Method and device for steering a vehicle

Abstract

Method (300) for steering a vehicle (100) which, due to a collision, has damage to the vehicle axle or to a component connected to the vehicle axle, so that, depending on the severity of the collision, one or more wheels of an axle are no longer fully steerable or can no longer be steered at all, the method (300) comprising the following steps: - reading (305) a detection signal (135) representing a detected damage to a vehicle axle (106) of the vehicle (100); and - Providing (310) a steering signal (140) using the detection signal (135), wherein the steering signal (140) represents a change in the orientation of a first wheel (110) associated with a further vehicle axle (116) of the vehicle (100), and providing a braking signal (145) to a braking unit (150) of the vehicle (100) connected to the further vehicle axle (116) in order to at least partially brake a second wheel (115) associated with the further vehicle axle (116) of the vehicle (100), so that the vehicle (100) is steered into a safe area, in particular a roadway wheel, after the collision in order to avoid further damage or even injuries to a passenger of the vehicle.

Description

[0001] The present invention relates to a method and a device for steering a vehicle.

[0002] DE 10 2015 225 800 A1 describes a method for influencing a vehicle movement.

[0003] Against this background, the present invention provides an improved method and an improved device for steering a vehicle according to the main claims. Advantageous embodiments emerge from the subclaims and the following description.

[0004] One object of the invention is to be able to move a vehicle, if possible, to a safe area outside the accident zone after a collision resulting from an accident and resulting damage to a vehicle axle, which may result in a loss of the transferable wheel contact forces on the corresponding axle. This can, for example, prevent further injury to a vehicle occupant or further damage.

[0005] A method for steering a vehicle is presented, the method comprising a reading step and a providing step. In the reading step, a detection signal is read in, which represents detected damage to a vehicle axle of the vehicle. In the providing step, a steering signal is provided using the detection signal, wherein the steering signal represents a change in alignment of a first wheel associated with another vehicle axle of the vehicle. Furthermore, in the providing step, a braking signal is provided to a braking unit of the vehicle connected to the other vehicle axle in order to at least partially brake a second wheel associated with the other vehicle axle of the vehicle.

[0006] The method can preferably be carried out in a vehicle that is designed to transport people and, additionally or alternatively, objects. Such a vehicle can, for example, be realized as a passenger car. The detection signal can, for example, comprise image data or values ​​or parameters that represent the damage to the vehicle axle or to a component connected to the vehicle axle, such as vehicle wheels. The damage can, for example, have been caused by a collision of the vehicle with another vehicle or an object. Due to an accident, the damage can, depending on the severity of the accident or collision, mean that one or more wheels on an axle are no longer fully steerable or even no longer steerable at all. The alignment change refers to a changed wheelbase or wheel position or wheel alignment, e.g.Changed steering angle of the vehicle's wheel, which is referred to here, for example, as the first wheel. Advantageously, this allows the vehicle to be steered to a safe area, such as the shoulder of the road, after a collision and additionally or alternatively braked to prevent further damage or even injury to a vehicle occupant.

[0007] According to one embodiment, in the reading step, the detection signal can be read in via an interface to a sensor device, wherein the sensor device can preferably be designed as a steering sensor, a wheel suspension sensor, and additionally or alternatively as an acceleration sensor. The steering sensor can detect, for example, a change in the wheel steering angle and / or a change in the direction of the vehicle. Advantageously, damage can be detected by the sensor device. The steering sensor can be arranged, for example, on a steering actuator. The wheel suspension sensor can be arranged in a wheel suspension of the vehicle, e.g., on a control arm of the chassis, and the acceleration sensor can be arranged, for example, on a control unit, such as the airbag control unit.

[0008] According to one embodiment, the steering signal can be output in the providing step in order to control cornering by means of a steering movement, during which the first wheel can be on the outside of a curve radius and additionally or alternatively the second wheel can be on a curve radius. Advantageously, cornering is controlled after a collision, for example in order to move the vehicle from one lane to a safe edge zone. Advantageously, the vehicle remains steerable even after the collision. This can, for example, prevent traffic congestion. Subsequent collisions can also be avoided if necessary, since the vehicle does not form an obstacle on the road.

