Steering assistance in the event of steering servo failure

Abstract

A method for providing power steering assistance in a vehicle (100), wherein the vehicle (100) further comprises a steering servo system and a motor coupled thereto, characterized in that a steering servo failure is detected due to a fault in the steering servo system and / or an engine stop, and the following is carried out upon the steering servo failure: - determining (201) an intention of a driver of the vehicle (100) on the basis of at least one sensor (131) which at least partially receives vehicle-internal information I intern catches up; - determining (202) a current driving situation of the vehicle (100) on the basis of at least one sensor (132) which at least partially receives vehicle-external information I extern , whereby the determination of the current driving situation is based on a current vehicle speed v act is based; - determining (203) on the basis of the determined intention of the driver and the determined existing traffic situation whether there is a need for power steering assistance, wherein the need for power steering assistance increases with an increase in the current driving speed v act decreases; and - providing (204) the power steering assistance when it is determined that the need exists.

Description

Technical area

[0001] The present invention relates to a method for providing power steering assistance in a vehicle according to the preamble to patent claim 1. The present invention also relates to a system arranged in a vehicle for providing power steering assistance according to the preamble to patent claim 14, a vehicle comprising the system, and a computer program and a computer program product which implement the method according to the invention. background

[0002] The following background description constitutes the description of the background for the present invention, but does not necessarily represent the prior art.

[0003] Modern vehicles often use a steering servo system to facilitate steering, i.e., to turn at least the front wheels. A steering servo system on a vehicle therefore means that less force is required to turn the steering wheel when turning the vehicle's wheels. Hydraulic steering servo systems, electro-hydraulic steering servo systems, and electric steering servo systems are available.

[0004] Without power steering systems, vehicles are very difficult to maneuver, especially at low speeds. In heavy vehicles such as trucks, buses, or similar vehicles, it is virtually impossible for the driver to turn the steering wheel if the power steering system is not activated or is defective.

[0005] In the event of a steering servo failure, i.e., when the steering servo system no longer provides power steering, the vehicle becomes very difficult to maneuver. Such a steering servo failure can occur, for example, if the vehicle's engine stops, since the steering servo pump in a hydraulic steering servo system is often coupled to and driven by the engine. Such a steering servo failure can also occur if one or more faults are present in a vehicle's hydraulic and / or electrical steering servo system.

[0006] Such power steering failures can be a direct threat to traffic if they occur while driving, and can be extremely irritating for a driver if they occur, for example, while parked or during a short trip. A previously presented solution to reduce these risks and irritation involved installing two hydraulic power steering systems—a primary system and a secondary system—in a vehicle. According to this solution, a complete secondary backup system was engaged and / or utilized when the primary system no longer provided power steering.

[0007] From DE 10 2010 010 856 A1 a method for automatically assisting a driver of a motor vehicle is known, wherein a lateral guidance and longitudinal guidance intervention is carried out which can be overridden by the driver.

[0008] DE 603 15 766 T2 discloses a method for providing an emergency steering control, wherein in the event of a failure of a steer-by-wire system, a directional control of a vehicle generates a yaw moment on the vehicle by selectively braking individual wheels of the vehicle.

[0009] Furthermore, DE 689 02 857 T2 discloses a control circuit for an electric power steering system which comprises a torque sensor for detecting a steering torque.

[0010] Furthermore, DE 10 2004 006 835 A1 shows a steering system with a hydraulic servo motor, which is permanently supported by an electric servo motor

[0011] DE 10 2012 218 155 A1 discloses a device for preparing an input for a driver of a vehicle on a touch-sensitive display. Furthermore, DE 10 2014 204 671 A1 discloses a monitoring system for determining a change in the physical condition of a vehicle occupant. Brief description of the invention

[0012] However, one problem with the prior art solution using two hydraulic steering servo systems is that equipping vehicles with two hydraulic steering servo systems is very expensive, significantly increasing the vehicle's manufacturing cost. Another problem with this solution is that neither the primary nor the secondary system can provide power steering if the steering servo is driven by the engine and a steering servo failure occurs due to an engine shutdown.

[0013] The object of the present invention is therefore to provide a method and a system for steering assistance in the event of a steering servo failure.

[0014] This object is achieved by the method according to the characterizing part of patent claim 1. The object is also achieved by the system according to the characterizing part of patent claim 14, by the vehicle as well as by the computer program and computer program product.

