Stabilization of a motor vehicle during emergency braking by alternating steering impulses

Abstract

The invention relates to a method for stabilizing a motor vehicle during emergency braking. For this purpose, direction-alternating micro-steering impulses are automatically superimposed on the steering system during the braking process, which cause a lateral micro-migration of the tire-road contact surface. The micro-steering impulses have an amplitude below that of the steering angle change consciously perceived by the driver and are designed to relieve thermally overloaded contact segments and cyclically engage adjacent, adhesive contact areas. This stabilizes the usable coefficient of friction on the tire contact patch. The procedure helps, particularly in dangerous situations during emergency braking on straight stretches or in curves, to compensate for a decrease in lateral grip and to maintain vehicle stability and steerability.

Description

[0001] The invention relates to vehicle safety technology, in particular systems for improving the stability and steerability of a motor vehicle during emergency braking. It applies to emergency braking on straight roads as well as in curves and provides a method for actively modulating the contact area between the tires and the road surface.

[0002] The present application is materially related to the application for the ZZBL principle filed on 17.12.2026 and claims its priority.

[0003] The steering excitation principles described therein form a technological background, while the present invention relates to an independent embodiment for the application case of emergency braking with contact surface-related friction coefficient modulation.

[0004] Within the scope of this description, the terms “micro-steering intervention”, “micro-impulse” and “steering impulse” are used synonymously insofar as they refer to the direction-changing steering impulses generated according to the invention in the sub-macroscopic range.

[0005] From DE 10 2024 001 244 A1 (D1) a method for improving traction on loose surfaces is known, in which sinusoidal steering oscillations are used to prevent getting stuck. However, D1 does not disclose either an emergency braking system or micro-steering impulses in the subgradient range during a braking process.

[0006] German patent DE 10 2005 019 339 A1 (D2) describes a system for off-road obstacles that performs steering oscillations at low speeds. The mechanisms described therein relate exclusively to starting and maneuvering situations and have no connection to dynamic emergency braking or thermally induced changes in the coefficient of friction.

[0007] DE 10 2015 224 760 A1 (D3) shows steering impulses for “rocking” a stuck vehicle free.

[0008] These impulses are used to initiate movement from a standstill and are not executed at high speeds or during emergency braking. No modulation of the tire contact patch to increase friction is disclosed.

[0009] DE 11 2020 004 314 T5 (D4) concerns a steering control logic for stabilization during wheel slip. D4 does not teach side-changing micro-impulses, thermal friction coefficient analysis, or a combination of steering impulses and braking operations.

[0010] German patent DE 11 2019 002 782 T5 (D5) describes an adaptive rear-wheel steering system for improving maneuverability. D5 does not relate to emergency braking or the regeneration of lateral grip forces through micro-movements of the tire contact patch.

[0011] None of documents D1 to D5 disclose micro-steering impulses with amplitudes below 2° and frequencies above the human reaction time for lateral contact patch movement during emergency braking. Likewise, they lack any instruction regarding thermal friction regeneration, an asymmetric impulse design for cornering, or coupling with friction monitoring systems.

[0012] The object of the invention is to provide a method that compensates for changes in tire contact patch conditions during emergency braking and increases vehicle stability independently of the steering angle, taking into account in particular thermal friction losses and the resulting losses in lateral grip.

[0013] During emergency braking, the human perception and reaction delay of typically 200-300 ms means that drivers regularly react too late to the onset of instability. The initial steering response is therefore disproportionately strong, resulting in abrupt oversteer.

[0014] The subsequent reflexive counter-steering is again delayed and with too high an amplitude, resulting in a pendulum-like sequence of over- and counter-steering movements, which often ends in a loss of lane keeping.

[0015] The delay arises primarily because the driver initially reacts to the visible vehicle position, while the actual driving dynamics causes – such as abrupt changes in lateral force requirements during combined braking and evasive maneuvers – begin earlier. Since the counter-reaction always occurs with a time lag, the instability intensifies cyclically until a macroscopic oscillation dynamic develops that can no longer be reliably controlled with human reaction patterns.

[0016] The micro-impulses according to the invention operate in the frequency range above human reaction time (typically > 2-3 Hz). This allows the necessary steering corrections to occur before the driver can perceive or react to the onset of instability. The system thus takes over the micro-reactions critical for vehicle safety, while the driver determines the macroscopic direction of travel.