[0009] According to one embodiment, in the providing step, the steering signal can be output to the first wheel of the additional vehicle axle, which is configured as a rear axle of the vehicle. Advantageously, the rear axle of the vehicle can thereby assume a steering function and a braking function of the vehicle in order to keep the vehicle as steerable as possible even after damage to the first steerable axle.

[0010] Alternatively, according to a further embodiment, in the providing step, the steering signal can be output to the first wheel of the additional vehicle axle, which is configured as a front axle of the vehicle. Advantageously, the front axle of the vehicle can thereby assume a steering function and a braking function of the vehicle, for example, if a steerable rear axle fails due to damage.

[0011] According to a further embodiment, the detection signal can be read in during the reading step if it has been detected that at least one wheel of the vehicle axle is not steerable. After a serious accident or collision, for example, the corresponding vehicle wheels or the vehicle axle are damaged to such an extent that steering is not possible. This means that even after serious damage, the other vehicle axle advantageously takes over steering until the vehicle is safely brought out of the respective danger zone, for example, to the side of the road, in particular to a standstill.

[0012] The method may further comprise a step of deactivating a steering movement in the same direction from wheels of the vehicle axle to wheels of another vehicle axle, for example, as is common at high vehicle speeds to stabilize handling, and additionally or alternatively, the first wheel and additionally or alternatively the second wheel of the other vehicle axle. This can advantageously prevent further damage to the vehicle.

[0013] According to one embodiment, in the providing step, the steering signal can further cause a change in the orientation of the second wheel. Additionally or alternatively, the braking signal can also trigger braking of the first wheel. This can advantageously amplify the steering movement.

[0014] According to one embodiment, in the providing step, the steering signal can be provided with knowledge of an obstacle in front of the vehicle, in order to avoid the obstacle by aligning the first wheel and additionally or alternatively the second wheel. The obstacle can be, for example, an object with which the vehicle has collided or, for example, another road user. The obstacle can be detected, for example, using lidar, radar, or a camera in the vehicle. Advantageously, the vehicle can avoid an obstacle in a controlled manner and come to a safe stop.

[0015] Furthermore, according to one embodiment, the method can, in response to the braking signal, include a step of locking the first wheel if the second wheel was braked, or of locking the second wheel if the first wheel was braked. This is particularly useful if the steering system used on the axle in question is a central actuator that can steer both wheels in the same direction.

[0016] Another advantageous embodiment of the approach presented here is one in which, during the locking step when the vehicle is cornering, an inside wheel is locked as the second wheel. Advantageously, the inside wheel is briefly locked, for example, for a period of 0.5 s to 1 s. By locking the inside wheel, no or only reduced steering forces are transmitted, which might not lead to the intended vehicle movement. Instead, locking the wheel generates a turning yaw moment acting on the vehicle. The approach presented here further provides a device designed to perform, control, or implement the steps of a variant of a method presented here in corresponding devices. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved cost-effectively and efficiently.

[0017] A device can be an electrical device that processes electrical signals, for example sensor signals, and outputs control signals depending on them. This is preferably a control unit that is arranged in the vehicle and is itself divided into units that are designed, for example, to control a braking signal. The device can have one or more suitable interfaces that can be designed in hardware and / or software. In a hardware design, the interfaces can, for example, be part of an integrated circuit in which functions of the device are implemented. The interfaces can also be separate integrated circuits or consist at least partially of discrete components. In a software design, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

[0018] Also advantageous is a computer program product with program code that can be stored on a machine-readable medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the embodiments described above when the program is executed on a computer or device.

[0019] The invention is explained in more detail by way of example with reference to the accompanying drawings. They show: Fig. 1 a schematic representation of a vehicle to explain an embodiment of the approach presented here; Fig. 2 a schematic representation of a vehicle to explain an embodiment of the approach presented here; and Fig. 3 a flowchart of an embodiment of a method for steering a vehicle.

