DE102022116650A1 - Improved determination of torque to be applied in an electric power steering system - Google Patents

Abstract

The present invention relates to a method for determining a torque to be applied in an electric power steering system (26) of a steering system (28) of an ego vehicle (10), with at least one steering support function acting on the electric power steering system (26), comprising the steps of receiving a requested torque from the at least one steering assistance function, determining a torque applied by a human driver to the steering system (28), determining an intention of the human driver to apply the torque to the steering system (28), and determining the torque in the electric power steering system (26 ) torque to be applied based on the torque requested by the at least one steering assistance function, the specific torque applied to the steering system (28) by a human driver, and the human driver's specific intention to apply the torque to the steering system (28). The present invention also relates to a corresponding electric power steering system (26) for determining a torque to be applied in a steering system (28) of an ego vehicle (10) with at least one steering support function acting on the electric power steering system (26). The present invention further relates to a steering assistance system (12), which comprises the above electric power steering system (26).

Description

The present invention relates to a method for determining a torque to be applied in an electric power steering system of a steering system of an ego vehicle with at least one steering assistance function acting on the electric power steering system, comprising the step of receiving a torque requested by the at least one steering assistance function.

The present invention also relates to an electric power steering system for determining a torque to be applied in a steering system of an ego vehicle, with at least one steering assistance function acting on the electric power steering system, comprising a control unit and a drive unit which is controlled by the control unit in order to obtain the determined torque in the Apply steering system, wherein the control unit receives a torque requested by the at least one steering support function.

The present invention also relates to a steering assistance system, in particular as a lane centering system or lane keeping system, which includes the above electric power steering system.

Various types of driving support systems are known, for example to support a human driver when driving an ego vehicle. Such driving support systems to support the human driver are often also referred to as ADAS (Advanced Driver Assistance Systems). Other driving support systems may provide autonomous driving functions and/or support an autonomous driving system of the ego vehicle. Different levels of autonomous driving can be applied, with the highest level 5 relating to fully autonomous driving.

In this field, driving assistance systems include systems that support the steering of the vehicle, which is also referred to as steering assist functions (SAF) or steering assistance functions. In this context, steering support functions such as lane centering systems (LCS) or lane keeping systems (LKS) help the human driver to keep the ego vehicle on a predetermined path, usually in the middle of the lane in the case of lane centering systems or within the lane boundaries in the case of lane keeping systems. The SAF functions influence the direction of travel of the ego vehicle by controlling the steering system of the ego vehicle, in particular using electric power steering (EPS).

EPS, sometimes referred to as motor-driven power steering (MDPS), uses an electric motor instead of a traditional hydraulic system to assist the human driver of the ego vehicle. Sensors detect the position of the steering wheel and the torque applied in the steering column, and a computer module applies assisting torque via the electric motor connected to either the steering gear or the steering column. In this way, different types of assistance can be applied including the functions already mentioned such as lane departure warning, wind drift correction or others. Typical EPS systems offer variable support, particularly depending on the speed of the ego vehicle. Therefore, different levels of support can be applied, which can depend, for example, on the driving conditions such as the speed of the ego vehicle.

So when SAF is active, the ego vehicle typically influences the steering angle of the ego vehicle via the EPS system. However, in some situations it may be necessary or desirable for the driver of the ego vehicle to influence the path of the ego vehicle, for example to avoid a pothole or to maintain a distance from a neighboring vehicle, which may be a different requirement than LCS or LKS . Other driving situations in which the human driver of the ego vehicle needs or wants to influence the vehicle's path include overtaking trucks, especially on the highway, or even overtaking a parked vehicle on urban/interurban roads. To change the path of the ego vehicle, the human driver may need to overcome the torque applied by the SAF system and additionally apply torque to change the path. This may be uncomfortable or uncomfortable for the human driver as he may feel that the SAF is resisting his steering inputs while the SAF attempts to maintain the path set by the SAF, e.g. to keep the ego vehicle in the case of the LCS to position a predetermined reference position within a lane.

To solve this problem, the SAF functions monitor the state of the steering angle, such as position and speed, and the torque applied by the human driver. If the SAF determines that the human driver is overriding the SAF, the SAF may temporarily deactivate itself so that the human driver can change the route without the SAF counteracting the driver's steering inputs. Alternatively, the SAF may temporarily apply a different torque, for example by scaling the torque based on the steering torque applied by the driver.

Determining logic and thresholds for disabling the SAF based on human driver override is complicated. More sensitive deactivation settings often result in false positive deactivations. In contrast, less sensitive settings result in a reduction in driver comfort. Reducing the torque applied by the SAF can be more comfortable for the driver as they can steer more freely but are still able to feel the intervention of the SAF system. However, both methods can result in unwanted changes to the ego vehicle's path if the system makes a false positive deactivation of the SAF.

In this context the document concerns US 2015 0012182 A1 supporting a vehicle driver in a constriction, including the tasks of reading, evaluating and providing. When reading in, information about a passable corridor in the narrowing, information about a current trajectory of the vehicle in the narrowing and information about a steering torque that the driver is currently exerting on steering the vehicle are read. During evaluation, the information about the corridor, the trajectory and the steering torque is evaluated based on known dimensions of the vehicle in order to detect an expected violation of the corridor by at least part of the vehicle. When provided, a counter-torque control signal is provided which, when the violation is detected, acts against the steering torque to assist the driver in avoiding the injury.

Both the document US 2016 0152233 A1 as well as the document US 2018 0072310 A1 concerns the assessment of driver behavior including the monitoring of vehicle systems and driver monitoring systems to take into account a driver's slow reaction time, lack of attention and/or alertness. For example, if a driver is determined to be drowsy, the response system may alter the operation of one or more vehicle systems. Systems that can be modified include visual devices, audio devices, tactile devices, anti-lock braking systems, automatic brake priming systems, brake assist systems, automatic cruise control systems, electronic stability control systems, collision warning systems, lane departure warning systems, blind spot warning systems, electronic biasing systems and climate control systems.

The document US 2019 0315403 A1 relates to a vehicle control system installed in a vehicle and including an automatic steering control device configured to execute automatic steering control that determines a steering angle target value and controls the steering of the vehicle so that an actual steering angle corresponds to the steering angle target value follows. A stopped state detection device is configured to detect a stopped state of the vehicle. An oversteer detection device is configured to detect an oversteer operation by a driver of the vehicle. When the oversteer operation is detected in the stop state, the automatic steering control device prevents the actual steering angle from changing due to the automatic steering control until the vehicle starts moving.

It is the object of the present invention to provide a method for determining a torque to be applied in an electric power steering system of a steering system, an electric power steering system for determining a torque to be applied in a steering system and a steering assistance system which includes the above electric power steering system, which ensures safety in steering assistance functions increase driver comfort when overriding steering assistance functions and reduce false positive detections of such overrides.

This task is solved by the independent claims. Advantageous embodiments are specified in the dependent claims.

In particular, a method for determining a torque to be applied in an electric power steering system of a steering system of an ego vehicle with at least one steering support function acting on the electric power steering system is specified, comprising the steps of receiving a torque requested by the at least one steering support function, determining a torque that is provided by a human driver is applied to the steering system, determining an intention of the human driver to apply the torque to the steering system, and determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assistance function, the determined torque provided by a human driver is applied to the steering system, and the human driver's specific intention to apply the torque to the steering system.