[0015] The present invention provides a power steering assistance system in a vehicle that can be used to assist the steering in the event of a steering servo failure in the vehicle. According to the present invention, an intention of a driver of the vehicle is determined, wherein this intention is determined based on at least one sensor that at least partially receives vehicle-internal information. intern, i.e., information that is at least partially available within the vehicle. Subsequently, a current driving situation of the vehicle is determined, whereby these driving situations are determined on the basis of at least one sensor that at least partially receives vehicle-external information I extern , that is, information that is at least partially available outside the vehicle, and wherein the determination of the current driving situation is based on a current vehicle speed v act Based on the driver's intention and the current traffic situation, it is then determined whether there is a need for power steering assistance, i.e. steering support, whereby the need for power steering assistance increases with increasing current driving speed v actdecreases. If it is determined that there is a need for power steering assistance, this is provided according to the invention.

[0016] By utilizing the present invention, it can be ensured that safe maneuvering of the vehicle can always be enabled, even in the event of steering servo system failures and / or engine shutdown. This is ensured by providing power steering assistance when a steering servo system failure and / or engine shutdown occurs.

[0017] The present invention can be implemented with extremely low manufacturing cost overhead. The system according to the present invention largely utilizes systems, information, and / or sensors that are typically already present in the vehicle, so the present invention can be implemented without significantly increasing the vehicle's hardware complexity. Short description of the characters

[0018] The invention will be described in detail with reference to the accompanying drawings, in which like reference numerals are used for like parts. Fig. 1 shows an example vehicle in which the present invention can be implemented. Fig. Figure 2 shows a flow diagram for a process according to the present invention. Fig. 3 shows a control unit in which the present invention can be implemented. Description of the preferred embodiments

[0019] Fig. Figure 1 schematically shows a vehicle 100, for example, a heavy vehicle such as a truck or a bus, in which the present invention can be implemented. The figure only schematically and simplified shows the parts of the vehicle that can be used to describe the present invention.

[0020] The vehicle has at least two rotatable wheels 101, 102. The vehicle further has at least two additional wheels 103, 104. The rotatable wheels 101, 102 are rotated by the driver turning a steering wheel 105 in the vehicle, which causes a steering rod / column / axle 106 to rotate. The rotation of the steering rod 106 can be transmitted, for example, by a rack and pinion steering device 107, to a linear movement of a steering arm 109 and a steering strut / parallel strut 108 coupled to the rotatable wheels 101, 102, and thus the wheels 101, 102 can be rotated when the steering wheel is turned. In detail, the rack and pinion steering device 107 may, for example, comprise a ball-nut steering gear in which the power from the steering wheel axis 106 is transmitted to a steering gear by means of a threaded screw, and in which the threads may be equipped with balls similar to a ball bearing to facilitate turning.A nut is mounted on the threaded screw to transmit the screw's motion to a steering column shaft. From the steering column shaft, the power can be transmitted via a steering column arm and a steering arm 109 to a steering knuckle, allowing the wheel 101 to rotate. The steering strut / parallel strut 108 is positioned between the wheels 101, 102 so that the wheels can be pivoted in the same way / simultaneously.

[0021] As previously mentioned, the steering wheel 105 must be turned with a relatively large force if the wheels 101, 102 are to be turned, especially in heavy vehicles and at low speeds. Therefore, vehicles are often equipped with a steering servo system to make the vehicle easier to steer. The steering servo system also dampens shocks and jolts from the road surface.

[0022] Conventionally, only hydraulic steering servo systems are used, which are driven by a motor 141 in the vehicle, wherein the motor 141 is used to set the hydraulic fluid into a volume flow at a certain pressure in order to drive a hydraulic pump 112.

[0023] A hydraulic steering servo system also includes, among other things, a hydraulic fluid reservoir 113 and a valve device 111.

[0024] The valve device 111 is arranged on the steering wheel rod 106 to ensure that low-pressure hydraulic fluid is circulated in the steering servo system when the steering wheel is in the neutral position, i.e., when driving straight ahead. The valve device 111 is further arranged to cause the hydraulic pressure to increase when the steering wheel leaves the neutral position, i.e., when the steering wheel is turned. The valve device 111 is thus arranged to open / close depending on whether the steering wheel rod 106 is turned or not. This allows the force generated by the pressurized flow of hydraulic fluid when the steering wheel is turned by the driver to be used to assist the turning of the wheels, for example, with the aid of the rack device 107.

[0025] There are also exclusively electric power steering systems in which a torque sensor 121 can be arranged on the steering rod 106 to detect a torque with which the steering rod 106 is rotated when the driver turns the steering wheel 105. The torque sensor 121 is coupled to an electric motor 122 that assists in rotating the steering rod 106. Thus, the electric motor 122 generates a force that is used to assist in rotating the wheels 101, 102, for example, with the aid of the rack and pinion device 107.

