SE542588C2

SE542588C2 - Method and control device for controlling steering of a vehicle

Info

Publication number: SE542588C2
Application number: SE1851267A
Authority: SE
Inventors: Malte Rothhämel
Original assignee: Scania Cv Ab
Priority date: 2018-10-17
Filing date: 2018-10-17
Publication date: 2020-06-09
Also published as: DE102019006537B4; DE102019006537A1; DE102019006537A8; SE1851267A1

Abstract

The present invention relates to a method performed by a control device (100) for controlling steering of a vehicle (V). The vehicle (V) has a main steering control arrangement (A1) for automatically controlling steering of the vehicle and at least one auxiliary steering control arrangement (A2) as backup for the main steering control arrangement (A1). The method comprises the steps of: determining (S1) the probability of the main steering control arrangement (A1) malfunctioning; and activating an auxiliary steering control arrangement (A2) based on the thus determined probability of the main steering control arrangement (A1) malfunctioning.The present invention also relates to a control device for controlling steering of a vehicle. The present invention also relates to a computer program and a computer readable medium.

Description

|\/IETHOD AND CONTROL DEVICE FOR CONTROLLING STEERING OF AVEHICLE TECHNICAL FIELD The invention relates to a method performed by a control device for controllingsteering of a vehicle. The invention also relates to a control device forcontrolling steering of a vehicle. The invention also relates to a vehicle. Theinvention in addition relates to a computer program and a computer readable medium.

BACKG ROUND ART There is a lot of development around piloted and autonomous vehicles. Forsuch vehicles safety is a key issue. One safety issue is controlling steering ofsuch vehicles. ln order to improve safety with regard to steering such vehiclethe vehicle may be provided with an auxiliary steering control arrangement asa backup to its main steering control arrangement. Such an auxiliary steeringcontrol arrangement may, for a vehicle such as commercial vehicle in theshape of a truck, be a steer-by-brake steering control arrangement for steeringthe vehicle by means of differential braking. ln order to facilitate safe control of steering for piloted and autonomousvehicles, detection of malfunction of the main steering control arrangementand activation of the auxiliary steering control arrangement needs to beobtained in an efficient way.

There is thus a need for improving controlling steering of a vehicle duringoperation of the vehicle.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method performed by acontrol device for controlling steering of a vehicle, which facilitates reliablecontrol of main and auxiliary steering control arrangement for safe steering ofthe vehicle.

Another object of the present invention is to provide a control device forcontrolling steering of a vehicle, which facilitates reliable control of main and auxiliary steering control arrangement for safe steering of the vehicle.

Another object of the present invention is to provide a vehicle comprising such a control device.

SUMMARY OF THE INVENTION These and other objects, apparent from the following description, are achievedby a method, a control device, a vehicle, a computer program and a computerreadable medium, as set out in the appended independent claims. Preferredembodiments of the method and the control device are defined in appended dependent claims.

Specifically an object of the invention is achieved by a method performed by acontrol device for controlling steering of a vehicle. Said vehicle has a mainsteering control arrangement for automatically controlling steering of thevehicle and at least one auxiliary steering control arrangement as backup forthe main steering control arrangement. The method comprises the steps of:determining the probability of the main steering control arrangementmalfunctioning; and activating an auxiliary steering control arrangement basedon the thus determined probability of the main steering control arrangement malfunctioning.

Hereby reliable control of main and auxiliary steering control arrangement forsafe steering of the vehicle is facilitated. By thus determining the probability ofthe main steering control arrangement malfunctioning, safety is improved inthat an indication of malfunctioning may be obtained before a malfunctionactually has been detected, which facilitates taking actions such as activatingan auxiliary steering control arrangement earlier. This facilitates reducing timeneeded for activating such auxiliary steering control arrangement when actualmalfunction of the main steering control arrangement has been detected.