[0017] The problem is solved by a method in which small, direction-alternating steering impulses are automatically applied to the steering system during emergency braking. These impulses cause a lateral micro-movement of the tire contact patch, thereby compensating for thermally induced losses in grip and regenerating the longitudinal and lateral forces required for vehicle stability.

[0018] The system uses vehicle dynamics measurements and sensor-based analyses to detect early indicators of an incipient decrease in friction coefficient. These include thermal changes, structural dynamic reactions of the tire, and deviations between expected and actual power transmission. The existing sensor technology includes vibration-based, thermal, structural-mechanical and walk-dynamic signal components. Direction-alternating steering impulses are understood to be small, oppositely directed changes in steering angle in the sub-degree range.

[0019] Depending on steering angle, yaw rate and tracking deviation, two operating modes are distinguished: - a symmetrical mode for stabilization during emergency braking in a nearly straight line, and - an asymmetric mode for regenerating lateral grip during emergency braking in curves.

[0020] Pulse time bias is defined as the ratio of pulse time components in the direction of the curve to pulse time components in the opposite direction. A bias of 60% means that at least 60% of the pulse duration occurs in the direction of the curve.

[0021] By automatically adjusting the impulse direction, intensity, and frequency, the system stabilizes the traction at the tire contact patch without requiring any additional action from the driver. The system works both preventively before ABS intervention and as a support during dynamic control phases.

[0022] The invention can enable more effective use of the existing coefficient of friction and thereby contribute to a reduction in the required braking distance in certain situations.

[0023] It maintains lateral stability and thus the vehicle's steerability even under high deceleration, especially on downhill curves and in evasive maneuvers.

[0024] The invention can be fully integrated into existing electronic control units and requires no additional mechanical hardware. Brief description of the characters

[0025] The invention is explained in more detail below with reference to schematic figures.

[0026] The drawings are not to scale and are only intended to provide a better understanding of the operating principle. Fig. Figure 1 schematically shows a motor vehicle during emergency braking on a straight stretch of road, in which direction-alternating micro-steering impulses according to the invention are applied to the steering system. The longitudinal direction of the vehicle and the lateral micro-migration of the tire contact patch in the millimeter range are shown. Fig. Figure 2 shows an enlarged section of the tire contact patch of a wheel. Thermally overloaded contact areas and adjacent, adhesive contact segments are shown, which are alternately introduced into the frictional area by the micro-displacements according to the invention. Fig. Figure 3 shows an example of the time course of the micro-steering impulses in symmetrical mode (mode A) for emergency braking on a straight stretch of road. The steering angle is plotted against time with small, oppositely directed deflections in the sub-degree range and a frequency in the range of a few Hertz. Fig. Figure 4 shows an example of the time course of the micro-steering impulses in asymmetric mode (mode B) for emergency braking while cornering. The figure depicts an impulse time bias in which a predominant part of the impulse duration occurs in the direction of the outer curve. Fig. Figure 5 schematically shows the resulting force distribution of a tire in a plotted friction diagram, represented as a friction ellipse (50). During activation of the micro-impulse method, a permissible release corridor (52) is opened within the friction ellipse, in which the resulting force vector (54) is guided by the micro-impulses. The angle ψ (56) describes the orientation of the resulting force vector relative to the longitudinal axis F. x (58). Point (62) represents the mixed friction value of the tire. Fig. Figure 6 shows a motor vehicle during emergency braking in a curve. The vehicle trajectory and a lane stabilized by the micro-steering impulses according to the invention, thus preventing lateral lane loss, are shown as examples. Fig. Figure 7 schematically shows the temporal progression of at least one measured variable derived from vehicle-internal sensor data, which is used to detect an incipient instability of the tire contact patch. An example threshold value is marked, above which the micro-steering impulses according to the invention are activated or switched from mode A to mode B. Mode A - Straight-ahead emergency braking

[0027] As in Fig. As shown schematically in Figure 1, the method according to the invention, during emergency braking on a straight stretch of road, operates by means of direction-alternating micro-steering impulses that cause a lateral micro-migration of the contact zone. During heavy deceleration and nearly straight driving, the system detects thermal overload, slip patterns unrelated to deceleration, or the beginning of lubricating film formation based on the evaluation of vehicle-internal sensor data. The temporal profile of the micro-impulses in symmetrical mode A is shown by way of example in Figure 1. Fig. 3 shown. Mode B - Cornering Emergency Braking

[0028] The transition between the two modes is in Fig. 5 is illustrated by a continuous adjustment of amplitude, frequency, and pulse time bias. An example pulse waveform of the asymmetric mode B with a predominantly pulse duration in the direction of the curve is shown in Fig. 4 shown.