[0026] There are also electro-hydraulic steering servo systems that include both a hydraulic steering servo system 111, 112, 113 and an electric steering servo system 121, 122. In an electro-hydraulic steering servo system, the hydraulic steering servo system 111, 112, 113 may be less powerful than in a purely hydraulic steering servo system.

[0027] As previously mentioned, there is a risk of steering servo failure when faults occur in a hydraulic steering servo system and / or in an electric steering servo system and / or when the motor 141 stops, whereby the hydraulic pump 112 is no longer driven.

[0028] As described in detail below, the vehicle 100 comprises a control unit 300 that implements the method according to the present invention. The control unit 300 comprises a first locking unit 310, a second locking unit 320, a third locking unit 330, and a steering servo unit 340. These units 310, 320, 330, 340 are shown in the figure as separate units 310, 320, 330, 340. However, the units may also be logically separate but physically implemented in the same unit, or may be arranged / implemented together in units both logically and physically. Those skilled in the art will appreciate that the control unit 300 may further be configured to control one or more other units in the vehicle (not shown in the figure).

[0029] The present invention provides, in one aspect, a method for power steering assistance in a vehicle that can be used to assist steering in the event of a steering servo failure in the vehicle.

[0030] According to the present invention, in a first step 201 of the method, for example by using the first detection unit 310 described below, an intention of a driver of the vehicle is determined, said intention being determined on the basis of at least one sensor which at least partially receives vehicle-internal information I intern that is, information that is at least partially available within the vehicle.

[0031] Subsequently, in a second step 202 of the method, for example by using the second detection unit 320 described below, a current driving situation of the vehicle is determined, wherein this driving situation is determined on the basis of at least one sensor which at least partially receives vehicle-external information I extern i.e. information that is at least partially available outside the vehicle.

[0032] Thereafter, in a third step 203 of the method, for example by using the third detection unit 330 described below, it is determined on the basis of the determined intention of the driver and the determined existing traffic situation whether there is a need for power steering assistance, that is to say steering support.

[0033] If it is determined that there is a need for power steering assistance, this power steering assistance is provided in a fourth step 204 of the method, for example by using the steering servo unit 340 described below.

[0034] According to an embodiment of the present invention, the need for power steering assistance increases with increasing current vehicle speed v act away.

[0035] In a corresponding way, the need for power steering assistance decreases as the current vehicle speed v act For example, if the vehicle is stationary, it is virtually impossible for the driver to turn the steering wheel in the event of a power steering failure if no power steering assistance is provided.

[0036] By utilizing the present invention, it can be ensured that safe maneuvering of vehicles can always be enabled, even in the event of a steering servo failure due to errors in the steering servo system and / or an engine stop.

[0037] The present invention can be implemented with extremely low manufacturing cost overhead. The system according to the present invention utilizes systems and sensors that are typically already present in the vehicle, so the present invention can be implemented without significantly increasing the vehicle's hardware complexity.

[0038] There are a number of different measures that can be taken to implement power steering assistance according to various embodiments of the present invention. For different types of power steering systems, different measures can be taken to implement power steering assistance. The possible measures for the respective steering servo systems are listed in the following paragraph.

[0039] If the steering servo system is an exclusively hydraulic steering servo system and one or more faults occur in its hydraulic steering servo systems 111, 112, 113, power steering assistance can be provided by activating the braking of at least one wheel 101, 102, 103, 104 on the vehicle 100 by activating at least one corresponding braking device 151, 152, 153, 154 on the respective wheel. By selectively braking certain wheels by activating selected braking devices 151, 152, 153, 154, the vehicle can be turned. For example, if only the braking devices 151, 154 on the left side of the vehicle in the direction of travel are activated, turning the vehicle to the left is assisted. Accordingly, activating only the braking devices 152, 153 on the right side of the vehicle in the direction of travel assists the vehicle in pivoting to the right.

[0040] Functions and / or models can be established for the geometric behavior of the front end of the vehicle. Based on these functions and / or models, the relationship between various applied braking torques and rotational / pivoting movements of the vehicle can then be determined. Thus, a specific desired rotation of the wheels 101, 102 can be related to a specific applied braking torque.

[0041] Functions and / or models for aligning moments and masses on the wheels can also be defined, allowing the road surface and its friction to be taken into account when activating braking. This also allows braking to be optimized, for example, taking into account a slippery road surface.

[0042] The braking torque that must be transmitted to cause the desired rotations of the wheels 101, 102 and thus the desired pivoting of the vehicle can be calculated for the respective driving situations or can be calculated in advance and stored in the memory / maps.