[0020] In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0021] Fig. 1 shows a schematic representation of a vehicle 100 to explain an embodiment of the approach presented here. The vehicle 100 shown here is designed, for example, as a passenger car. According to this embodiment, two wheels 105 of the vehicle 100 are damaged, which according to this embodiment are implemented as front wheels and are accordingly arranged on a vehicle axle 106 shown here. The vehicle 100 further has a first wheel 110 and a second wheel 115, which are arranged on a further vehicle axle 116, also shown here. According to this embodiment, the first wheel 110 and the second wheel 115 are implemented as rear wheels of a rear axle. This means that according to this embodiment, the further vehicle axle 116 is implemented as a rear axle.According to an alternative embodiment, the further vehicle axle 116 can be implemented as the front axle 106 of the vehicle 100, analogously to the variant shown here.

[0022] According to this exemplary embodiment, the vehicle 100 has a device 120 that is designed to control or carry out a method for steering a vehicle 100. The device 120 has a read-in unit 125 and a provision unit 130 for this purpose. According to this exemplary embodiment, the read-in unit 125 is designed to read in a detection signal 135 that represents detected damage to the vehicle axle 106 of the vehicle 100. The provision unit 130 is designed to provide a steering signal 140 using the detection signal 135, wherein the steering signal 140 represents a change in the alignment of the first wheel 110 associated with the other vehicle axle of the vehicle 100.According to this exemplary embodiment, the provision unit 130 is designed to provide a braking signal 145 to a braking unit 150 of the vehicle 100 connected to the further vehicle axle 116 in order to at least partially brake the second wheel 115 associated with the further vehicle axle 116 of the vehicle 100. Optionally, the device 120 reads the detection signal 135 if, according to this exemplary embodiment, it has been detected that the vehicle axle is not steerable. According to this exemplary embodiment, the device 120 reads the detection signal 135 via an interface to a sensor device 157, which is designed, for example, as a steering sensor, a wheel suspension sensor, and / or an acceleration sensor.According to this exemplary embodiment, the device 120 provides the steering signal 140 in order to control cornering by means of a steering movement, in which the first wheel 110 is located on the outside of a curve radius and / or the second wheel 115 is located on the inside of a curve radius. According to this exemplary embodiment, the device 120 is further configured to execute a steering movement in the same direction of the wheels 105 of the vehicle axle 106 and / or the first wheel 110 and / or the second wheel 115 of the further vehicle axle 116.

[0023] According to this exemplary embodiment, a steering direction 155 of the first wheel 110 is implemented to achieve a curve direction 160. For this purpose, the first wheel 110 is oriented obliquely to a longitudinal axis 170 of the vehicle 100 and points to the left, towards the outside of the curve. According to this exemplary embodiment, the curve direction 160 to the right illustrates that the vehicle 100 is moving clockwise due to a yaw moment. The yaw moment is caused by the steering angle at the first wheel 110. According to this exemplary embodiment, the second wheel 115 is oriented parallel to the longitudinal axis 170 and brakes the vehicle, for example by applying a braking force 175 that counteracts a vehicle force. This amplifies the yaw moment, so that the vehicle as a whole is steered to the right in a curve direction.

[0024] According to this exemplary embodiment, the provision unit 130 is further configured to provide the steering signal 140 with knowledge of an obstacle in front of the vehicle 100, in order to avoid the obstacle by aligning the first wheel 110 and / or the second wheel 115. An obstacle is detected, for example, by at least one optical sensor 180 or several optical sensors 180, which are arranged, for example, at the front and / or rear of the vehicle 100. This allows both the size and type as well as the speed of the obstacle to be determined.

[0025] Fig. Figure 2 shows a schematic representation of a vehicle 100 to explain an embodiment of the approach presented here. The vehicle 100 shown here corresponds to the Fig. 1 described vehicle 100. Only the alignment of the second wheel 115 of the other vehicle axle is different to Fig. 1. Such an alignment of the second wheel 115 can be realized, for example, by designing the corresponding steering system as a central actuator 200, which steers both wheels 110 and 115 in the same direction, so that the second wheel 115 has the same alignment as the first wheel 110. The first wheel 110 and the second wheel 115 are thus aligned in the same direction to one another. This means that, according to this exemplary embodiment, the device 120 (not shown here) also causes a change in the alignment of the second wheel 115. Additionally or alternatively, braking of the first wheel 110 can be controlled.