[0029] At steering angles greater than 1.5°, the system detects understeer, drift tendency, or friction-related lateral force losses. The threshold of approximately 1.5° corresponds to a relevant limit for typical vehicles, above which a significant lateral force requirement arises.

[0030] Asymmetrical micro-steering impulses (0.5° - 2°, bias ≥ 60% in the direction of the curve) are generated, which regenerate the lateral force transmission and keep the vehicle stable in the curve.

[0031] If steering movements or road curvatures occur during emergency braking, the impulse mode is continuously interpolated between symmetrical and asymmetrical. Impulse amplitude, impulse frequency, and bias are continuously adjusted so that the transition between the two modes occurs without noticeable discontinuities.

[0032] The system is integrated into existing control units (ABS / ESC / EPAS) and requires no additional hardware.

[0033] The invention can be used in the following scenarios: - Emergency braking straight ahead - Emergency braking in curves - downhill sections - Evasive maneuvers, etc. Example 1 - Emergency braking on a straight stretch of road

[0034] To stabilize the vehicle, the system generates symmetrical micro-steering impulses (± 0.3° to ± 1.5°, typically 3-7 Hz), which laterally shift the contacting rubber zone and thereby increase effective static friction. This occurs before ABS intervention.

[0035] In a typical scenario, the vehicle is traveling at a speed of approximately 120 km / h on a straight stretch of highway when the driver suddenly detects an obstacle and performs an emergency stop with a deceleration of approximately 8 m / s². 2 initiates.

[0036] Within the first 50-100 ms after the rapid increase in brake pressure, the system detects an incipient drop in the coefficient of friction on at least one axle by evaluating vehicle-internal sensor data and wheel speed profiles.

[0037] In response, the system automatically generates a sequence of symmetrical micro-steering impulses with typical amplitudes in the range of 0.3° to 1.0°; depending on the vehicle class, the typical frequency is in the range of 4 to 6 Hz. The duration of such an impulse phase is preferably in the range of 300 to 800 ms.

[0038] During this phase, the effective contact zone of the tires shifts laterally several times by millimeters. The resulting micro-shifts relieve thermally overloaded contact areas and bring adjacent, adhesive segments into the friction zone.

[0039] Despite the micro-impulses in the longitudinal plane, the vehicle's trajectory remains virtually unchanged, so the driver perceives no change in direction. The continuous integration of these fresh contact segments significantly increases the usable coefficient of friction. The functionality of the contact surface change is described in Fig. 2 schematically illustrated. Example 2 - Emergency braking in a curve / motorway exit

[0040] Fig. Figure 6 shows an example of the stabilized vehicle trajectory during emergency braking in a curve.

[0041] In one embodiment, the vehicle is in a long downhill curve with a radius of curvature of approximately 200 m and a speed of 80 km / h when an obstacle becomes visible in the curve.

[0042] The driver suddenly presses the brake pedal and within a short time achieves a deceleration of approximately 6 to 7 m / s². 2 .

[0043] At this moment, the system detects a combination of increasing longitudinal wheel slip due to braking, decreasing lateral acceleration, and a deviation of the actual yaw rate from the target yaw rate expected based on steering angle and speed. From this, it is concluded that lateral grip is decreasing and understeer is imminent.

[0044] The system automatically switches to asymmetric mode and generates a pulse sequence with slightly increased amplitudes, approximately in the range of 0.7° to 1.8°, with the pulse time components in the direction of the curve being favored over those in the opposite direction. The effective bias in the direction of the curve can amount to 60 to 75% of the total pulse time.

[0045] The frequency of the micro-pulses remains at approximately 3 to 5 Hz, within a range that the tire structure can easily follow without causing undesirable macroscopic deviations in tracking.