[0043] If the steering servo system is an exclusively hydraulic steering servo system and one or more faults occur in its hydraulic steering servo systems 111, 112, 113, power steering assistance can be provided by activating a starter motor 142 in the vehicle. This measure causes power steering assistance to be provided, for example, when the engine is at a standstill, i.e., during an engine stop, whereby the hydraulic steering servo system 111, 112, 113 no longer functions because its pump 112 is no longer driven by the engine. When the starter motor 142 is activated to rotate the motor 141, the motor 141 is rotated, for example, at approximately half idle speed, allowing the pump 112 to rotate again. When the pump 112 is rotated, the hydraulic pressure and flow return to levels that enable acceptable function of the hydraulic steering servo system 111, 112, 113.

[0044] The measures for providing power steering assistance for exclusively hydraulic steering servo systems are summarized below in Table 1. Table 1. Hydraulic steering servo system only Cause of a steering servo failure Power steering assistance Fault in the hydraulic system Activate braking device Engine stop Activate starter motor

[0045] If the steering servo system is instead an electro-hydraulic steering servo system and one or more faults occur in its hydraulic steering servo systems 111, 112, 113, power steering assistance may be provided by activating the braking of at least one wheel 101, 102, 103, 104 on the vehicle 100 by activating at least one corresponding braking device 151, 152, 153, 154 on the respective wheel. By selectively braking certain wheels by activating selected braking devices 151, 152, 153, 154, the vehicle may be steered as previously described.

[0046] If the steering servo system is an electrohydraulic steering servo system and one or more faults occur in its hydraulic steering servo systems 111, 112, power steering assistance can be provided by activating a starter motor 142 in the vehicle. This measure causes power steering assistance to be provided, for example, when the engine is at a standstill, i.e., during an engine stop, whereby the hydraulic steering servo system 111, 112, 113 no longer functions because its pump 112 is no longer driven by the motor 141. When the starter motor 142 is activated to rotate the motor 141, the pump 112 is rotated again, whereby the hydraulic pressure and flow return to levels that enable acceptable function of the hydraulic steering servo system 111, 112, 113.

[0047] If the steering servo system is an electro-hydraulic steering servo system and one or more faults occur in its hydraulic steering servo systems 111, 112, 113, power steering assistance can be provided by activating the electric steering servo system 121, 122. The electro-hydraulic steering servo system thus already has two integrated possible systems that, in a sense, provide redundant power steering capability. According to the present invention, if it is determined 203 that there is a need for power steering assistance because the hydraulic steering servo system is not functioning properly, steering servo assistance can thus be provided with the electric steering servo system 121, 122.The electric motor 122 typically consumes less power than that required to drive the starter motor 142; therefore, it may be advantageous to primarily use the electric motor 122 to provide power steering assistance, particularly when a battery in the vehicle is not fully charged. Alternatively, the choice between activating the starter motor 142 and the electric motor 122 to provide power steering assistance may be based on the battery's charge level.

[0048] The measures for providing power steering assistance for electro-hydraulic steering servo systems are summarized below in Table 2. Table 2. Electro-hydraulic steering servo system Cause of a steering servo failure Power steering assistance Fault in the hydraulic system Activate braking device Engine stop Activate starter motor Fault in the hydraulic system Activate electric steering servo system

[0049] If the steering servo system is an exclusively electric steering servo system and one or more faults occur in these electric steering servo systems 121, 122, power steering assistance can be provided by activating the braking of at least one wheel 101, 102, 103, 104 on the vehicle 100 by activating at least one corresponding braking device 151, 152, 153, 154 on the respective wheel. By selectively braking certain wheels by activating selected braking devices 151, 152, 153, 154, the vehicle can be steered as previously described.

[0050] The measures for providing power steering assistance for exclusively electric steering servo systems are summarized below in Table 3. Table 3. Electric power steering system only Cause of a steering servo failure Power steering assistance Electrical faults Activate braking device

[0051] As previously described, according to the present invention, at least one sensor 131 is used which at least partially receives vehicle-internal information I intern when a determination 201 of the driver's intention is to be made. This at least one sensor 131 may, according to various embodiments of the present invention, comprise or utilize a torque sensor arranged to detect a torque at a steering wheel 105 in the vehicle, to detect a torque 106 at a steering column 106 in the vehicle, or to detect a torque at a steering device 107 in the vehicle. Fig.In Figure 1, this is schematically illustrated by the fact that the sensor 131 is coupled to the torque sensor 121 in the electric steering servo system. However, the sensor 131 should also be capable of being coupled in a corresponding manner to the valve device 111 for the hydraulic steering servo system or to another torque sensor on the steering rod / column 106 and / or in the steering device 107.