In addition, an electric power steering system for determining a torque to be applied in a steering system of an ego vehicle with at least one steering assistance function acting on the electric power steering system is specified, comprising a control unit and a drive unit which is controlled by the control unit to apply the determined torque in the steering system , wherein the control unit receives a torque requested by the at least one steering assistance function, the control unit receives information about a torque applied to the steering system by a human driver, the control unit receives information about an intention of the human driver to apply the torque to the steering system , receives, and the control unit determines the torque to be applied in the steering system by controlling the drive unit based on the torque requested by the at least one steering assistance function, the determined torque applied to the steering system by a human driver, and the determined intention of the human driver to apply the torque to the steering system.

Furthermore, a steering assistance system is specified, in particular as a lane centering system or lane keeping system, comprising the above electric power steering system.

The basic idea of the invention is to confirm that a torque applied to the steering system by a human driver is intentionally applied. This is based on determining the torque applied by the human driver along with determining the human driver's intention to apply the torque to the steering system. This enables implementation of improved steering assistance functions with increased safety, improved driver comfort when overriding steering assistance functions and a reduction in the number of false positive detections of such overrides. A specific torque that the human driver intentionally applies to the steering system is processed differently than a specific torque that is applied to the steering system without intention.

The at least one steering assistance function, which is also referred to as a steering assistance function (SAF), requests a torque to be applied to the steering system in order to follow a specific route, the route being determined by the respective steering assistance function. Thus, when the SAF is active, the SAF requests the electric power steering (EPS) system to apply torque in the steering system to travel a path specified by the SAF.

In some situations, however, it may happen that the human driver of the ego vehicle has to or wants to take a different route, e.g. to avoid a pothole or to maintain a distance from a neighboring vehicle. In this case, the human driver intentionally applies torque to the steering system, particularly by turning a steering wheel of the steering system. In this case, the human driver's intention to apply the torque to the steering system is determined so that the torque to be applied by the EPS system can be determined based on the intended or desired override of the torque requested by the SAF. In this case, the human driver can easily change the ego vehicle's path based on the torque he or she applies.

However, in other situations, the human driver of the ego vehicle unintentionally turns the steering wheel and unintentionally applies torque to the steering system, such as when gripping the steering wheel and moving. In this case, a lack of intention of the human driver to apply the torque to the steering system is detected, so that the torque to be applied in the electric power steering system can be determined based on the unintentional or undesirable application of the torque to the steering system. Thus, no oversteering of the SAF takes place, a limited oversteering can occur or even a counter-torque can be applied to the steering system in order to achieve the goals defined by the respective driving support function(s). In each case, a total torque to be applied in the EPS system of the ego vehicle's steering system is determined and applied. The determination is carried out by the control unit of the electric power steering system, which controls the drive unit in order to apply the determined torque in the steering system.

The ego vehicle relates to a vehicle with a steering system and an electric power steering system, for which the method for determining a torque to be applied in the electric power steering system is carried out. The ego vehicle can be any type of driving equipment, including passenger cars (cars or buses), trucks, trucks and others.

Electric power steering, sometimes referred to as motor-driven power steering (MDPS), is a system that uses an electric motor instead of a traditional hydraulic system to assist the human driver of the ego vehicle. Sensors detect the position of the steering wheel and the torque applied in the steering column, and the drive unit is controlled to apply torque in the steering system. The electric power steering system can be any electrically or electronically operated steering system.

The steering system refers to a system that functionally connects a steering wheel located in a passenger compartment of the ego vehicle and the steered wheels of the ego vehicle, usually the front wheels. The steering wheel is attached to a steering column, which transmits the steering movement to the steered wheels via a steering gear. In some vehicles, parts of the steering system are provided electronically, also known as steer-by-wire. However, the principles of the present invention apply equally.

The at least one steering assistance function provides assistance when steering the vehicle. In this context, steering support functions such as lane centering systems (LCS) or lane keeping systems (LKS) help human drivers to keep the ego vehicle on a predetermined path, usually in the middle of the lane in the case of the lane centering systems or within the lane boundaries in the case of the lane keeping systems. The SAF influences the direction or path of the ego vehicle by instructing the ego vehicle's steering system to apply torque in the electric power steering. The SAF influences the EPS system. One or more steering assistance functions may be active simultaneously, with multiple steering assistance functions jointly requesting torque to the EPS system, or each of the EPS systems requests torque and the EPS system selects torque based on the different requirements. In addition, one of the SAFs may be permanently active while another SAF is only active in emergencies, such that the permanently active SAF constantly requests torque and the SAF that is active in emergencies overrides the permanently active SAF in emergencies.

As an alternative to receiving the torque requested by the at least one steering assistance function, the EPS system may also receive a requested steering angle from the at least one steering assistance function, which is used as a basis for determining the torque corresponding to the request from the at least one steering assistance function.

The at least one steering assistance function and the electric power steering system can be integrated in the ego vehicle or implemented as independent systems connected via any data connection.

The torque applied to the steering system by the human driver can be determined in different ways, for example using a corresponding torque sensor or, for example, based on an electrical power required by the drive unit to apply the determined torque.

The human driver's intention to apply the torque to the steering system is determined based on a behavior of the human driver. This behavior of the human driver may be an intentional behavior, such as when the human driver tries to pick up an object from the floor of the passenger compartment, or an unintentional behavior, such as in the case of a medical problem such as a heart attack or others. In addition, the behavior of the human driver can be easily determined based on the movement of, for example, the driver's arms or legs. In other cases, the behavior of the human driver can be determined, for example, based on an eye movement of the eyes of the human driver of the ego vehicle. For example, it is known to determine a person's state of fatigue based on eye movement.

Determining the torque to be applied in the electric power steering system involves determining the torque to ultimately be applied to the steering system.

The torque is determined based on the torque requested by the at least one steering assist function, the particular torque applied to the steering system by a human driver, and the human driver's particular intention to apply the torque to the steering system. If no torque is applied by the human driver, the torque requested by the at least one steering assistance function is applied by the electric power steering system.

Determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assist function, the determined torque applied to the steering system by a human driver, and the human driver's determined intention to apply the torque to the steering system, may include using the particular torque applied to the steering system by the human driver and the human driver's particular intention to apply the torque to the steering system, for example, to determine whether or not the requested torque is applied a different torque is applied. Determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assist function, the determined torque applied to the steering system by a human driver, and the human driver's determined intention to apply the torque to the steering system, does not require that the torque be determined using any logical combination of all of the at least one steering assist function requested torque, the particular torque applied to the steering system by a human driver, and the human driver's particular intention to apply the torque to the steering system to be raised, calculated or determined.

If the human driver applies torque, the electric power steering system performs validation of the torque applied by the human driver based on the human driver's determined intention to apply the torque to the steering system. Therefore, if the torque is intentionally applied by the human driver, the torque to be applied in the electric power steering is determined based on the torque requested by the at least one steering assistance function, the torque applied to the steering system by the human driver, and the human driver's determined intention to apply the torque to apply the steering system. This may include determining the torque to be applied based on the requested torque, which is changed based on the torque applied to the steering system by the human driver and/or the human driver's determined intention to apply the torque to the steering, as explained in more detail below . This may even include a complete oversteer or deactivation of the electric power steering system, i.e. the electric power steering system does not apply any torque to the steering system.

The control unit determines the torque to be applied in the electric power steering system for the steering system of the ego vehicle. The control unit controls the drive unit to apply the specific torque in the steering system. The control unit and the drive unit are connected via a control connection, which can be any analog or digital connection. The control unit can be any control unit that is suitable for use in the ego vehicle. Such control units are typically known in the automotive sector as ECUs (electronic control units). The control unit can be shared to run multiple tasks or applications. The control unit processes the received information as described below.