[0026] According to this embodiment, this so-called central actuator steering 200 behaves analogously to the Fig. 1, whereby the second wheel 115 can be caused to lock (at least briefly) for the desired steering operation in order to prevent any steering forces from being transmitted to this wheel. With a steering movement in the same direction on the left and right rear wheels 110, 115, no or insufficient yaw moment can be generated in the event of an accident due to the lack of or insufficient support of the yaw moment on the front vehicle axle 106. Therefore, it is advisable to completely brake the inside wheel of the curve, i.e., in this case, the second wheel 115, until it locks, preferably when the wheels 105 on the front vehicle axle 106 are no longer able to transmit the corresponding wheel contact forces.

[0027] Optionally, the first wheel 110 can be locked when the second wheel 115 has been braked or alternatively the second wheel 115 can be locked when the first wheel 110 has been braked.

[0028] In other words, in the event of a moderately severe accident, for example a frontal impact on the front side of vehicle 100, steering on the front axle, which according to this exemplary embodiment is referred to as vehicle axle 106, is usually no longer possible because parts of the wheel suspension and / or the wheels 105 are correspondingly damaged. Such a moderately severe frontal impact can be understood, for example, as an accident involving vehicle 100 in which only one wheel 105 of the relevant vehicle axle 106, here the front axle, is no longer steerable. Steering on the rear axle, referred to as an additional vehicle axle 116, may no longer be possible if a moderately severe rear impact has occurred, which prevents steering on the rear axle. In this case, it is sufficient that only one wheel of the rear axle is no longer steerable for this moderately severe rear impact.Furthermore, a severe accident on the front or rear axle of the vehicle can lead to a loss of the transferable wheel contact forces on the corresponding axle, which may make it impossible to generate or control a vehicle yaw moment. Such a severe accident can be understood, for example, as the wheels of the affected axle no longer being steerable at all. The approach presented here solves this problem through an advantageous combination of a braking and steering action on a functional axle or individual wheels of an axle. Through the clever use of mechatronic chassis actuators, the steering capability of the vehicle 100 is maintained to the greatest extent possible after a collision.

[0029] For example, if a moderately severe accident is detected in the front area of ​​vehicle 100, the additional vehicle axle 116 with its rear-axle steering can be used to continue steering vehicle 100, for example, to avoid obstacles or drive to the side of the road. According to this exemplary embodiment, damage to the front axle is detected by the sensors in the steering actuator, by sensors or a sensor device 157 in the wheel suspension, or centrally by acceleration sensors, such as those present in an airbag control unit.

[0030] According to this exemplary embodiment, when damage to a vehicle 106 is detected, it is expedient, particularly in vehicles 100 that, for example, have autonomous vehicle control capabilities, to take control of the vehicle 100. If, for example, steering movements are performed, it may be expedient not to transmit these movements to a steering wheel of the vehicle 100, or only to transmit them in a greatly reduced form, in order to avoid any further injury to a driver or passenger of the vehicle 100.

[0031] The following describes only an implementation for an accident involving the front axle (FA). In the event of an accident involving the rear axle (RA), the solutions explained below apply analogously to the application of the corresponding interventions on the front axle. In particular, a combination of steering at one vehicle wheel and braking of another vehicle wheel on the axle not affected by the accident is advantageous for generating a vehicle yaw moment.

[0032] In the event of a serious accident involving vehicle 100, e.g., when the vehicle collides with an obstacle at high speed, a one-sided or complete loss of steerability occurs at the vehicle axle 106, for example, and possibly a significant loss of the transmissible lateral forces or tire contact forces by the wheels 105, which are also referred to as front axle tires or wheels. For this reason, it is advantageous to deactivate the steering movement of a steering system of the other vehicle axle 116 in the same direction as the vehicle axle at high vehicle speeds, since this may no longer result in steering movements that correspond to the driver's intention or a desired course of the vehicle 100.A steering movement of the first wheel 110 and / or the second wheel 115 on the further vehicle axle 116 in the same direction as the vehicle axle may lead to an opposite or uncontrolled steering movement due to the lack of transferable tire contact forces on the vehicle axle and the resulting lack of torque support about the vehicle vertical axis / yaw axis, which can be avoided by the approach presented here.