[0046] This asymmetrical micro-pulse sequence increases the proportion of load-bearing contact segments on the outside of the curve, thus restoring lateral grip even under high longitudinal braking forces. The vehicle continues to follow the curve instead of drifting outwards towards the guardrail or obstacle. Example 3 - Downhill section / Truck

[0047] In the case of a heavy commercial vehicle with a permissible total mass of approximately 40 t, an emergency braking maneuver on a downhill slope of 6 - 8% can cause significantly higher thermal loads on the tires than in the case of a passenger car.

[0048] In a corresponding embodiment, the system detects, in addition to the high delay, a characteristic change in vibration-based sensor data, which indicates a soft, thermally fatigued running surface zone.

[0049] To prevent local overheating and the development of irreversible tread damage ("plates"), micro-steering impulses with a slightly reduced amplitude, for example in the range of 0.3° to 1.2°, and a frequency of approximately 3 to 4 Hz are used. The lower amplitude accounts for the higher vehicle mass and the greater moments of inertia of the truck, while the lateral movement of the contact patch is still sufficient to spatially distribute the thermal load.

[0050] Measurements can show that the surface temperature of individual tread segments remains noticeably lower with the impulse technology according to the invention than with a comparable emergency braking without micro-impulses, thereby improving both the stability and the service life of the tires.

[0051] Example 4 - Pendulum dynamics with delayed driver reaction In a specific embodiment, the critical phase begins as soon as the slip angle of the rear axle exceeds a certain threshold, for example in the range of 3° to 5°.

[0052] While a human driver only perceives this condition based on the visible vehicle movement and the noticeable lateral acceleration, the system detects even smaller deviations from the evaluation of the yaw rate, lateral acceleration and vehicle-internal sensor data.

[0053] Instead of executing large corrective movements with amplitudes typically ranging from 5° to 15°, as caused by human overreaction, the system generates a series of significantly smaller counter-impulses in the range of 0.5° to 1.5°. These are timed to counteract the development of the slip angle before any visible oscillation occurs. In the time it takes a driver to initiate a counter-steering movement after visually perceiving a lean, followed by an internal decision-making process and a muscular reaction, the system has already executed several complete micro-impulse cycles and dampened the development of the slip angle. This prevents the formation of large-amplitude oscillation dynamics and keeps the vehicle on the road. Example 5 - Transition situation (slight curve + emergency braking)

[0054] In another embodiment, the vehicle is on a gently curved country road with a radius of curvature of approximately 800 m. Due to a suddenly appearing animal, the driver initiates emergency braking and simultaneously performs a slight evasive maneuver, resulting in steering angles of approximately ± 2°.

[0055] Based on the steering angle profile, the system recognizes that there is no pronounced cornering, but a relevant lateral movement, and activates a transition mode in which the symmetry of the impulses is only slightly shifted in favor of the direction of evasion. The pulse frequency remains similar to that in straight-ahead mode, while the amplitudes are dynamically adjusted to the current steering angle. In this way, the contact patch modulation is maintained without altering the evasive trajectory specified by the driver. The driver's path correction and the system's microdynamic stabilization complement each other. Example 6 - Avoiding lane loss due to delayed driver reaction

[0056] In another example, a delayed evasive maneuver on a downhill curve leads to a pendulum-like instability of the vehicle. The method according to the invention prevents this dynamic by introducing direction-alternating micro-impulses in the early phase, which dampen both the initial oversteer and the subsequent pendulum movements. This prevents the slip angle from increasing uncontrollably and the vehicle from veering sideways off the road.

[0057] The vehicle remains controllable and follows the desired evasive trajectory. Variants and extensions

[0058] In a first variant, the impulse amplitude of the generated steering impulses can deviate from the values ​​mentioned in the exemplary embodiments.

[0059] In particular, amplitudes between ±0.1° and ±5° can be used, depending on the vehicle class, steering ratio, tire characteristics and permissible steering dynamics of the respective vehicle.

[0060] In another variant, the pulse frequency can lie within an extended range between 1 Hz and 12 Hz. The optimal frequency can be determined vehicle-specifically based on the natural frequencies of the body, wheel suspension, and front axle structure.

[0061] In an extended version, the steering impulses can be structured non-linearly.

[0062] For example, sharp-edged, exponentially increasing, step-shaped or adaptively modulated pulse shapes can be used, provided they cause an effective lateral displacement of the contact surface.