[0052] According to one embodiment, the at least one sensor 131 may include one or more camera devices 134 arranged to identify one or more movements of the driver of the vehicle. Thus, the vehicle-internal information I internhere include image and / or video-related information. These one or more camera devices 134 may include a mono camera that generates images from one position, a stereo camera that generates images from two positions, and / or an active camera that generates images using projections. The mono camera is thus a conventional camera with one set of lenses with which images can be captured. The stereo camera has two sets of lenses with which images can be captured. These two sets of lenses are arranged at different locations in space with a spacing in a manner similar to how human eyes are arranged with a spacing; this allows the distance in depth to be assessed, whereby three-dimensional information can be determined by the stereo camera.The active camera comprises a projection device used to determine the position and movement of the driver of the vehicle in a similar way to how active cameras are often used in modern game consoles, for example, to enable the player to control the game by moving his body in front of the active camera of the game console.

[0053] The vehicle-internal information Ii ntern , comprising image and / or video-related information, can then be used to identify one or more movements of the driver. This identification of movements can involve a variety of steps.

[0054] A first step may include the inclusion in the vehicle's internal information I internOne or more objects associated with the driver are identified, for example by identifying a part of the driver's body. For example, parts of the face and / or one or more extremities such as an arm or a leg can be identified as objects of interest for further analysis.

[0055] These one or more identified objects are then classified in a subsequent step. For example, an object can be classified as "nose," "eye," "finger," "arm," and / or "leg." A person skilled in the art will understand that a large number of body parts can be classified in a similar manner.

[0056] The identified and classified objects are then analyzed to determine whether they are moving in space. One or more directional vectors are determined in a single step for at least one of the one or more identified objects, thereby detecting the object's movement.

[0057] These one or more detected directional vectors are then compared with respective corresponding thresholds and / or statistical models in a subsequent step, whereby detected movements of the object can be identified. For example, it can be identified whether the driver is looking right / left / straight ahead, whether the driver is moving their arms to turn the steering wheel, for example, or whether the driver is moving an arm, hand, and / or finger to operate a direction indicator, for example. A large number of different movements of the object can be identified, only a few of which are mentioned here. These identified movements can then be used to determine the driver's intentions.For example, if the driver looks to the left, attempts to turn the steering wheel to the left, and / or moves to signal the left turn indicator, these identified movements can be interpreted as the driver intending to turn left.

[0058] The at least one sensor 131, which at least partially receives vehicle-internal information I internmay also include or be connected to other types of sensors. For example, one or more capacitive sensors 133 may be used to determine the driver's intention. At least one of these one or more capacitive sensors 133 may be arranged in the steering wheel 105 of the vehicle and can then be used to detect the driver's turning of the steering wheel 105. For example, a steering wheel may be equipped with a number of capacitive sensors at the locations on the steering wheel where the driver holds the steering wheel. During different turns of the steering wheel, the driver's hand exerts different pressure on the steering wheel at different locations, which can be detected with the capacitive sensors 133. For example, if the driver attempts to turn left, the pressure on the steering wheel in the upper part of the driver's right hand becomes greater than the pressure on the steering wheel in the lower part of the driver's right hand.When multiple capacitive sensors are arranged, they detect pressure on the steering wheel at different parts of the steering wheel according to the positions where the upper and lower parts of the driver's right hand rest on the steering wheel, thus identifying, for example, a driver's intention to turn left. Similarly, an intention to turn right can also be identified.

[0059] The driver's seat position and changes in seat position can also be interpreted to identify the driver's intention. Therefore, according to one embodiment of the present invention, at least one of the one or more capacitive sensors is arranged in a driver's seat in the vehicle to detect how the driver moves in the seat while driving the vehicle.

[0060] According to the present invention, a current driving situation of the vehicle is determined 202 on the basis of at least one sensor 132, which at least partially receives vehicle-external information I extern as previously mentioned.

[0061] Determining the current driving situation can be based, for example, on location information combined with information about a road section ahead of the vehicle. Information about a road section ahead can include information based on the topography, curvature, and / or roadway of the road section ahead. Information can also include a driving pattern exhibited by other vehicles driving or having driven on the road section ahead.

[0062] Information about the road section ahead can be provided based on map data, for example, digital maps. Information can also be provided based on information from one or more vehicles that communicate directly with vehicle 100 (V2V) or communicate with vehicle 100 via one or more vehicle-external units such as servers, clouds, or the like (V2X). In a system that utilizes information exchange between vehicles, the information estimated by one vehicle can also be made available to another vehicle directly or via an intermediate unit such as a database or the like. Information can also be provided by a camera device 132 and / or a radar device 132 in the vehicle.