[0033] According to this exemplary embodiment, the steering of the vehicle 100 is taken over exclusively by the steering of the additional vehicle axle 116, here the rear axle with rear-axle steering, in order to enable, for example, wheel-individual steering. Since sufficient lateral forces can no longer be transmitted by the wheels 105 on the damaged vehicle axle, a yaw moment initiated by a steering movement on the additional vehicle axle cannot, for example, be adequately supported there. Therefore, in this case, it is particularly expedient to steer and / or at least partially brake only one wheel on the rear axle, such as the first wheel 110, and to brake exclusively the second wheel 115. As a result, according to this exemplary embodiment, it is still possible to generate a yaw moment 175 about the vehicle's vertical axis.According to this exemplary embodiment, the steering movement is also stronger due to the combination of steering at the first wheel 110 and braking at the second wheel 115 than would be possible with sole braking action on just one wheel. For example, if the vehicle 100 is to be steered to the right, the right rear wheel, which corresponds to the second wheel 115 in this exemplary embodiment, could be braked and the left rear wheel, referred to here as the first wheel 110, could be steered to a negative toe angle toward the outside of the curve, thus generating a corresponding rightward yaw moment 175 on the vehicle 100.

[0034] According to an alternative embodiment, the vehicle 100 has an additional chassis actuator system for changing the tire contact force between the vehicle axle and the other vehicle axle, or between the individual wheels 105, 110, 115, such as a wheel-selective air suspension or, for example, electronically adjustable or controllable pitch stabilizers. According to one embodiment, it is expedient to reduce the tire contact force on the vehicle axle 106, 116 affected by the collision or on the damaged wheels 105, 110, 115 and thus increase the tire contact force on the functional, steerable wheels 105, 110, 115, for example, to ensure maximum possible maneuverability of the vehicle 100.

[0035] Fig. 3 shows a flowchart of an embodiment of a method 300 for steering a vehicle. The method 500 can be carried out in a vehicle as described in one of the Fig. 1 or Fig. 2. The method 300 comprises a step 305 of reading in and a step 310 of providing. In step 305 of reading in, a detection signal is read in which indicates a detected damage to a vehicle axle (as described, for example, in the Fig. 1 or the Fig. 2 with the reference numeral 106) of the vehicle. In step 310 of providing, a steering signal is provided using the detection signal, wherein the steering signal represents a change in the orientation of a first wheel 110 assigned to another vehicle axle 116 of the vehicle according to the Fig. 1 or Fig. 2. Furthermore, in step 310 of providing, a brake signal is provided to a brake unit of the vehicle connected to the further vehicle axle in order to apply a brake signal to the further vehicle axle 116 in accordance with the Fig. 1 or Fig. 2 of the vehicle. According to this exemplary embodiment, the method 300 further comprises a step 315 of deactivating a steering movement in the same direction of wheels of the vehicle axle and / or the first wheel and / or the second wheel of the further vehicle axle when a vehicle speed is greater than a threshold value of, for example, 50 km / h. Furthermore, the method 300 comprises a step 320 of locking based on the brake signal of the first wheel if the second wheel was braked, or of the second wheel if the first wheel was braked.

[0036] The exemplary embodiments described and shown in the figures are selected only as examples. Different exemplary embodiments can be combined with each other in their entirety or with regard to individual features. Furthermore, one exemplary embodiment can be supplemented by features of another exemplary embodiment.

[0037] Furthermore, method steps according to the invention can be repeated and carried out in a different order than that described.