[0063] In another variant, the system can be activated based on dynamic thresholds that take into account brake pressure gradient, yaw rate profile, steering angle velocity, slip profile, or thermal signatures from sensor data. Activation can be achieved by combining multiple criteria using a logical AND / OR operator.

[0064] Alternatively, the activation process can be predictive, with a friction coefficient estimation model or an AI-supported friction coefficient predictor detecting impending loss of adhesion and initiating the pulse sequence before thermal or vibration-based indicators become visible.

[0065] In a further embodiment, the system can additionally take into account vehicle position data (GPS, camera, lidar) to determine curve radii or road geometry. This allows the pulse direction and intensity to be adjusted to upcoming curves in advance. A possible time course of such a measured variable with an activation threshold is shown in Fig. 7 shown.

[0066] In another variant, the impulses can also be influenced by external environmental data, such as rain, snow or wetness detection systems, ground detection data or road classification using camera systems.

[0067] In a further embodiment, the system can be coupled with ABS. Steering impulses are then only executed during the ABS relief phases in order to optimally utilize friction regeneration without interfering with ABS control.

[0068] Alternatively, the steering impulses can be made independently of the ABS intervention if the vehicle dynamics control detects, that a thermally advantageous contact surface modulation enables a more stable force transmission than brake pressure control alone.

[0069] In another variant, the system can interact with ESC / ESP. In this case, yaw moments generated by ESC can be used simultaneously to enhance the lateral force regeneration initiated by the steering inputs.

[0070] In a further embodiment, the system can synchronize the distribution of recuperation torques to individual axles with the steering impulses in electrically powered vehicles in order to optimally utilize the coefficient of friction.

[0071] In another variant, steering impulses in an electric steer-by-wire system can be executed completely without mechanical feedback to the steering wheel. Alternatively, with conventional EPAS steering, a small amount of feedback to the steering wheel can be permitted or selectively dampened.

[0072] In another embodiment, the pulse generator can dynamically derive its pulse direction from the evaluation of vehicle-internal sensor data, without relying on the driver's steering angle. This relieves the driver and maintains steering control despite minimal self-reactions.

[0073] In another variant, a temporary increase in the support moment in the steering actuator can be implemented to make the impulses more stable and precise, especially in the case of high lateral forces or vehicles with a high center of gravity.

[0074] In a further development, the contact surface modulation impulses can be combined with active chassis systems.

[0075] For example, an active lateral stabilizer or an adaptive shock absorber can generate tuned vertical impulses that positively influence the tire temperature distribution.

[0076] Alternatively, the system can be optimized exclusively for lateral guidance force.

[0077] In this case, a lower longitudinal deceleration is deliberately accepted during emergency braking in curves in order to maximize course stability.

[0078] In a further embodiment, the mode change between straight-ahead and cornering modes can be carried out continuously using a mixing parameter calculated from steering angle, yaw rate, curvature of the road and slip distribution.

[0079] In an extended version, the system can interact with the path planning system in autonomous vehicles and proactively initiate impulses to maintain the trajectories planned by the vehicle computer despite emergency braking.

[0080] In another embodiment, the system can use tire condition data from the manufacturer or AI-based tire models to individually adapt the thermal threshold detection to tire type, labeling class and degree of wear.

[0081] Finally, the system can be extended to additionally analyze the articulation angle dynamics when towing a trailer or using a multi-truck combination, and to adjust the steering inputs accordingly to prevent trailer sway or fishtailing. For this purpose, the articulation angle velocity between the towing vehicle and trailer can be used as an additional control parameter.

[0082] The direction-alternating micro-steering impulses according to the invention do not cause a macroscopic change in the direction of the vehicle, but rather a controlled lateral micro-movement of the tire contact patch relative to the road surface. Lateral micromigration refers to a shift in the effective contact zone in the range of a few tenths of a millimeter to a few millimeters. The physical mechanism of action on which the function according to the invention is based is described in detail below.

[0083] During emergency braking, flexing and slippage changes create locally high temperatures in the tire contact patch, which can lead to the formation of a thermally favored lubricating film.

[0084] The micro-impulses according to the invention generate short-term transverse forces which laterally displace the contact zone and relieve overheated segments.

[0085] This displaces the lubricating film and increases the proportion of adhering micro-serrations.

[0086] The coefficient of friction increases without the driver having to intervene.