According to an embodiment of the method the step of activating an auxiliarysteering control arrangement based on the thus determined probability of themain steering control arrangement malfunctioning comprises activating anauxiliary steering control arrangement if the thus determined probabilityexceeds a predetermined threshold value. Hereby reliable control of main andauxiliary steering control arrangement for safe steering of the vehicle isfacilitated. By thus activating an auxiliary steering control arrangement only ifa predetermined threshold value for the probability of the main steering controlarrangement malfunctioning is exceeded more efficient control of the steeringis obtained in that unnecessary activation of an auxiliary steering controlarrangement may be avoided.

According to an embodiment of the method the step of determining theprobability of the main steering control arrangement malfunctioning isperformed based on one or more of: the trajectory of the vehicle relative to thetrajectory of the route along which the vehicle is travelling; historical dataregarding malfunctioning; current weather conditions; current road conditions;and determined abnormal behaviour associated with the main steering controlarrangement. Hereby the probability of the main steering control arrangement malfunctioning may be determined in an efficient and reliable way.

According to an embodiment of the method the step of determining theprobability of the main steering control arrangement malfunctioning comprisesthe step of determining kind of malfunction. By thus determining kind of malfunction a basis for steering control of the vehicle comprising basis foractivation of auxiliary steering control arrangement is obtained.

According to an embodiment of the method the predetermined threshold value depends on the kind of malfunction. Herby efficient steering control is obtained.

According to an embodiment the method, when an auxiliary steering controlarrangement has been activated, comprises the step of determining whetherthe main steering control arrangement and/or auxiliary steering controlarrangement síggzglqare-tebe remaineel activated or be deactivated based onone or more of: whether the main steering control arrangement is determinedto actually malfunction; and kind of malfunction of the main steering controlarrangement. Herby reliability and safety of steering control of the vehicle maybe further improved. Herby efficiency of steering control may be further improved.

Specifically an object of the invention is achieved by a control device forcontrolling steering of a vehicle. Said vehicle has a main steering controlarrangement for automatically controlling steering of the vehicle and at leastone auxiliary steering control arrangement as backup for the main steeringcontrol arrangement. The control device is configured to: determine theprobability of the main steering control arrangement malfunctioning; andactivate an auxiliary steering control arrangement based on the thusdetermined probability of the main control steering arrangement malfunctioning.

According to an embodiment the control device is configured to activate anauxiliary steering control arrangement if the thus determined probability exceeds a predetermined threshold value.

According to an embodiment the control device is configured to determine theprobability of the main steering control arrangement malfunctioning based onone or more of: the trajectory of the vehicle relative to the trajectory of the route along which the vehicle is travelling; historical data regarding malfunctioning; current weather conditions; current road conditions; and determined abnormal behaviour associated with the main steering control arrangement.

According to an embodiment the control device, when determining theprobability of the main steering control arrangement malfunctioning, isconfigured to determine kind of malfunction.

According to an embodiment of the control device the predetermined thresholdvalue depends on the kind of malfunction.

According to an embodiment the control device, when an auxiliary steeringcontrol arrangement has been activated, is configured to determine whetherthe main steering control arrangement and/or auxiliary steering controlarrangement gilgyjgareäebe remaineei activated or be deactivated based onone or more of: whether the main steering control arrangement is determinedto actually malfunction; and kind of malfunction of the main steering control arrangement.

Specifically an object of the invention is achieved by a vehicle comprising acontrol device as set out herein.

Specifically an object of the invention is achieved by a computer program forcontrolling steering of a vehicle, said computer program comprising programcode which, when run on an electronic control unit or another computerconnected to the electronic control unit, causes the electronic control unit to perform the method steps as set out herein.

Specifically an object of the invention is achieved by a computer readablemedium comprising instructions which, when executed by a computer, cause the computer to carry out the method as set out herein.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention reference is made to thefollowing detailed description when read in conjunction with the accompanyingdrawings, wherein like reference characters refer to like parts throughout the several views, and in which: Fig. 1 schematically illustrates a side view of a vehicle according to anembodiment of the present disclosure; Fig. 2 schematically illustrates a plan view of the vehicle in fig. 1 driving on alane of a road utilizing a control device for controlling steering of the vehicle according to an embodiment of the present disclosure; Fig. 3 schematically illustrates a block diagram of a control device forcontrolling steering of a vehicle according to an embodiment of the presentdisclosure; Fig. 4 schematically illustrates a flowchart of a method performed by a controldevice for controlling steering of a vehicle according to an embodiment of thepresent disclosure; and Fig. 5 schematically illustrates a computer according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter the term "link" refers to a communication link which may be aphysical connector, such as an optoelectronic communication wire, or a non-physical connector such as a wireless connection, for example a radio or microwave link.