For example, the drive unit includes an electrically driven motor and applies a drive current based on the control signals received from the control unit. In this way, the drive unit can apply the specific torque in the steering system. The drive unit is typically connected to a steering column of the steering system and applies torque to the steering column.

The human driver's intention to apply torque to the steering system is generally based on the driver being focused on driving and actively and intentionally applying the torque. If the human driver of the ego vehicle is disturbed or distracted or is in some other condition that does not allow the intentional application of torque, the SAF can help overcome this situation and safely navigate a given path. In these cases, oversteering the SAF and the torque requested by the SAF can lead to dangerous driving situations. In particular, if the SAF is set more towards comfort, unintentional application of torque by the human driver is prevented. However, by confirming based on determining a human driver's intention to apply torque to the steering, inadvertent deactivation or override of the SAF and the torque requested by the SAF can be prevented. Therefore, the verification based on the human driver's determined intention to apply the torque to the steering system, on the one hand, enables a more comfortable driving experience with an improved ability to easily adjust the ego vehicle's travel path for intended travel path changes change, while on the other hand preventing unintentional changes in the travel path by, for example, providing reliable resistance to unintentional steering torque applied by the human driver.

According to a modified embodiment of the invention, the step of determining a human driver's intention to apply the torque to the steering system includes determining the human driver's intention to apply the torque to the steering system based on input received from a driver monitoring system. The driver monitoring system (DMS) can be an independent system or integrated into the SAF. Any set of sensors and information sources can be used to measure or estimate driver intent, e.g. cameras, a driver steering torque sensor, wearable devices, an entertainment system, a hands-free system. For example, the driver's intent may be determined based on a condition and/or attention of the human driver, which are typically provided as an output of the DMS. Therefore, existing driver monitoring systems can be used to provide appropriate input for determining the human driver's intention to apply torque to the steering system. Such DMS are known in technology and can, for example, determine the fatigue of the human driver.

According to a modified embodiment of the invention, the electric power steering system includes a driver monitoring system that determines the information about the human driver's intention to apply torque to the steering system and provides the information to the control unit. The DMS may additionally provide output for use by other functions and/or systems of the ego vehicle, e.g. to detect human driver fatigue and generate an alert in such cases.

Alternatively, the driver monitoring system is provided independently of the electric power steering system and provides the electric power steering system, in particular the control unit, with the information about the human driver's intention to apply the torque to the steering system. Accordingly, the DMS may be a multi-purpose system used by various functions and/or systems of the ego vehicle.

According to a modified embodiment of the invention, the step of determining an intention of the human driver to apply the torque to the steering system includes determining the intention of the human driver to apply the torque to the steering system based on at least one of a detection of the steering wheel positioned Hands of the driver, detecting distraction/attention of the driver while driving the ego vehicle, detecting drowsiness and/or fatigue of the driver of the ego vehicle, detecting a health condition of the driver of the ego vehicle, detecting blinding of the driver of the ego vehicle Vehicle, detecting that the driver of the ego vehicle is actively making a telephone conversation, actively using a mobile device and / or actively using any device of the ego vehicle, e.g. an entertainment system, and recognizing an environment of the ego vehicle, in particular in with regard to the presence of potholes, parked cars or any type of obstacles or other objects, in particular to validate the human driver's determined intention to apply torque to the steering system. If the human driver's hands are on the steering wheel, it can be assumed that the human driver is paying attention and is therefore only intentionally applying torque to the steering system. Distraction and lack of attention may indicate a lack of intention to apply torque to the steering system, for example when the human driver makes movements due to other activities and applies torque to the steering system due to such movement. Tiredness or fatigue typically indicates, or at least increases the likelihood of, non-intentional action, i.e., that the human driver has no intention of applying torque to the steering system. Depending on the health condition, the human driver may be unable to intentionally apply torque to the steering system, for example in the event of unconsciousness or death. Driver glare can occur from sunlight and/or lights from oncoming vehicles. This can be detected, for example, by typical movements of the human driver, such as closing the eyes or others, which makes it difficult for the human driver of the ego vehicle to intentionally steer the ego vehicle and thus intentionally apply the torque to the steering system. Using cell phones or other mobile devices while driving the ego vehicle is also a typical sign that the human driver is inattentive. Consequently, the human driver will not intentionally apply torque to the steering system.

Overall, the information provided is processed to determine information about the human driver, e.g., a measured or estimated condition along with a focus or intent of the human driver, whether or not the human driver is intentionally applying torque to the steering system. In addition, the driver's steering intention, that is, the human driver's intention to apply the torque to the steering system, can be based on the sensing of the ego vehicle's environment, that is, externally sensed objects/obstacles such as potholes, parked vehicles, etc. in the surroundings of the ego vehicle, to be determined/confirmed. Accordingly, a determination may be made to check whether the human driver's particular intention to apply torque to the steering system is consistent with the external environment. For example, the driver is likely to intentionally apply torque to the steering system when there is a pothole or other obstacle in front of the ego vehicle.

According to a modified embodiment of the invention, the step of determining a human driver's intention to apply the torque to the steering system includes determining the human driver's intention to apply the torque to the steering system as a quantified intention level, in particular between a minimum intention and a maximum intention, and the step of determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assist function, the determined torque applied to the steering system by a human driver, and the human driver's determined intention Applying torque to the steering system includes determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assist function, the determined torque applied to the steering system by a human driver, and the determined intent level. Thus, the determined intention level can be used to determine in detail the torque to be introduced into the electric power steering system, in particular by a calculation using the determined intention level as input. Furthermore, the determined intention level can be compared with threshold values, which can be defined in different ways, for example, to determine the torque. In particular, multiple threshold values can be defined, indicating, for example, a high, medium or low level of intent to determine and apply torque differently. Furthermore, the intent level allows easy determination of the torque to be applied, e.g., based on the requested torque and modification based on the intent level, e.g., as a simple mathematical calculation, especially when the intent level is specified as a number.

According to a modified embodiment of the invention, the step includes determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assistance function, the determined torque applied to the steering system by a human driver, and the determined intention of the human driver to apply the torque to the steering system, determining the torque to be applied in the electric power steering system by modifying the torque requested by the at least one steering assistance function in a binary, stepwise or continuous manner based on the determined torque applied to the steering system by the human driver is applied, and/or the human driver's determined intention to apply the torque to the steering system. The torque applied to the steering system by the human driver and the human driver's intention to apply the torque to the steering system may therefore be used individually or in combination to change the requested torque to determine the torque to be applied in the electric power steering system. For example, one or more of an absolute value of the torque applied to the steering system by the human driver, a difference between the requested torque and the torque applied to the steering system by the human driver, an intention level of the human's intention Driver to apply the torque to the steering system, or derivatives thereof are used to change the requested torque to determine the torque to be applied in the electric power steering system. The modification can be a simple change between two states, such as requested torque and zero, or between multiple states, such as requested torque, different percentages of requested torque and zero, or a calculation based on a mathematical formula such as torque equals requested torque minus Torque applied by the human driver.