[0087] The parameters of the micro-steering impulses - especially amplitude and frequency - are chosen so that the generated lateral accelerations remain within the range that is perceived as stable by the vehicle and do not cause any undesirable macroscopic deviations from the intended track.

[0088] The impulse frequency is preferably in a range that is significantly higher than the typical reaction time of a driver, but in a range in which the tire structure can react dynamically.

[0089] In cornering situations, the micro-impulses generated according to the invention are superimposed on the basic steering input specified by the driver or driver assistance system.

[0090] By designing the impulse sequence asymmetrically in the direction of the curve, the proportion of laterally supporting contact segments is increased, so that the available lateral guidance force is regenerated, even when high longitudinal braking forces are acting simultaneously.

[0091] This prevents the otherwise typical loss of lateral stability and the resulting tendency to drift straight ahead.

[0092] Overall, the invention is therefore not based on a change in the average braking force, but on a targeted manipulation of the local contact surface conditions at the tire contact patch over time. Driving stability and the usable coefficient of friction are improved by a high-resolution, lateral micromodulation of the contact zone.

[0093] In a conventional emergency braking maneuver, in addition to high longitudinal forces, significant thermal load peaks occur in the tire contact patch.

[0094] The rapid succession of adhesion and sliding phases during ABS regulation creates locally extreme temperature gradients. These can lead to irreversible thermal damage to the tread compound.

[0095] Experience has shown that this results in so-called "plates", i.e., flat structural detachments or melting of the running surface segment, which are formed by jerky slip changes.

[0096] Unlike normal wear and tear, such damage is irreparable and leads to a complete loss of the tire's functionality. The tire must be replaced immediately, even if there is no visible puncture or perforation.

[0097] The micro-pulse modulation according to the invention prevents the formation of these local extreme zones by shifting the contact surface laterally during the braking process.

[0098] This prevents the thermal energy from remaining permanently at one point on the running surface, but rather distributes it across adjacent segments. The peak thermal load is significantly reduced.

[0099] Additionally, the formation of a highly viscous lubricating film is suppressed, which can otherwise lead to sudden changes in adhesion / gliding and abrupt changes in slip. These sudden changes are a primary mechanism for sudden structural detachment on the running surface.

[0100] The impulse technology according to the invention not only improves driving stability but also reduces the risk of total tire failure, which can typically occur as a result of hard emergency braking maneuvers. This side effect represents a further safety advantage of the invention, particularly in the case of heavy vehicles or at high speeds.

[0101] ABS and ESC regulate only brake pressure and yaw moments, respectively. They do not affect the position, thermal or structural properties of the tire contact patch.

[0102] None of the systems generates lateral micro-movements, prevents the formation of thermal lubricant films, or regenerates lateral guiding force through contact surface modulation.

[0103] The function according to the invention does not work via torque or brake pressure, but via steering angle-based micro-impulses that generate a lateral micro-migration of the contact surface.

[0104] This relieves overheated segments, introduces fresh contact areas, displaces lubricant films and regenerates lateral guidance force even before ESC intervenes.

[0105] The micro-impulses act preventively, with a frequency above the human reaction threshold and within a range that maintains vehicle stability. ABS and ESC lack the structure and algorithm to enable such precise contact surface modulation. Conclusion:

[0106] The technology according to the invention is not a replacement for ABS / ESC, but a third system which operates on a completely different physical level: not about forces, but about contact surface conditions. Reference symbol list Vehicle and basic components 10 vehicles 11 Braking or reaction zone / contact area 12 Micropulse direction / Correction direction 14. Towing trajectory or unstable vehicle path ( Fig. 6) 14 Trigger point in the sensor signal ( Fig. 7) (Dual use is permitted, as it is context-dependent.) Axes and general signal quantities 16 Timeline 18 Steering angle or signal axis Steering angle signals and micro-impulses 20 Total pulse sequence / steering angle signal 22 dynamic zero position / upper signal guidance 24 positive micro-impulses 26 negative micro-pulses / counter-pulses / neutral range Friction ellipse and force transmission 50 friction ellipses 52 Release corridor / Activation window 54 resultant force vector 56 angles ψ 58 Longitudinal force axis (Fx) 60 Lateral force axis (Fy) QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2024 001 244 A1

[0005] DE 10 2005 019 339 A1

[0006] DE 10 2015 224 760 A1

[0007] DE 11 2020 004 314 T5

[0009] DE 11 2019 002 782 T5

[0010]