Fig. 1 schematically illustrates a side view of a vehicle V according to anembodiment of the present disclosure. The vehicle V is travelling on a road R.The exemplified vehicle V is a commercial vehicle in the shape of a truck. The vehicle V may be any suitable vehicle such as a bus or a car. The vehicle maybe a piloted vehicle, i.e. a vehicle having a driver. The vehicle may be an autonomous vehicle.

The exemplified vehicle may be operated in any suitable way. The exemplifiedvehicle may be operated by means of an internal combustion engine. Theexemplified vehicle may be an electrically operated vehicle. The exemplifiedvehicle may be a hybrid vehicle.

The vehicle according to the present invention may have any suitable numberof wheel axles with wheel. One or more of said wheel axles with wheels maybe drive axle for propelling the wheels of the vehicle. The vehicle according tothe present invention may have one or more front axles, one or more rear axlesoperating as drive axles in combination with non-driving support axlesarranged in front and/or behind driving axel/axles. The vehicle according to thepresent invention may be any wheeled articulated vehicle such as anarticulated bus having certain wheel configuration. The vehicle according tothe present invention may be a vehicle, e.g. truck, having a tractor, where thetractor may be a tractor without trailer or a tractor with one or more trailers.The vehicle according to the present invention may be a vehicle, e.g. truck, having no trailer or one or more trailers.

The vehicle has a main steering control arrangement for automaticallycontrolling steering of the vehicle and at least one auxiliary steering controlarrangement as backup for the main steering control arrangement, see e.g.fig. 2.

The vehicle according to the present invention may have one or more axleswith steerable wheels. The steerable wheels may be steerable by means ofthe main steering control arrangement. The steerable wheels may be steerableby means of a steering wheel. The steerable wheels may be steerable bymeans of the auxiliary steering control arrangement. The vehicle according to the present invention may have wheel axle such as a rear wheel axle with steerable wheels steerable by steering control arrangement separated fromthe steering wheel mechanism actuated by the main steering controlarrangement and/or the steering wheel of the vehicle.

A control device 100 for controlling steering of the vehicle V is provided. Thecontrol device 100 is according to an embodiment comprised in vehicle V. Thevehicle V comprises, according to an embodiment, a control device 100 forcontrolling steering of the vehicle according to fig. 3.

The vehicle V is, according to an embodiment, arranged to be operated inaccordance with a method l\/l1 for controlling steering of the vehicle accordingto fig. 4.

Fig. 2 schematically illustrates a plan view of the vehicle in fig. 1 driving on alane L of a road R utilizing a control device 100 for controlling steering of the vehicle according to an embodiment of the present disclosure.

Fig. 2 illustrates a curve portion of the road R, the vehicle V driving on the laneL in that curved portion.

The vehicle V may comprise a control device 100 for controlling steering of a vehicle V during operation of the vehicle V.

The vehicle V comprises, according to an embodiment, a control device 100for controlling steering of a vehicle according to fig. 3.

The vehicle V, according to the embodiment illustrated in fig. 2, comprises afront axle X1 with steerable wheels WL, WR, a left steerable wheel WL and aright steerable wheel WR.

The vehicle V has a main steering control arrangement A1 for automaticallycontrolling steering of the vehicle V. The main steering control arrangementA1 may be any suitable steering control arrangement for facilitating automaticsteering of the vehicle V. The main steering control arrangement A1 may bean electro-hydraulic hybrid steering control arrangement. The main steering control arrangement A1 may, for a vehicle having a driver, comprise a steeringwheel. The main steering control arrangement A1 comprises or is operablyconnected to the steerable wheels WL, WR of the vehicle V.