According to a modified embodiment of the invention, the step includes determining the torque to be applied in the electric power steering system based on the torque requested by the at least one steering assistance function, the determined torque applied to the steering system by a human driver, and the determined intention of the human driver to apply the torque to the steering system, at least one of providing modified limits for the torque to be requested by the at least one steering assistance function, ie a saturation of the steering torque, determining the torque to be applied by scaling the torque requested by the at least one steering assistance function with a factor, changing an algorithm responsible for determining the torque to be applied based on the torque applied to the steering system by the human driver, changing feedback control parameters in a feedback controller for determining the torque to be applied in the electric power steering system, and changing a deactivation condition based on a Human driver override to disable torque application in the electric power steering system. Some of the above options can be applied to adaptively change a "resistance" of the steering wheel to the driver's steering, that is, a torque that must be applied by the human driver of the ego vehicle in order to move the steering wheel and the ego vehicle to be able to steer as desired. Some of the above options may be applied to allow adaptive changes to the conditions that result in deactivation of the electric power steering system, ie, no torque is applied from the electric power steering system. In this context, the limit values for the torque to be requested by the at least one steering assistance function can be changed in the respective steering assistance function or in the electric power steering system or in both. Scaling the torque requested by the at least one steering assistance function by a factor involves determining the torque to be applied in the electric power steering system with a torque value that is calculated using the requested torque as a starting point, and modifying this torque value by the factor, in particular as a function of the torque applied to the steering system by the human driver and/or the human driver's intention to apply the torque to the steering system. Also, modification can be made based on the torque applied to the steering system by the human driver. The feedback controller enables appropriate feedback control to smooth the torque to be applied in the electric power steering system. Changing parameters of the feedback controller enables faster or slower adjustment of the torque to be applied in the electric power steering system. The deactivation condition for deactivating the torque application in the electric power steering system may be modified so that, for example, in the event that the human driver concentrates less on driving and therefore applies the steering torque with less intention, the deactivation condition is tightened to prevent deactivation from occurring. Conversely, the deactivation condition is handled less strictly in order to enable quick deactivation, for example when the human driver is driving very concentratedly and therefore generally applies the steering torque intentionally, by assuming as a prerequisite that the human driver intentionally applies the torque. Overall, there are various ways to determine the torque to be applied in the electric power steering. These options can be used individually or in any suitable combination.

According to a modified embodiment of the invention, the method includes a step of generating a warning to the human driver when a discrepancy is detected between the torque applied to the steering system by the human driver and the human driver's particular intention to apply the torque to the steering system . The discrepancy between the torque applied to the steering system by the human driver and the human driver's specific intention to apply the torque to the steering system relates to a situation in which the human driver unintentionally applies the torque to the steering system. In this case, the warning may alert the human driver to prevent further inadvertent application of torque to the steering system. The warning can be an acoustic and/or visual warning that can be generated via any user interface of the ego vehicle.

According to a modified embodiment of the invention, the electric power steering system includes at least one sensor that provides sensor information to the control unit for determining the human driver's intention to apply torque to the steering system. The direct use of the at least one sensor overcomes limitations associated with use vention of known driver monitoring systems that currently focus on the condition/condition of the human driver. Therefore, the electric power steering system can determine the human driver's intention to apply torque to the steering system regardless of such limitations.

According to a modified embodiment of the invention, the at least one sensor that provides the sensor information to the control unit for determining the human driver's intention to apply the torque to the steering system includes at least one of an optical camera located in a passenger compartment of the ego vehicle is arranged and at least partially monitors a driver of the ego vehicle, and a hands-on sensor which is provided in/on the steering wheel of the ego vehicle. The optical camera may be arranged to monitor a body/chest of the human driver, e.g. to determine a position of the body/chest of the human driver. A body/chest displaced from the “normal” position when driving may indicate an unintentional application of torque by a human driver to the steering system, e.g. if the hands gripping the steering wheel follow a movement of the body/chest. The optical camera may be arranged to monitor the hands of the human driver, for example to determine a position of the hands. When the hands are positioned on the steering wheel, it may indicate the human driver's intention to apply torque to the steering. The same applies if the hand sensor detects that the human driver's hands are positioned on the steering wheel. The optical camera may be arranged to monitor the head/face of the human driver, e.g., a direction of gaze, an expression indicating fatigue or a medical problem, an abnormal position of the head, e.g. when the driver bends over, to grab an object or determine something else. The optical camera can be arranged so that it monitors in particular the eyes of the human driver, for example to determine a direction of gaze, an eye movement that indicates, for example, fatigue or a medical problem, or something else. In addition, the optical camera can be set up to monitor other occupants of the ego vehicle. For example, if the human driver is talking to the other occupants, this may indicate that he/she is not concentrating on driving the ego vehicle, and the torque applied to the steering system by the human driver is considered not to have been applied intentionally.

According to a modified embodiment of the invention, the control unit receives the torque requested by a steering assistance system that provides the at least one steering assistance function, in particular from a lane centering system or a lane keeping system.

The features and advantages described above in relation to the method according to the invention apply equally to the electric power steering system according to the invention as well as to the steering assistance system according to the invention and vice versa.

These and further aspects of the invention can be seen from the embodiments described below and are clarified by them. Individual features disclosed in the embodiments may, alone or in combination, constitute an aspect of the present invention. Features of the various embodiments can be converted from one embodiment to another embodiment.

• 1 zeigt eine schematische Ansicht eines Ego-Fahrzeugs mit einem Lenkunterstützungssystem umfassend Umgebungssensoren und eine Steuerungsvorrichtung gemäß einer ersten, bevorzugten Ausführungsform,
• 2 zeigt ein elektrisches Servolenksystem zur Bestimmung eines in einem Lenksystem des Ego-Fahrzeugs der 1 anzulegenden Drehmoments gemäß der ersten Ausführungsform, das eine Steuereinheit und eine Antriebseinheit umfasst,
• 3 zeigt eine Draufsicht auf das Ego-Fahrzeug, das sich entlang eines Fahrwegs in der Mitte einer Fahrspur zwischen Fahrspurgrenzen bewegt, zusammen mit einem Schlagloch vor dem Ego-Fahrzeug und einem alternativen Fahrweg, der das Schlagloch vermeidet,
• 4 zeigt ein erstes Beispiel eines Verfahrens zum Bestimmen eines Drehmoments, das in dem elektrischen Servolenksystem aus 2 eines Lenksystems des Ego-Fahrzeugs aus 1 angelegt werden soll, wobei ein menschlicher Fahrer des Ego-Fahrzeugs absichtlich ein Drehmoment auf das Lenksystem aufbringt, was dazu führt, dass das Anlegen des von dem Lenkunterstützungssystem angeforderten Drehmoments als Drehmoment in dem elektrische Servolenksystem übersteuert wird,
• 5 zeigt ein zweites Beispiel eines Verfahren zum Bestimmen eines Drehmoments, das in dem elektrischen Servolenksystem aus 2 eines Lenksystems des Ego-Fahrzeugs aus 1 angelegt werden soll, wobei ein menschlicher Fahrer des Ego-Fahrzeugs unbeabsichtigt ein Drehmoment auf das Lenksystem aufbringt, was dazu führt, dass das von dem Lenkunterstützungssystem angeforderte Drehmoment kontinuierlich als Drehmoment in dem elektrischen Servolenksystem angelegt wird,
• 6 zeigt ein drittes Beispiel eines Verfahrens zum Bestimmen eines Drehmoments, das in dem elektrischen Servolenksystem aus 2 eines Lenksystems des Ego-Fahrzeugs aus 1 angelegt werden soll, wobei ein menschlicher Fahrer des Ego-Fahrzeugs absichtlich ein Drehmoment auf das Lenksystem aufbringt, was dazu führt, dass das in dem elektrischen Servolenksystem anzulegende Drehmoment als das von dem Lenkunterstützungssystem angeforderte Drehmoment bestimmt wird, das um einen Faktor basierend auf dem Absichtsniveau und des von dem menschlichen Fahrer angelegten Drehmoments reduziert wird, und
• 7 zeigt ein Ablaufdiagramm eines Verfahrens zum Bestimmen eines Drehmoments, das in das elektrische Servolenksystem aus 2 eines Lenksystems des Ego-Fahrzeugs aus 1 mit der Lenkunterstützungsfunktion, die auf das elektrische Servolenksystem wirkt, angelegt wird.