[0063] The at least one sensor which at least partially receives vehicle-external information I externwhich are necessary to determine the current driving situation, may comprise a positioning device 132 arranged to provide positioning information corresponding to the position of the vehicle. This positioning device may, for example, consist of a device for determining GPS (Global Positioning System) information or information from other positioning systems suitable for this purpose.

[0064] The at least one sensor which at least partially receives vehicle-external information I externwhich are necessary to determine the current driving situation, may comprise a camera device and / or a radar device 132 which is arranged to identify objects with a known arrangement. The known arrangement of objects may be known, for example, from map data or from information provided by other vehicles. Such objects with a known arrangement may include one or more road signs, one or more lane markings, one or more guardrails, one or more roundabouts, one or more tunnel walls, one or more traffic lights and / or one or more other vehicles. Since the location of these objects is thus known and the camera device and / or a radar device 132 can identify the objects when the vehicle is located near these objects, the position of the vehicle can also be determined.

[0065] The location information can be used to determine the position of the vehicle relative to the map data, so that information can be extracted from map data.

[0066] Several modern cruise control systems utilize map data and positioning information for cruise control. Such systems can then provide map data and positioning information to the system for the present invention, thereby minimizing the additional complexity of determining the information.

[0067] According to one embodiment of the present invention, the determination of the current driving situation is based on a current vehicle speed v act that the vehicle has. As previously mentioned, the need for power steering assistance increases with increasing vehicle speed v actIn a corresponding manner, the need for power steering assistance decreases as the current vehicle speed v act For example, if the vehicle is stationary, it is virtually impossible for the driver to turn the steering wheel in the event of a power steering failure if no power steering assistance is provided.

[0068] The determination of the current driving situation can also be based on a friction coefficient of a road surface in a road section in front of the vehicle 100. The need for power steering assistance decreases as the friction coefficient decreases. Correspondingly, the need for power steering assistance increases as the friction coefficient increases. The friction coefficient of the road section can be determined, for example, based on information provided by a torque sensor and / or angle sensor arranged for measurement on a steering rod in the vehicle, by a sensor arranged for measuring wheel slip, and / or by an electric steering servo 121, 122. The friction coefficient of the road section can also be determined based on information provided by one or more other vehicles directly or via one or more vehicle-external units (V2V / V2X), as previously described.

[0069] For example, if there are patches of ice and / or grit on the road, this can be taken into account when controlling the braking described above as power steering assistance, since harsh braking may be inappropriate when friction is low due to ice and / or grit. For braking based on functions and / or models for aligning moments and masses at the wheels, the friction coefficient of the road surface can be taken into account, thus achieving braking optimized for the road surface.

[0070] It will be apparent to those skilled in the art that a method for providing power steering assistance according to the present invention may further be implemented in a computer program which, when executed on a computer, causes the computer to carry out the method. The computer program is typically a component of a computer program product 303, wherein the computer program product comprises a suitable digital non-volatile / permanent / persistent / long-lasting storage medium on which the computer program is stored. The non-volatile / permanent / persistent / long-lasting computer-readable medium consists of a suitable memory such as: ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), flash memory, EEPROM (Electrically Erasable PROM), hard disk drive, etc.

[0071] Fig.3 schematically shows a control unit 300. The control unit comprises a calculation unit 301, which can consist of essentially any suitable type of processor or microcomputer, for example a digital signal processor (DSP) or a circuit with a predetermined specific function (Application Specific Integrated Circuit, ASIC). The calculation unit 301 is connected to a memory unit 302 arranged in the control unit 300, which provides the calculation unit 301 with, for example, the stored program code and / or the stored data that the calculation unit 301 requires to be able to perform calculations. The calculation unit 301 is also arranged to store partial or final results of the calculations in the memory unit 302.

[0072] Furthermore, the control unit 300 is equipped with devices 311, 312, 313, 314 for receiving and transmitting input and output signals, respectively. These input and output signals may comprise waveforms, pulses, or other attributes that are recognized as information by the input signal receiving devices 311, 313 and can be converted into signals that can be processed by the calculation unit 301. These signals are then provided to the calculation unit 301. The devices 312, 314 for transmitting output signals are arranged to convert the calculation result from the calculation unit 301 into output signals for transmission to other parts of the control system of the vehicle and / or the component(s) for which the signals are intended, for example to the braking system 151, 152, 153, 154, to the starter motor 142 and / or to a steering servo system 111, 112, 113, 121, 122.

[0073] Each of the connections on the devices for receiving or transmitting input or output signals may consist of one or more cables; a data bus, such as a CAN bus (Controller Area Network bus), a MOST bus (Media Oriented Systems Transport bus), or another bus configuration; or a wireless connection.