The main steering control arrangement A1 is according to an embodimentdeactivatable. The main steering control arrangement A1 may thus bedeactivated. The control device 100 may according to an embodiment beconfigured to deactivate the main steering control arrangement A1 _ The controldevice 100 may according to an embodiment be configured to activate the main steering control arrangement A1.

The vehicle V further has at least one auxiliary steering control arrangementA2 as backup for the main steering control arrangement A1. The auxiliarysteering control arrangement A2 may be any suitable steering controlarrangement for facilitating automatic backup steering of the vehicle V. Theauxiliary steering control arrangement A2 may be a steer-by-brake steeringcontrol arrangement. The auxiliary steering control arrangement A2 may be arear axle steering control arrangement. The auxiliary steering controlarrangement A2 may be a steering control arrangement having essentially acorresponding function as the main steering control arrangement A1. Theauxiliary steering control arrangement A2 may be operably connected/connectable to the steerable wheels WL, WR of the vehicle V.

The auxiliary steering control arrangement A2 is according to an embodimentactivatable. The auxiliary steering control arrangement A2 may thus beactivated. The control device 100 may according to an embodiment beconfigured to activate the auxiliary steering control arrangement A2. Thecontrol device 100 may according to an embodiment be configured todeactivate the auxiliary steering control arrangement A2.

The control device 100 is configured to determine the probability of the main steering control arrangement A1 malfunctioning. The control device 100 is thus configured to determine the Iikelihood of the main steering control arrangement A1 malfunctioning.

The control device 100 may be configured to continuously determine theprobability of the main steering control arrangement A1 malfunctioning. Thecontrol device 100 may be configured to intermittently determine the probabilityof the main steering control arrangement A1 malfunctioning.

The control device 100 is configured to activate the auxiliary steering controlarrangement A2 based on the thus determined probability of the main steering control arrangement A1 malfunctioning.

According to an embodiment the control device 100 is configured to activatethe auxiliary steering control arrangement A2 if the thus determined probability exceeds a predetermined threshold value.

According to an embodiment the control device 100 is configured to determinethe probability of the main steering control arrangement A1 malfunctioningbased on one or more of: the trajectory of the vehicle relative to the trajectoryT of the route R along which the vehicle is travelling; historical data regardingmalfunctioning; current weather conditions; current road conditions; anddetermined abnormal behaviour associated with the main steering control arrangement.

The trajectory of the vehicle relative to the trajectory T of the route R alongwhich the vehicle is travelling may be determined by means of a vehicletrajectory determination arrangement 112 for determining the trajectory of thevehicle relative to the trajectory T of the route R along which the vehicle istravelling. The vehicle trajectory determination arrangement may comprise oneor more detectors for detecting the trajectory of the road R along which thevehicle is travelling and the trajectory, i.e. direction, of the vehicle V relative tothe trajectory or the road R. The vehicle trajectory determination arrangementmay comprise one or more detectors for detecting the angle of the steerablewheels WL, WR. The angle of the steerable wheels WL, WR may be detected 11 indirectly via one or more detectors arranged in connection to the steering wheel mechanism of the main steering control arrangement A1.

The trajectory of the vehicle V may be determined to be a left turning directionDL of the vehicle, i.e. the vehicle is turning left. A left turning direction DL ofthe vehicle V would in fig. 2 mean that the vehicle V is turning oppositely to thetrajectory T of the road R, which is turning right.

The trajectory of the vehicle V may be determined to be a straight direction DSof the vehicle, i.e. the vehicle is driving in a straight direction. A straightdirection DS of the vehicle V would in fig. 2 mean that the vehicle V is havinganother trajectory than the trajectory T of the road R, which is turning right.

The trajectory of the vehicle V may be determined to be a road trajectorydirection DT of the vehicle, i.e. the vehicle is driving in a directioncorresponding to the trajectory T of the road. A road trajectory direction DT ofthe vehicle V would mean that the vehicle V has essentially the same trajectoryas the trajectory T of the road R, which in fig. 2 is turning right.