In the drawing:

• 1 shows a schematic view of an ego vehicle with a steering support system comprising environmental sensors and a control device according to a first, preferred embodiment,
• 2 shows an electric power steering system for determining a steering system in the ego vehicle 1 torque to be applied according to the first embodiment, which comprises a control unit and a drive unit,
• 3 shows a top view of the ego vehicle moving along a path in the middle of a lane between lane boundaries, along with a pothole in front of the ego vehicle and an alternative path that avoids the pothole,
• 4 shows a first example of a method for determining a torque in the electric power steering system 2 a steering system of the ego vehicle 1 to be applied, wherein a human driver of the ego vehicle intentionally applies torque to the steering system, resulting in the application of the torque requested by the steering assistance system being overridden as torque in the electric power steering system,
• 5 shows a second example of a method for determining torque in the electric power steering system 2 a steering system of the ego vehicle 1 to be applied, wherein a human driver of the ego vehicle inadvertently applies torque to the steering system, resulting in the torque requested by the steering assistance system being continuously applied as torque in the electric power steering system,
• 6 shows a third example of a method for determining a torque in the electric power steering system 2 a steering system of the ego vehicle 1 to be applied, wherein a human driver of the ego vehicle intentionally applies torque to the steering system, resulting in the torque to be applied in the electric power steering system being determined as the torque requested by the steering assist system, which is increased by a factor based on the intention level and the torque applied by the human driver is reduced, and
• 7 shows a flowchart of a method for determining a torque applied to the electric power steering system 2 a steering system of the ego vehicle 1 with the steering support function, which acts on the electric power steering system.

1 shows an ego vehicle 10 with a steering support system 12 according to a first, preferred embodiment. The ego vehicle 10 may be any type of vehicle, including cars, buses, vans, trucks, and others.

The steering support system 12 of the first embodiment realizes a steering support function (SAF), which is, for example, a lane centering system (LCS). In an alternative embodiment, the steering assistance system 12 is a lane keeping system (LKS). The steering support system 12 therefore supports a human driver of the ego vehicle 10 in keeping the ego vehicle 10 in the middle of a respective lane.

The steering assistance system 12 includes environmental sensors 14, 16 for monitoring an environment 18 of the ego vehicle 10. Specifically, the steering assistance system 12 of the first embodiment includes a front LiDAR-based environmental sensor 14, hereinafter referred to as a front LiDAR, and an optical camera 16, which is directed towards a front of the ego vehicle 10. Therefore, when driving forward, as indicated by the forward direction of travel 20, the front LiDAR 14 and the optical camera 16 monitor the environment 18 of the ego vehicle 10 in the direction of travel 20 in front of the ego vehicle 10. Each of the environment sensors 14, 16 generates sensor information, which can consist of raw data or pre-processed data. In an alternative embodiment, the steering assistance system 12 may include various environmental sensors 14, 16, including any single environmental sensor 14, 16 or any combination of environmental sensors 14, 16 of the same or different type from the front LiDAR-based environmental sensor 14 located to the front of the Ego vehicle 10 directional optical camera 16 and a front side radar sensor.

The ego vehicle 10 of the first embodiment further comprises a control device 22 and a data connection 24, which connects the environmental sensors 14, 16 and the control device 22 to one another. The control device 22 can be any type of control device 22 that is suitable for use in the ego vehicle 10. Such control devices 22 are typically known as ECUs (electronic control units) in the automotive sector. The control device 22 can be shared to perform multiple tasks or applications. The control device 22 receives the sensor information from the environmental sensors 14, 16 and processes the received sensor information as described below. The sensor information may be provided by the environmental sensors 14, 16 of the ego vehicle 10 in any suitable manner and format. The sensor information can be preprocessed or raw sensor data.

The data connection 24 may be a dedicated connection between the environmental sensors 14, 16 and the control device 22 or a data bus. In addition, the data connection 24 may be a shared data connection 24 that is used by various types of devices of the ego vehicle 10, for example a general-purpose data bus. The data connection 24 can be implemented, for example, as a CAN bus, LIN bus or something else. The data connection 24 may be a single data connection 24 that connects the environmental sensors 14, 16 and the control device 22. Although in 1 a single data connection 24 is shown, several data connections 24 or data buses can also be provided in parallel to connect the environmental sensors 14, 16 to the control device 22. In this case, the multiple data connections 24 or data buses can be viewed together as a data connection 24.

The sensor information from the environmental sensors 14, 16 is transmitted to the control device 22 via the data connection 24. Although in 1 a single control device 22 is shown, several individual devices can be provided, which together realize the control device 22.

The ego vehicle 10 further includes an electric power steering system 26 for determining a torque to be applied in a steering system 28 of the ego vehicle 10. The electric power steering system 26 is sometimes also referred to as a motor-driven power steering system (MDPS). The steering assist system 12 is connected to the electric power steering system 26 and acts on the electric power steering system 26 to exert torque on the steering system 28. The electric power steering system 26 not only determines the torque, but also transmits it to the steering system 28. The electric power steering system 26 is in 2 shown together with the steering system 28.

Accordingly, the electric power steering system 26 includes a control unit 30 for determining the torque to be applied in the steering system 28. The control unit 30 can be any control unit 30 that is suitable for use in the ego vehicle 10. The control unit 30 is connected to the control device 22 of the steering support system 12 via the data connection 24 in a manner not shown in the figures.

The electric power steering system 26 further includes a drive unit 32, which is connected to the control unit 30 via a control connection 34. The control unit 30 controls the drive unit 32 via the control connection 34, which can be any analog or digital connection, to apply the determined torque in the steering system 28. The drive unit 32 therefore includes an electrically driven motor which applies a drive current based on the control signals received from the control unit 30. In this way, the drive unit 32 applies the torque determined by the control unit 30 to the steering system 28.

The steering system 28 includes a steering wheel 36, a steering column 38 and a steering gear, not shown in the figures, which establishes a steering connection between the steering column 38 and the front wheels of the ego vehicle 10. The steering column 38 is rotatably mounted with bearings 40. The steering column 38 can be rotated according to the direction of rotation 42 by the drive unit 32, which is connected to the steering column 38 of the steering system 28 and exerts the torque on the steering column 38.

The electric power steering system 26 further includes an internal optical camera 44 as a sensor for providing sensor information, as will be explained in more detail below. The optical interior camera 44 is arranged in a passenger compartment of the ego vehicle 10. The inner optical camera 44 is connected to the control unit 30 via the data connection 24. In an alternative embodiment, the internal optical camera 44 is provided separately from the power steering system 26 for use by different systems of the ego vehicle 10.

The steering assist system 12 and the electric power steering system 26 are provided separately from each other according to the first embodiment. In an alternative embodiment, the steering assist system 12 and the electric power steering system 26 may be integrally implemented into the ego vehicle 10.

7 shows a flowchart of a method for determining a torque to be applied in the electric power steering system 26 of the steering system 28 of the ego vehicle 10, the steering support system 12 acting on the electric power steering system 26 according to the first embodiment. The method is carried out with the ego vehicle 10 including the steering support system 12, the steering system 28 and in particular the electric power steering system 26. The procedure is described with additional reference to 3 explained, which shows the ego vehicle 10 moving along a route 46 in the middle of a lane 48 between lane boundaries 50. 3 also shows a pothole 52 in the forward direction of travel 20 in front of the ego vehicle 10 and an alternative route 54 that bypasses the pothole 52.