Claims

[1] Method for stabilizing a motor vehicle during an emergency braking maneuver, comprising generating direction-changing micro-steering interventions, including the micro-steering interventions - are superimposed on the driver's steering input and - cause a lateral micro-migration of the tire-road contact surface in the millimeter range, the micro-steering interventions are designed in such a way that - thermally overloaded micro-areas of the contact surface are relieved, - adjacent contact segments with higher friction potential are cyclically activated and - a usable coefficient of friction is increased, while maintaining the vehicle's steering ability during the emergency braking maneuver. [2] Method according to claim 1, wherein the steering impulses have an amplitude in the range of 0.1° to 2.0°. [3] Method according to claim 1 or 2, wherein the pulses are generated with a frequency between 2 Hz and 7 Hz. [4] Method according to one of the preceding claims, wherein the steering impulses cause a lateral micro-migration of the tire contact patch in the range of 0.1 mm to 5 mm. [5] Method according to any one of the preceding claims, where the impulses are activated, when a deterioration in the coefficient of friction is detected based on vehicle dynamics measurements. [6] Method according to any one of the preceding claims, where a symmetrical micropulse mode is used, when an emergency braking maneuver occurs during an almost straight driving path. [7] Method according to any one of the preceding claims, in which an asymmetric micro-pulse mode is activated, when an emergency stop occurs while cornering. [8] Method according to claim 7, where there is a pulse time bias of at least 60% is generated in the direction of the outer curve. [9] Method according to any one of the preceding claims, in which a transition mode is executed, which continuously interpolates between symmetric and asymmetric pulse modes. [10] A method according to any of the preceding claims, wherein the impulse parameters are adjusted depending on vehicle speed, steering angle, yaw rate, or lateral acceleration. Dependent claims - physical mechanisms / sensors [11] Method according to any one of the preceding claims, where a sensor device is used, to thermally induced structural changes or to detect local temperature gradients at the tire contact patch. [12] Method according to one of the preceding claims, wherein an incipient loss of adhesion is predictively determined on the basis of structural dynamic reactions of the tire. [13] Method according to any one of the preceding claims, where the micro-impulses serve to to break up or displace a thermally favored lubricating film on the tire surface. [14] Method according to one of the preceding claims, wherein the micro-pulses reduce the local thermal peak load of the running surface. [15] Method according to any one of the preceding claims, where the impulses are used, to prevent the formation of irreversible tread damage (“plates”). [16] Method according to one of the preceding claims, wherein the micro-pulses are activated prior to the ABS control process. [17] Method according to any of the preceding claims, wherein the micro-pulses act in parallel to ESC control processes without impairing the ESC function. [18] Method according to any one of the preceding claims, where the impulses are deactivated, as soon as ABS or ESC detect an unstable condition, which requires immediate braking or yaw moment control. [19] Method according to any one of the preceding claims, in which a safe basic operating mode ("fail-safe mode") is activated when faulty sensor data is detected. Subclaims - special use cases [20] Method according to one of the preceding claims, wherein the pulse amplitude for heavy vehicles (trucks, buses) is automatically reduced and the frequency is adjusted. [21] Method according to one of the preceding claims, wherein the micro-pulses are adapted taking into account the articulation angle velocity between the towing vehicle and the trailer. [22] Method according to one of the preceding claims, wherein the transition mode takes into account the curve curvature and the change in steering angle over time. [23] Method according to any one of the preceding claims, in which the impulse algorithm continuously The slip angle development of the rear axle is monitored. Subclaims AI / learning algorithms [24] Method according to any one of the preceding claims, where an AI model is used, to take into account long-term changes in tire condition. [25] Method according to one of the preceding claims, wherein the impulse logic learns from previous braking operations and adaptively improves the parameters of the micro-impulses. [26] System for carrying out the method according to any of the preceding claims, comprising a steering system a sensor device for recording vehicle dynamic, thermal or structural dynamic parameters, a computing unit and an actuator for generating micro-steering impulses. [27] System according to claim 26, wherein the actuator is a steer-by-wire system or an electrically assisted steering system. [28] System according to claim 26 or 27, wherein the computing unit is implemented programmatically and is coupled to ABS or ESC via a communication interface. [29] Computer or electronic control unit configured to carry out a method according to any one of claims 1 to 25.

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