The trajectory of the vehicle V may be determined to be a right turning directionDR of the vehicle, i.e. the vehicle is turning right. A right turning direction DRof the vehicle V may in fig. 2 mean that the vehicle V is turning right but e.g. toa greater extent than the trajectory T of the road R, which is also turning right.

The trajectory of the vehicle V may be determined to be a varying direction ofthe vehicle, i.e. the direction may vary from right turning, left turning, trajectoryfollowing, and/or straight, i.e. the vehicle may be steered in a direction varyingback and forth in e.g. an unpredictable way.

Determining the trajectory may comprise determining whether the vehicle V issteered so that it is kept within the lane L of the road. Determining whether thevehicle is steered so that it remains within the lane L may comprise detectingthe lane L, i.e. left side LL and right side LR of the lane by means of anysuitable detector. 12 Determining the trajectory may comprise determining whether the vehicle V issteered so that it is kept within a desired driving corridor G1, G2 of the lane Lof the road R. The driving corridor according to the present invention may haveany suitable shape. The driving corridor has according to an embodiment afunnel shape extending ahead of the vehicle in connection to the lane in whichthe vehicle is driving. The driving corridor G1, G2 has according to theembodiment illustrated in fig. 2 essentially straight and parallel lines G1, G2extending ahead of the vehicle V in connection to the lane L in which thevehicle is driving. The driving corridor may be determined based on one ormore of width of the lane L in which the vehicle is driving; curvature of the roadR on which the vehicle is driving and configuration of the vehicle V.

Historical data regarding malfunctioning of the main steering controlarrangement A1 may be stored in a storage device for storing historical dataregarding malfunctioning of the main steering control arrangement A1. Such astorage device may be an on-board storage device arranged on board thevehicle V and/or an external storage device arranged externally to the vehicleand being operably connectable to the control device 100. The historical dataregarding malfunctioning of the main steering control arrangement A1 maycomprise any data which may indicate malfunctioning or risk of malfunctioningof the main steering control arrangement A1. Such data may comprise dataregarding trajectory of the vehicle relative to the trajectory of the route alongwhich the vehicle is travelling, steering angle, steering angle velocity, steeringtorque resistance, strange sounds from mechanism of the main steeringcontrol arrangements or the like.

Gurrent weather conditions may be determined by means of one or moreweather detectors arranged on board the vehicle. Gurrent weather conditionsmay be determined by means of weather data from one or more weatherstations, weather apps or the like operably connectable to the control device,e.g. via a vehicle-to-infrastructure arrangement. 100. Gurrent weather conditions may be determined from other vehicle by means of a vehicle-to- 13 vehicle control arrangement. Current weather conditions which may affect thesteering of the vehicle and hence the main steering control arrangement maye.g. be heavy side winds, precipitation such as snowfall.

Current road conditions may be determined by means of one or more detectorsarranged on board the vehicle and configured to detect the road conditionssuch as one or more cameras, one or more temperature sensors and the like.Current road conditions may be determined by means of road condition datafrom one or more stations, apps or the like operably connectable to the controldevice, e.g. via a vehicle-to-infrastructure arrangement. 100. Current roadconditions may be determined from other vehicle by means of a vehicle-to-vehicle control arrangement. Current road conditions which may affect thesteering of the vehicle and hence the main steering control arrangement may e.g. be slippery roads, e.g. icy roads.

Abnormal behaviour associated with the main steering control arrangementmay be determined by means of one or more detectors arranged in connectionto the main steering control arrangement A1. Such detectors may be arrangedto detect the current steering angle of the steerable wheels/steeringwheel/steering mechanism of the main steering control arrangement A1, thecurrent steering angle velocity, torque resistance of the steerablewheels/steering wheel/steering mechanism of the main steering controlarrangement A1. Abnormal behaviour associated with the main steeringcontrol arrangement may be associated with the trajectory of the vehicle relative to the trajectory T of the route R along which the vehicle is travelling.