The method begins in step S100 with receipt of a requested torque from the steering assistance system 12.

For this purpose, the control device 22 of the driving support system 12 receives sensor information from the front LiDAR 14 and the optical camera 16 and determines the route 46 for driving in a center of the lane 48, as in 3 you can see. The steering support system 12 determines a torque to be applied in the steering system 28 and sends the corresponding request to the electric power steering system 26 in order to influence the travel path 46 of the ego vehicle 10. The steering support system 12 is permanently active in a current driving state and demands torque permanently on the electric power steering system 26.

The control unit 30 receives the requested torque from the electric power steering system 26.

Step S110 involves determining a torque applied to the steering system 28 by a human driver.

The torque applied by the human driver to the steering system 28 can be determined in different ways, for example with the help of a corresponding torque sensor or, for example, based on an electrical power that is required by the drive unit 32 to apply a torque. The control device 30 thus receives information regarding the torque applied by the human driver to the steering system 28 from the respective sensors or, for example, as feedback information from the drive unit 32.

Step S120 involves determining an intention of the human driver to apply the torque to the steering system 28.

The human driver's intention to apply torque to the steering system 28 is determined based on behavior of the human driver, which may be intentional behavior, such as the human driver attempting to pick up an object from the passenger compartment floor, or unintentional Behavior, for example in the event of fatigue or a medical problem such as a heart attack or other. The human driver's intention to apply torque to the steering system 28 is therefore generally based on the driver being focused on driving and actively and intentionally applying the torque. If the human driver of the ego vehicle is disturbed, distracted or in another state that does not allow the torque to be applied intentionally, the driving support system 12 safely follows the predetermined path 46, he/she has no intention of applying the torque to apply the steering system 28.

Therefore, the electric power steering 26 receives camera images as sensor information provided by the inner optical camera 44 as a sensor to at least partially monitor a human driver of the ego vehicle 10. The internal optical camera 44 may be arranged to monitor a body/chest of the human driver, e.g., to determine a position of the body/chest of the human driver. A body/chest moving from the “normal” driving position may indicate an inadvertent application of torque by a human driver to the steering system 28, e.g. if the hands gripping the steering wheel 36 follow movement of the body/chest. The internal optical camera 44 may be arranged to monitor the hands of the human driver, for example to determine a position of the hands. When the hands are positioned on the steering wheel 36, this may indicate an intention by the human driver to apply torque to the steering system 28. The internal optical camera 44 may be arranged to monitor a head/face of the human driver, e.g., a direction of gaze, a facial expression indicative of fatigue or a medical problem, an abnormal position of the head, e.g., when the driver is moving bends down to grab an object or determine something else. The internal optical camera 44 may be arranged to specifically monitor the eyes of the human driver, for example to determine a direction of gaze, an eye movement indicating, for example, fatigue or a medical problem, or others. In addition, the internal optical camera 44 may be arranged to monitor other occupants of the ego vehicle 10. For example, if the human driver is conversing with the other occupants, this may indicate that he/she is not concentrating on driving the ego vehicle 10, and the torque applied to the steering system 28 by the human driver is considered not to have been applied intentionally . Even if the human driver checks his cell phone or even uses the vehicle's infotainment system (GPS, radio, etc.), this may indicate that he is not concentrating on driving the ego vehicle 10 and that of the human driver is on the steering system 28 applied torque is considered not to have been applied intentionally. Any of the above actions may be performed alone or in combination to monitor the human driver and determine the human driver's intention to apply torque to the steering system 28.

In particular, as mentioned in part above, the information regarding the human driver of the ego vehicle may be processed to determine the human driver's intention to apply the torque to the steering system 28 based on at least one of the following: Detection the driver's hands positioned on the steering wheel 36, detecting a distraction/attention of the driver when driving the ego vehicle 10, detecting drowsiness and / or tiredness of the driver of the ego vehicle 10, a Detecting a state of health of the driver of the ego vehicle 10, detecting a glare of the driver of the ego vehicle 10 and detecting that the driver of the ego vehicle 10 is actively making a telephone conversation, is actively using a mobile device and / or is actively using any device of the ego vehicle 10, for example an entertainment system. If the human driver's hands are positioned on the steering wheel 36, it can be assumed that the human driver is paying attention and is therefore only intentionally applying torque to the steering system 28. Distraction and lack of attention may indicate a lack of intention to apply torque to the steering system 28, for example, when the human driver is making movements due to other activities and is applying torque to the steering system 28 due to such movement. Tiredness or fatigue typically indicates, or at least increases the likelihood, that a human is not acting intentionally, that is, does not intend to apply the torque to the steering system 28. Depending on the medical condition, the human driver may be unable to intentionally apply torque to the steering system 28, for example in the event of unconsciousness or death. Driver glare can occur from sunlight and/or lights from oncoming vehicles. This can be recognized, for example, based on certain movements of the human driver, such as squinting the eyes or others, which makes it difficult for the human driver of the ego vehicle 10 to intentionally steer the ego vehicle 10 and thus intentionally apply the torque to the steering system 28 . Using cell phones or other mobile devices while driving the ego vehicle 10 is also a typical sign that the human driver is not paying attention. Consequently, the human driver will not intentionally apply torque to the steering system 28.

The control unit 30 receives the information regarding an intention of the human driver to apply the torque to the steering system 28 and determines the human driver's intention to apply the torque to the steering system 28 as a quantified intention level, particularly between a minimum intention and a maximum intention , based on the above criteria.

Step S130 involves determining the torque to be applied in the electric power steering system 26 based on the torque requested by the steering assist device 12, the determined torque applied to the steering system 28 by the human driver, and the human driver's determined intention of the torque to be applied to the steering system 28. The control unit 30 determines the torque to be applied in the steering system 28.

Furthermore, the determined torque is applied by the control unit 30, which controls the drive unit 32 according to the determined torque.

The torque to be applied in the electric power steering system 26 is determined by binary the torque requested by the steering assist system 12 based on the torque applied to the steering system 28 by the human driver and/or the human driver's specific intention to apply the torque to the steering system 28 , is changed gradually or continuously, using the determined intention level as the human driver's intention to apply the torque to the steering system 28. Thus, both the torque applied by the human driver to the steering system 28 and the human driver's intention to apply the torque to the steering system 28 may be used alone or in combination to change the requested torque to the torque to be applied in the electric power steering system 26 to determine.

An override of the torque requested by the SAF steering support system 12 does not occur if the human driver of the ego vehicle 10 does not intentionally apply the torque to the steering system 28. Based on the determination of the human driver's intention to apply the torque to the steering system, unintentional deactivation or override of the steering assistance system 12 or the torque requested by the steering assistance system 12 is prevented. This concerns, for example, the intention level zero and refers to a binary change in the requested torque.

Otherwise, the requested torque may be modified based on one or more of the following parameters: an absolute value of the torque applied to the steering system 28 by the human driver, a difference between the requested torque and the torque applied to the steering system 28 by the human driver, an intention level Human driver's intention to apply torque to the steering system 28, or derivatives thereof, to determine the torque applied in the electric power steering system 26. The modification can be a simple change be between two or more states, e.g. requested torque, various percentages of requested torque and zero, or a calculation based on a mathematical formula such as torque equals requested torque minus torque applied by the human driver.