[0074] It will be clear to a person skilled in the art that the computer may consist of the calculation unit 301 and that the memory may consist of the storage unit 302.

[0075] Generally, the control system in modern vehicles consists of a communication bus system, which consists of one or more communication buses for coupling a number of electronic control units (ECUs) or controllers and various components located in the vehicle. Such a control system may comprise a large number of control units, and responsibility for a particular function may be divided among more than one control unit. Vehicles of the type shown thus often comprise considerably more control units than in Fig. 1 and Fig. 3 shows what is clear to a person skilled in the technical field.

[0076] In the embodiment shown, the present invention is implemented in the control unit 300. However, the invention may be implemented entirely or partially in one or more other control units already present in the vehicle or in a control unit provided separately for the present invention.

[0077] In the present specification, units are often described as being arranged to carry out steps of the method according to the invention. This also means that the units are adapted and / or arranged to carry out these method steps.

[0078] The at least one control unit 300 is in Fig.1 is illustrated as comprising, for example, separately designated units 310, 320, 330, 340. The units 310, 320, 330, 340 may be logically separate but physically implemented in the same unit, or may be arranged / implemented together both logically and physically. For example, the units 310, 320, 330, 340 may correspond to different groups of instructions, for example in the form of program code, that are supplied to and used by a processor, wherein the respective unit is active / used to execute the respective method step.

[0079] The present invention, in one aspect, provides a system for power steering assistance in a vehicle that can be used to provide steering assistance in the event of a steering servo failure in the vehicle 100.

[0080] According to the present invention, the system comprises a first determination unit 310 arranged to determine 201 an intention of a driver of the vehicle, wherein the first determination unit 310 is arranged to determine the intention on the basis of at least one sensor 132 which at least partially receives vehicle-internal information I intern that is, information that is at least partially available within the vehicle 100.

[0081] The system further comprises a second detection unit 320, which is arranged to detect 202 a current driving situation of the vehicle, wherein the second detection unit 320 is arranged to detect the driving situation on the basis of at least one sensor which at least partially receives vehicle-external information I extern i.e. information that is at least partially available outside the vehicle.

[0082] The system further comprises a third determination unit 330 which is arranged to determine 203, on the basis of the determined intention of the driver and the determined existing traffic situation, whether there is a need for power steering assistance, i.e. steering support.

[0083] The system further includes a steering servo unit 340 arranged to provide 204 the power steering assistance when it is determined that there is a need for power steering assistance.

[0084] By utilizing the present invention, it can be ensured that safe maneuvering of vehicles can always be enabled, even in the event of a steering servo failure due to errors in the steering servo system and / or an engine stop.

[0085] The present invention can be implemented with extremely low manufacturing cost overhead. The system according to the present invention utilizes systems and sensors that are typically already present in the vehicle, so the present invention can be implemented without significantly increasing the vehicle's hardware complexity.

[0086] The system according to the present invention can be arranged to carry out all the method embodiments described above and in the claims, the system for the respective embodiment having the advantages of the respective embodiment described above.

[0087] It will be apparent to those skilled in the art that the system described above can be modified according to the various embodiments of the method according to the invention. Furthermore, the invention relates to a motor vehicle 100, for example a truck or a bus, comprising at least one system for providing power steering assistance.

[0088] The present invention is not limited to the embodiments of the invention described above, but relates to and includes all embodiments within the scope of the appended independent claims.