According to an embodiment the control device 100, when determining theprobability of the main steering control arrangement A1 malfunctioning, isconfigured to determine kind of malfunction. Kind of malfunction of the mainsteering control arrangement A1 may e.g. be associated with the trajectory ofthe vehicle relative to the trajectory T of the route R along which the vehicle istravelling. For a right turning road R as in fig. 2, a left turning direction DL ofthe vehicle V, and probably also a straight direction DS of the vehicle and/or 14 varying direction of the vehicle may indicate a serious kind of malfunctioningwhich may require immediate action and deactivation of the main steeringcontrol arrangement A1 and activation of the auxiliary steering controlarrangement A2. For a right turning road R as in fig. 2, a right turning directionDR of the vehicle V may, depending on the degree of right turning relative tothe right turning of the road R, indicate a less serious kind of malfunctioningwhich may not require deactivation of the main steering control arrangementA1 but maybe assistance of the auxiliary steering control arrangement A2. Fora right turning road R as in fig. 2, a road trajectory direction DT of the vehiclemay, depending on indicate no malfunction or a less serious kind ofmalfunctioning which may not require deactivation of the main steering controlarrangement A1 but maybe assistance of an auxiliary steering control arrangement A2.

The vehicle V is, according to an embodiment, arranged to be operated inaccordance with a method l\/l1 for controlling steering of a vehicle according tofig. 4.

Fig. 3 schematically illustrates a block diagram of a control device 100 forcontrolling steering of a vehicle according to an embodiment of the presentdisclosure.

The vehicle has a main steering control arrangement for automaticallycontrolling steering of the vehicle and at least one auxiliary steering control arrangement as backup for the main steering control arrangement.

The control device 100 is configured to control steering of a vehicle duringoperation of the vehicle.

The control device 100 for controlling steering of a vehicle during operation ofthe vehicle may be comprised in a system l for controlling steering of a vehicleduring operation of the vehicle.

The control device 100 may be implemented as a separate entity or distributedin two or more physical entities. The control device 100 may comprise one ormore computers. The control device 100 may thus be implemented or realisedby the control device comprising a processor and a memory, the memorycomprising instructions, which when executed by the processor causes thecontrol device to perform the herein disclosed method.

The control device 100 may comprise one or more electronic control units,processing units, computers, server units or the for controlling steering of avehicle during operation of the vehicle. The control device 100 may comprisecontrol device such as one or more electronic control units arranged on boarda vehicle. The control device 100 may comprise one or more electronic controlunits of the vehicle. The control device 100 may comprise one or moreelectronic control units, processing units, computers, server units or the like ofan off-board system arranged externally to the vehicle and being operablyconnectable to the vehicle.

The control device 100 is configured to determine the probability of the mainsteering control arrangement malfunctioning. The control device 100 may beconfigured to continuously determine the probability of the main steeringcontrol arrangement malfunctioning. The control device 100 may be configuredto intermittently determine the probability of the main steering control arrangement malfunctioning.

The system I may comprise a malfunction probability determination device 110arranged to determine the probability of the main steering control arrangement malfunctioning.

The control device 100 may comprise or be operably connectable to themalfunction probability determination device 110.

According to an embodiment the control device 100 is configured to determinethe probability of the main steering control arrangement malfunctioning based on one or more of: the trajectory of the vehicle relative to the trajectory of the 16 route along which the vehicle is travelling; historical data regardingmalfunctioning; current weather conditions; current road conditions; anddetermined abnormal behaviour associated with the main steering control arrangement.

According to an embodiment the malfunction probability determination device110 comprises a vehicle trajectory determination arrangement 112 fordetermining the trajectory of the vehicle relative to the trajectory of the routealong which the vehicle is travelling. The vehicle trajectory determinationarrangement 112 may comprise one or more detectors for detecting thetrajectory of the road along which the vehicle is travelling and the trajectory,i.e. direction, of the vehicle relative to the trajectory or the road. The vehicletrajectory determination arrangement 112 may comprise one or moredetectors for detecting the steering angle, comprising detecting steering wheelangle where applicable, and/or steering angle of any portion of the mainsteering control arrangement or portion connected thereto comprising theangle of steerable wheels steerable by means of the main steering controlarrangement or portions affecting the angle of the steerable wheels of the vehicle.