In particular, determining the torque to be applied in the electric power steering system 26 additionally includes one or more of the following options from providing modified limit values for the torque to be requested from the steering assistance system 12, i.e. saturation of the steering torque, determining the torque to be applied by scaling the at least one Steering assistance function requested torque with a factor, changing an algorithm responsible for determining the torque to be applied based on the torque applied by the human driver in the steering system 28, changing feedback controller parameters in a feedback controller for determining the torque to be applied in the electrical power steering system 26 and changing a deactivation condition based on human driver override to deactivate the application of torque in the electric power steering system 26. Some of the above options may be applied to adaptively "resist" the steering wheel 36 to driver steering to change, i.e. a torque that must be exerted by the human driver of the ego vehicle 10 in order to be able to move the steering wheel 36 and steer the ego vehicle 10 as desired. Some of the above options may be applied to enable adaptive changes in conditions that result in deactivation of the electric power steering system 26, i.e., at least temporarily, no torque is applied to the electric power steering system 26.

The above-mentioned limits for the torque to be requested by the steering assistance system 12 can be changed in the respective steering assistance function or in the electric power steering system 26 or in both. Scaling the torque requested by the steering assistance system 12 by a factor involves determining the torque to be applied in the electric power steering system 26 with a torque value that is calculated using the requested torque as a starting point and modifying this torque value by the factor, in particular depending on that torque applied by the human driver to the steering system 28 and/or the human driver's level of intent to apply the torque to the steering system 28. The feedback controller enables appropriate feedback control to smooth the torque to be applied in the electric power steering system 26. The deactivation condition for deactivating torque application in the electric power steering system 26 may be changed to be more stringent to prevent deactivation or less strict to allow rapid deactivation. These options can be used individually or in any suitable combination.

Step S140 involves generating a warning to the human driver when a discrepancy is detected between the torque applied by the human driver to the steering system 28 and the human driver's specific intention to apply the torque to the steering system 28.

The discrepancy between the torque applied to the steering system 28 by the human driver and the human driver's specific intention to apply the torque to the steering system 28 relates to a situation in which the human driver inadvertently applies the torque to the steering system 28, as described above Explained in detail. The warning can be an acoustic and/or visual warning that can be generated via any user interface device of the ego vehicle 10.

Below are three possible applications of the above method using the 4 until 6 discussed.

4 concerns a first example and shows different torque curves in the upper diagram. First, a torque 56 requested by the steering assistance system 12 is shown, which runs together with the torque 60 determined by the electric power steering system 26 until the time t _d is reached. The driving support system 12 therefore actively steers the ego vehicle 10 so that it follows the in 3 route 46 shown follows. 4 also shows the torque 58 applied by the human driver of the ego vehicle 10. The torque 58 applied by the human driver is low up to time t ₁ , which refers to a phase 62 without torque 58 applied by the human driver. The human driver therefore holds the steering wheel 36, but does not actively attempt to apply torque to the steering system 28 via the steering wheel 36.

However, the torque 58 applied by the human driver decreases from time t ₁ to, as the human driver begins to actively apply the torque 58 to the steering system 28 via the steering wheel 36. In this example, it is assumed that the human driver intentionally wants to take the alternative route 54, for example due to the pothole 52 in the lane 48.

The control unit 30 processes the torque 56 requested by the steering assistance system 12, the torque 58 applied by the human driver, and the camera images received from the internal optical camera 44. The control unit 30 determines the human driver's level of intent to apply the torque 58 to the steering system 28. If the control unit 30 receives information about externally detected objects/obstacles such as potholes 52, parked vehicles or others that are in the environment 18 of the ego vehicle 10, the control unit 30 may process this information to check/confirm whether the human driver's determined intention to apply torque to the steering system matches the information about the external environment.

The control unit 30 determines the torque 60 to be applied in the electric power steering system 26 as the torque 56 requested by the steering assistance system 12 until the time t _d is reached. At time t _d, the control unit 30 overrides the torque 56 requested by the steering assistance system 12 and sets the torque 60 to be applied in the electric power steering system 26 as zero, so that only the torque 58 applied by the human driver acts on the steering system 28. The time t _d depends on different conditions and may vary over time for different situations based on the torque 58 applied by the human driver and the respective level of intent. In this example, the intention level reaches its maximum at time t _d .

Due to the torque 58 applied by the human driver and the override of the torque 56 requested by the driving support system 12, the ego vehicle 10 deviates from the travel path 46 determined by the driving support system 12. The bottom diagram of the 4 shows a position error 66, which represents a difference between the route 46 determined by the driving support system 12 and the alternative route 54, which is followed based on the intervention of the human driver.

At time t ₂ the human driver stops actively applying the torque 58 to the steering system 28 via the steering wheel 36; he merely holds the steering wheel 36. In the example 4 However, the override of the torque 56 requested by the steering assistance system 12 continues after time t ₂ when the human driver stops actively applying the torque 58 to the steering system 28. In another example, the oversteer ends at time t ₂ and the control unit 30 returns to determine the torque 60 to be applied in the electric power steering system 26 as the torque 56 requested by the steering assist system 12 to reduce the position error 66.

5 concerns a second example and shows different torque curves in the diagram above. First, a torque 56 requested by the steering assistance system 12 is shown, which converges with the torque 60 determined by the electric power steering system 26. The driving support system 12 therefore actively steers the ego vehicle 10 so that it follows the in 3 route 46 shown follows. 5 also shows the torque 58 applied by the human driver of the ego vehicle 10. The torque 58 applied by the human driver is low up to time t ₁ , which refers to a phase 62 without torque 58 applied by the human driver. The human driver therefore holds the steering wheel 36, but does not actively attempt to apply torque to the steering system 28 via the steering wheel 36.

The torque 58 applied by the human driver increases from time t ₁ as the human driver begins to actively exert the torque 58 on the steering system 28 via the steering wheel 36. This example assumes that the human driver applies the torque unintentionally.

The control unit 30 processes the torque 56 requested by the steering assistance system 12, the torque 58 applied by the human driver, and the camera images received from the internal optical camera 44. The control unit 30 determines the human driver's level of intent to apply the torque 58 to the steering system 28. In this example, the intent level is low between times t ₁ and t ₂ . On this basis, the control unit 30 determines the torque 60 to be applied in the electric power steering system 26 as the torque 56 requested by the steering assistance system 12. The torque 60 to be applied in the electric power steering system 26 is continuously determined as the torque 56 requested by the steering assistance system 12, since the torque 56 requested by the human Driver applied torque 58 along with the intention level indicates that the human driver does not want to apply the torque 58 to the steering system 28.

Based on the torque 58 applied by the human driver and the torque 56 requested by the steering assistance system 12, which is the torque 60 to be applied in the electric power steering system 26, the ego vehicle 10 deviates from the travel path 46 in accordance with that in the lower part of 5 specified position error 66. Since the torque 56 requested by the steering assistance system 12 is the torque 60 to be applied in the electric power steering system 26, the steering assistance system 12 continues to act on the electric power steering system 26 to keep the ego vehicle 10 in the center of the lane 48. When the human driver stops applying the torque 58 to the steering system 28, the torque 56 requested by the driving support system 12 allows the position error 66 to be reduced and the ego vehicle 10 returns to the path 46.

6 concerns a third example and shows different torque curves. First, a torque 56 requested by the steering assistance system 12 is shown, which converges with the torque 60 determined by the electric power steering system 26. The driving support system 12 therefore actively steers the ego vehicle 10 so that it follows the in 3 route 46 shown follows. 6 also shows the torque 58 applied by the human driver of the ego vehicle 10. The torque 58 applied by the human driver is low up to time t ₁ , which refers to a phase 62 without torque 58 applied by the human driver. The human driver therefore holds the steering wheel 36, but does not actively attempt to apply torque to the steering system 28 via the steering wheel 36.

