intensity increases.</li></ul>The value of the critical velocity vFzkrit mainly depends on geometry information such as wheelbase and drawbar length, mass and yaw moment of inertia of the vehicle and the trailer and on the lateral tire stiffness of the axes. It is car-trailer combinations typically in the range 90-130 km / h. For recognition of the rolling movement of the vehicle combination, the difference between the treated (in particular low-pass filtered) yaw rate VGIF and from the driver input (steering angle, vehicle longitudinal speed) formed target yaw rate vGiSoAck used. In addition, the steering angle in the release of stabilizing interventions is taken into account so as not to sensitively intervene in targeted driver's steering movements. Therefore, the driver's steering movements are analyzed to early release the trailer stabilization in panic steering response, thus contributing to increased safety. The driver is analyzed due to the driver's steering movements and variables derived therefrom and evaluated. Depending on the stabilization interventions are released. This makes it possible to identify the driver of a hand panicked behavior in time and release necessary stabilization interventions appropriate to the situation, on the other hand as well as possible to adapt the triggering of antivibration interventions on specific driving maneuvers. This contributes to the process for increased safety and increased comfort when driving with trailers.

The analysis of the steering angular motions will be explained with reference to FIG. 2.

In block 201 the driver's steering movements are terms<ul><li>the steering angle Lw,</li><li>of the steering angle change (per unit time) as well as</li><li>the duration of the steering movements</li></ul>analyzed. This one parameter KoLw is formed. This parameter is filtered in block 202 with a low-pass filtered and derived the characteristic KoLwF.

With the filtered size KoLwF and optional additional parameters will be held to recognize different situations in the blocks 203 and 204th In Fig. 2 this example, only two blocks (203 and 204) are located, it may be, of course, but also to act just a block or more than two blocks, as indicated by the dots ( "...") in the vertical direction indicated between blocks 203 and 204th

In block 203 a panic steering movement and the driver's steering response is detected based on the size KoLwF. In this case, an attenuation of the trailer fishtailing by driver-independent brake intervention is essential. A panicked driver's steering response is recognized that the size exceeds a KoLwF (optional dependent on the vehicle longitudinal velocity) threshold. In addition to this threshold crossing other conditions such as a yaw rate threshold or increasing amplitudes of the trailer oscillation can be used.

The described analysis of the steering angle curve further driving situations can be for example detected overtaking another motorist with easy fishtailing trailer and adapted the triggering threshold of the snaking logic and thus the engagement release based on this information in order to prevent unnecessary intervention in addition to the panic detection.

In block 204, the existence of an overtaking maneuver is detected. For example, shears the vehicle on a multi-lane roadway to the left and then to the right again. In this case, driver-independent braking interventions are undesirable (as long as the intensity of the trailer fishtailing course does not exceed a predetermined threshold).

In another (not shown) block, for example, be recognized that the driver already counteracts automatically and expertly by skillful steering maneuver the trailer swing. In this case, it is also dispensed with driver-independent braking interventions.

The outputs of blocks 203 and 204 (and optionally further blocks) are forwarded to block 205, in which the driver-independent intervention in the brake system (wheel-specific braking interventions) and / or the engine control (reduction in engine torque) are carried out.

The blocks 203 and 204 are provided for detecting the situation besides the size KoLwF course other sizes (for example, the vehicle longitudinal speed vFz or the low-pass filtered yaw rate VGIF).

The analysis of the steering angle curve in block 201 takes place only when on input 206 of block 201 results in an enable the analysis. For instance, can be considered the Lenkwinkelgradient. In order to quick end to the panic to avoid detection in itself reassuring steering angle history, one of the triggering threshold of different limit (and possibly other conditions as a second yaw rate threshold) for the demolition of the steering angle analysis and reset the panic detection is used.

Embedding the apparatus in a larger system shown in Fig. 2 is shown in FIG. 1. This is at block 103 to the system shown in Fig. 2.

In Block 100, the difference between the actual yaw rate VGIF and the target yaw rate vGiSoAck is formed in FIG. 1. The target yaw rate is vGiSoAck is thereby formed in block 102 from the input variables Lw (= steering angle and steering wheel angle) and vFz (= longitudinal vehicle speed). Based on the time course of the size VGIF - vGiSoAck is determined in block 101, whether a rolling movement of the trailer (which is transferred to a rolling movement of the vehicle) is present. The difference is size VGIF - vGiSoAck examined periodically in time or almost periodically recurring structures. May be performed on the so-called wavelet. As an alternative to a wavelet transform to the use of a Fourier transform is possible in principle, but its computational implementation has the disadvantage higher memory requirements on (at a wavelet are very high data compression rates achievable).

The output from block 101 is forwarded to block 103rd There (and optionally other additional signals) is decided on the release of driver-independent measures for trailer stabilization based on the steering angle. In particular, a reduction in engine torque (exit 104) or wheel-specific braking interventions is (starting 105) intended.