Claims

[1] A method for providing power steering assistance in a vehicle (100), the vehicle (100) further comprising a steering servo system and a motor coupled thereto, characterized in that a steering servo failure is detected due to a fault in the steering servo system and / or an engine stop, and the following is carried out in the case of the steering servo failure: - determining (201) an intention of a driver of the vehicle (100) on the basis of at least one sensor (131) which at least partially receives vehicle-internal information I intern catches up; - determining (202) a current driving situation of the vehicle (100) on the basis of at least one sensor (132) which at least partially receives vehicle-external information I extern , whereby the determination of the current driving situation is based on a current vehicle speed v act is based; - determining (203) on the basis of the determined intention of the driver and the determined existing traffic situation whether there is a need for power steering assistance, wherein the need for power steering assistance increases with an increase in the current driving speed v act decreases; and - providing (204) the power steering assistance when it is determined that the need exists. [2] Method according to claim 1, wherein the steering servo failure is based on at least one element of the following group: - one or more faults in a hydraulic steering servo system (111, 112, 113) in the vehicle (100); - one or more faults in an electric steering servo system (121, 122) in the vehicle (100); and - an engine stop of an engine (141) in the vehicle (100). [3] Method according to claim 2, wherein the power steering assistance in the case of one or more faults in the hydraulic steering servo systems (111, 112, 113) in an exclusively hydraulic steering servo system comprises one or more measures from the following group: - activation of the braking of at least one wheel (101, 102, 103, 104) of the vehicle (100); and - activation of a starter motor (142) of the vehicle (100). [4] Method according to claim 2, wherein the power steering assistance in the case of one or more faults in the hydraulic steering servo systems (111, 112, 113) in an electro-hydraulic steering servo system comprises one or more measures from the following group: - activation of the braking of at least one wheel (101, 102, 103, 104) of the vehicle (100); - activation of a starter motor (142) of the vehicle (100); and - activation of the electric steering servo systems (121, 122). [5] Method according to claim 2, wherein the power steering assistance comprises activating the braking of at least one wheel (101, 102, 103, 104) of the vehicle (100) in the case of one or more faults in the electric steering servo systems (121, 122) in an exclusively electric steering servo system. [6] Method according to one of claims 1 to 5, wherein the at least one sensor (131) which at least partially receives vehicle-internal information I intern to determine the driver's intention, includes one or more sensors from the following group: - a torque sensor arranged to detect a torque on a steering wheel (105) in the vehicle (100); - a torque sensor arranged to detect a torque on a steering column (106) in the vehicle (100); and - a torque sensor arranged to detect a torque in a steering device (107) in the vehicle (100); [7] Method according to one of claims 1 to 6, wherein the at least one sensor (131) which at least partially receives vehicle-internal information I intern for determining the driver's intention, comprises one or more camera devices (134) arranged to identify one or more movements of the driver, wherein the identification of the one or more movements of the driver comprises: - Identification of one or more objects associated with the driver; - Classification of the one or more identified objects; - determining one or more direction vectors for at least one of the one or more identified objects; and - Comparison of the one or more direction vectors with respective thresholds and / or statistical models. [8] Method according to one of claims 1 to 7, wherein the at least one sensor (131) which at least partially receives vehicle-internal information I intern for determining the driver's intention, comprises one or more capacitive sensors (133), wherein at least one of the one or more capacitive sensors (133) is arranged in a steering wheel (105) in the vehicle (100) for detecting how the driver turns the steering wheel (105), and / or at least one of the one or more capacitive sensors (133) is arranged in a driver's seat in the vehicle (100) for detecting how the driver moves. [9] Method according to one of claims 1 to 8, wherein the determination of the present driving situation is based on location information in combination with information about a road section in front of the vehicle (100), wherein the information about the road section in front comprises information based on one or more of the following elements: - a topography of the road section ahead; - a curvature of the road section ahead; - a carriageway of the road section ahead; and - a driving pattern of other vehicles driving on the road section ahead. [10] Method according to claim 9, wherein the at least one sensor (132) which at least partially receives vehicle-external information I extern for determining the driving situation, includes one or more of the following elements: - a locating device (132) for providing the location information for the vehicle (100); - a camera device (132) arranged to identify objects having a known arrangement; and - a radar device (132) arranged to identify objects having a known arrangement. [11] Method according to one of claims 1 to 10, wherein the determination of the present driving situation is based on a friction coefficient of a roadway in a road section in front of the vehicle (100), wherein the need for power steering assistance decreases with a decrease in the friction coefficient. [12] A computer program comprising program code which, when executed on a computer, causes the computer to carry out the method according to any one of claims 1 to 11. [13] A computer program product comprising a computer-readable medium and a computer program according to claim 12, wherein the computer-readable medium comprises the computer program. [14] A system for providing power steering assistance in a vehicle (100), the vehicle (100) further comprising a steering servo system and a motor coupled thereto, characterized by - a control unit (300) configured to detect a steering servo failure due to a steering servo system fault and / or an engine stop, - a system for determining an intention of a driver of the vehicle (100) in the event of a steering servo failure on the basis of at least one sensor (131) which at least partially receives vehicle-internal information I intern arranged first locking unit (310); - a system for determining a current driving situation of the vehicle (100) on the basis of at least one sensor (132) which at least partially receives vehicle-external information I extern arranged second locking unit (320), wherein the detection of the present driving situation is based on a current vehicle speed v act is based; - a third detection unit (330) arranged to determine, on the basis of the detected intention of the driver and the detected existing traffic situation, whether there is a need for power steering assistance, wherein the need for power steering assistance increases with an increase in the current driving speed v act decreases; and - a steering servo unit (340) arranged to provide the power steering assistance when it is determined that the need exists.

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