[0038] If an embodiment comprises an “and / or” link between a first feature and a second feature, this can be read such that the embodiment according to one embodiment has both the first feature and the second feature and according to another embodiment has either only the first feature or only the second feature. Reference symbol 100 vehicles 105 wheels 106 vehicle axle 110 first wheel 115 second wheel 116 vehicle axle 120 device 125 reading unit 130 Provisioning Unit 135 detection signal 140 steering signal 145 Brake signal 150 brake unit 155 Steering direction 157 Sensor device 160 Curve direction 170 Longitudinal axis 175 Yaw moment 180 optical sensors (camera, lidar, radar) 200 central actuator, central actuator steering 300 procedures 305 Step of reading 310 Step of Deployment 315 Deactivation step 320 Step of Blocking

Claims

[1] Method (300) for steering a vehicle (100) which, due to a collision, has damage to the vehicle axle or to a component connected to the vehicle axle, so that, depending on the severity of the collision, one or more wheels of an axle are no longer fully steerable or can no longer be steered at all, the method (300) comprising the following steps: - reading (305) a detection signal (135) representing a detected damage to a vehicle axle (106) of the vehicle (100); and - Providing (310) a steering signal (140) using the detection signal (135), wherein the steering signal (140) represents a change in the orientation of a first wheel (110) associated with a further vehicle axle (116) of the vehicle (100), and providing a braking signal (145) to a braking unit (150) of the vehicle (100) connected to the further vehicle axle (116) in order to at least partially brake a second wheel (115) associated with the further vehicle axle (116) of the vehicle (100), so that the vehicle (100) is steered into a safe area, in particular a roadway wheel, after the collision in order to avoid further damage or even injuries to a passenger of the vehicle. [2] Method (300) according to claim 1, wherein in the step (310) of providing the steering signal (140) is output in order to control cornering by a steering movement in which the first wheel (110) is on the outside of a curve radius and / or the second wheel (115) is on the inside of a curve radius. [3] Method (300) according to one of the preceding claims, wherein in the step (305) of reading in, the detection signal (135) is read in via an interface to a sensor device (157), wherein in particular the sensor device (157) is designed as a steering sensor, a wheel suspension sensor and / or as an acceleration sensor. [4] Method (300) according to one of the preceding claims, wherein in the step (310) of providing, the steering signal (140) is output to the first wheel (110) of the further vehicle axle (116), which is designed as a rear axle of the vehicle (100). [5] Method (300) according to one of claims 1 to 3, wherein in the step (310) of providing, the steering signal (140) is output to the first wheel (110) of the further vehicle axle (116), which is designed as a front axle of the vehicle (100). [6] Method (300) according to one of the preceding claims, wherein in the step (305) of reading in, the detection signal (135) is read in if it has been detected that at least one wheel (105) of the vehicle axle (106) is not steerable. [7] Method (300) according to one of the preceding claims, comprising a step (315) of deactivating a steering movement in the same direction from wheels (105) of the vehicle axle (106) to wheels (110, 115) of the further vehicle axle (116) and / or the first wheel (110) and / or the second wheel (115) of the further vehicle axle (116). [8] Method (300) according to one of the preceding claims, wherein in the step (310) of providing the steering signal (140) a change in the orientation of the second wheel (115) is further effected and / or wherein the braking signal (145) controls braking of the first wheel (110), in particular when braking power on a wheel (110) on the outside of the curve is reduced. [9] Method (300) according to one of the preceding claims, wherein in the step (310) of providing, the steering signal (140) is provided in knowledge of an obstacle in front of the vehicle (100) in order to cause the obstacle to be avoided by aligning the first wheel (110) and / or braking the second wheel (115). [10] Method (300) according to one of the preceding claims, comprising a step (520) of blocking the second wheel (115) in response to the brake signal (145), in particular when the vehicle (100) is steered on the further vehicle axle (116) via a central actuator (200) and / or a steering effect exclusively on the first wheel (110) is desired. [11] Method (300) according to claim 10, wherein in the step (320) of blocking when cornering the vehicle (100), a wheel on the inside of the curve is blocked as the second wheel (115). [12] Device (120) which is arranged to carry out and / or control the steps (305, 310, 315, 320) of the method (500) according to one of the preceding claims 1 to 10 in corresponding units (125, 130). [13] Computer program product which is configured to execute and / or control the steps (305, 310, 315, 320) of the method (300) according to one of claims 1 to 11. [14] A machine-readable storage medium on which the computer program product according to claim 13 is stored.

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