The torque 58 applied by the human driver increases from time t ₁ since the human driver begins to actively apply the torque 58 to the steering system 28 via the steering wheel 36. This example assumes that the human driver is applying the torque intentionally.

The control unit 30 processes the torque 56 requested by the steering assistance system 12, the torque 58 applied by the human driver, and the camera images received from the internal optical camera 44. The control unit 30 determines the human driver's level of intent to apply the torque 58 to the steering system 28. In this example, the intent level is high between times t ₁ and t ₂ . Based on this, the control unit 30 determines the torque 60 to be applied in the electric power steering system 26 as the torque 56 requested by the steering assist system 12, which is reduced according to a factor based on the intention level and the torque 58 applied by the human driver. Therefore, the torque to be applied in the electric power steering system 26 is 60 compared to the second example 5 reduced.

Reference symbol list

10

Ego vehicle

12

Steering support system

14

front LiDAR, environmental sensor

16

optical camera, environmental sensor

18

Vicinity

20

Forward direction of travel

22

Control device

24

Data Connection

26

electric power steering system

28

Steering system

30

Control unit

32

Drive unit

34

Control connection

36

steering wheel

38

Steering column

40

camp

42

Direction of rotation

44

optical camera, sensor

46

route

48

lane

50

Lane delimitation

52

pothole

54

alternative route

56

Torque requested by the steering assistance system

58

Torque applied by the human driver

60

Specific torque

62

Phase without torque applied by the human driver

64

Phase with torque applied by the human driver

66

Position error

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 20150012182 A1 [0010]
• US 20160152233 A1 [0011]
• US 20180072310 A1 [0011]
• US 20190315403 A1 [0012]

Claims (13)

Method for determining a torque to be applied in an electric power steering system (26) of a steering system (28) of an ego vehicle (10) with at least one steering support function acting on the electric power steering system (26), comprising the steps Receiving a torque requested by the at least one steering assistance function, Determining a torque applied to the steering system (28) by a human driver, Determining an intention of the human driver to apply the torque to the steering system (28), and Determining the torque to be applied in the electric power steering system (26) based on the torque requested by the at least one steering assistance function, the determined torque applied to the steering system (28) by a human driver, and the human driver's determined intention of the torque to be applied to the steering system (28). Procedure according to Claim 1 , characterized in that the step of determining a human driver's intention to apply the torque to the steering system (28) includes determining the human driver's intention to apply the torque to the steering system (28) based on a received from a driver monitoring system Input includes. Procedure according to one of the Claims 1 or 2 , characterized in that the step of determining an intention of the human driver to apply the torque to the steering system (28) comprises determining the intention of the human driver to apply the torque to the steering system (28) based on one of - Detection of the driver's hands positioned on the steering wheel (36), - detection of a distraction/attention of the driver when driving the ego vehicle (10), - detection of drowsiness and/or tiredness of the driver of the ego vehicle (10), - detection a state of health of the driver of the ego vehicle (10), - recognizing that the driver of the ego vehicle (10) is dazzled, - recognizing that the driver of the ego vehicle (10) is actively making a telephone conversation, is actively using a mobile device and / or actively uses any device of the ego vehicle (10), for example an entertainment system, and - detecting an environment (18) of the ego vehicle (10), in particular with regard to the presence of potholes (52), parked cars or any type of obstacle or other object, in particular to validate the human driver's determined intention to apply torque to the steering system (28). Method according to one of the preceding claims, characterized in that the step of determining an intention of the human driver to apply the torque to the steering system (28) is determining the intention of the human driver to apply the torque to the steering system (28). quantified intention level, in particular between a minimum intention and a maximum intention, and the step of determining the torque to be applied in the electric power steering system (26) based on the torque requested by the at least one steering assistance function, the determined torque required by a human driver is applied to the steering system (28), and the human driver's specific intention to apply the torque to the steering system (28), determining the torque to be applied in the electric power steering system (26) based on the torque requested by the at least one steering assistance function, the particular torque applied to the steering system (28) by a human driver and the particular level of intent. Method according to one of the preceding claims, characterized in that the step of determining the torque to be applied in the electric power steering system (26) based on the torque requested by the at least one steering assistance function, the determined torque applied by a human driver to the steering system (28 ) is applied, and the human driver's specific intention to apply the torque to the steering system (28), determining the torque to be applied in the electric power steering system (26) by modifying the torque requested by the at least one steering assistance function in a binary, stepwise manner or continuously based on the determined torque applied to the steering system (28) by the human driver and/or the human driver's determined intention to apply the torque to the steering system (28). Method according to one of the preceding claims, characterized in that the step of determining the in the electrical Torque to be applied to the power steering system (26) based on the torque requested by the at least one steering assistance function, the specific torque applied to the steering system (28) by a human driver, and the human driver's specific intention to apply the torque to the steering system (28 ) to apply, at least one comprises - providing modified limits for the torque to be requested by the at least one steering support function, ie a saturation of the steering torque, - determining the torque to be applied by scaling the torque requested by the at least one steering support function with a factor, - changing a Algorithm responsible for determining the torque to be applied based on the torque applied to the steering system (28) by the human driver, - changing feedback control parameters in a feedback controller for determining the torque to be applied in the electric power steering system (26), and - changing a deactivation condition based on override by the human driver for deactivating the application of torque in the electric power steering system (26). A method according to any one of the preceding claims, characterized in that the method comprises a step of generating a warning to the human driver when there is a discrepancy between the torque applied by the human driver to the steering system (28) and the human driver's particular intention to do so Applying torque to the steering system (28) is determined. Electric power steering system (26) for determining a torque to be applied in a steering system (28) of an ego vehicle (10), comprising at least one steering support function acting on the electric power steering system (26). a control unit (30) and a drive unit (32) controlled by the control unit (30) to apply the determined torque in the steering system (28), wherein the control unit (30) receives a torque requested by the at least one steering assistance function, the control unit (30) receives information about a torque applied to the steering system (28) by a human driver, the control unit (30) receives information about an intention of the human driver to apply the torque to the steering system (28), and the control unit (30) determines the torque to be applied in the steering system (28) by controlling the drive unit (32) based on the torque requested by the at least one steering assistance function, the specific torque applied to the steering system (28) by a human driver is applied, and the human driver's specific intention to apply the torque to the steering system (28). Electric power steering system (26). Claim 8 , characterized in that the electric power steering system (28) includes at least one sensor (44) that provides sensor information to the control unit (30) for determining the human driver's intention to apply the torque to the steering system (28). Electric power steering system (26). Claim 9 , characterized in that the at least one sensor (44), which provides the sensor information for determining the human driver's intention to apply the torque to the steering system (28) to the control unit (30), comprises at least one of - an optical camera (44), which is arranged in a passenger compartment of the ego vehicle (10) and at least partially monitors a driver of the ego vehicle (10), and - a hands-on sensor which is in/on the steering wheel (36) of the ego -Vehicle (10) is provided. Electric power steering system (26) according to one of the Claims 8 until 10 , characterized in that the electric power steering system (26) includes a driver monitoring system that determines the information about the human driver's intention to apply the torque to the steering system (28) and provides the information to the control unit (30). Electric power steering system (26) according to one of the Claims 8 until 11 , characterized in that the control unit (30) receives the torque requested by a steering assistance system (12) which provides the at least one steering assistance function, in particular from a lane centering system or a lane keeping system. Steering support system (12), in particular as a lane centering system or lane keeping system, comprising the electric power steering system (26) according to one of Claims 8 until 12 .

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