The control device 100 may comprise or be operably connectable to thevehicle trajectory determination arrangement 112.

According to an embodiment the malfunction probability determination device110 comprises a historical data consideration arrangement 1 14 for consideringhistorical data regarding malfunction of main steering control arrangement.The historical data consideration arrangement 114 may be configured tocompare historical data regarding malfunction of main steering controlarrangement with current data regarding the main steering controlarrangement so as to determine probability of malfunction of the main steering control arrangement. 17 The control device 100 may comprise or be operably connectable to thehistorical data consideration arrangement 114.

According to an embodiment the malfunction probability determination device110 comprises a weather condition determination arrangement 116 for determining the current weather conditions.

The weather condition determination arrangement 116 may comprise one ormore weather detectors. The weather detectors may comprise one or morewind detectors. The weather detectors may comprise one or more raindetectors. The weather detectors may comprise one or more temperaturedetectors. The weather condition determination arrangement 116 comprisesaccording to an embodiment a weather data extraction device for extractingexternal weather data from one or more external weather data units comprisingany suitable external server unit. Thus determined weather conditions maycomprise wind conditions comprising wind directions, rain and extent of rain, SHOW and eXtent Of SHOW, CUlTent tempefatUfe etC.

The control device 100 may comprise or be operably connectable to the weather condition determination arrangement 116 According to an embodiment the malfunction probability determination device110 comprises a road condition determination arrangement 118 for determining the current road conditions.

The road condition determination arrangement118 may comprise one or moreroad detectors for detecting the surface of the road along which the vehicle istravelling. The road detectors may comprise one or more cameras and/or oneor more laser scanners and/or one or more radars. The road detectors maycomprise sensors/detectors arranged within the tyres of the vehicle wheels,indirect sensors/detectors such as wheel speed sensors, optical sensors orthe like. The road condition determination arrangement 118 comprisesaccording to an embodiment a road data extraction device for extracting external data about road conditions from one or more external data units 18 comprising any suitable external server unit. Thus determined road conditionsmay comprise slippery road due to e.g. ice on the road, snow on the road, oilon the road, gravel on the road, water on the road, curves of the road or otherroad conditions that may affect controlling steering of the vehicle along the road.

The control device 100 may comprise or be operably connectable to the road condition determination arrangement 118.

According to an embodiment the malfunction probability determination device110 comprises a main steering control behaviour determination arrangement119 for determining possible abnormal behaviour associated with the main steering control arrangement.

The main steering control behaviour determination arrangement 119 maycomprise one or more detectors arranged in connection to the main steeringcontrol arrangement for determining abnormal behaviour. Such detectors maybe arranged to detect the current steering angle of the steerablewheels/steering wheel/steering mechanism of the main steering controlarrangement, the current steering angle velocity, torque resistance of thesteerable wheels/steering wheel/steering mechanism of the main steeringcontrol arrangement. Abnormal behaviour associated with the main steeringcontrol arrangement may be associated with the trajectory of the vehiclerelative to the trajectory of the route along which the vehicle is travelling. Themain steering control behaviour determination arrangement119 may comprisethe vehicle trajectory determination arrangement 112. The main steeringcontrol behaviour determination arrangement 119 may comprise the historical data consideration arrangement 114.

The control device 100 may comprise or be operably connectable to the main steering control behaviour determination arrangement 119. 19 According to an embodiment the control device 100, when determining theprobability of the main steering control arrangement malfunctioning, isconfigured to determine kind of malfunction.

According to an embodiment the malfunction probability determination device110 comprises a malfunction kind determination arrangement 110a fordetermining kind of malfunction of the main steering control arrangement. Kindof malfunction of the main steering control arrangement may e.g. beassociated with the trajectory of the vehicle relative to the trajectory T of theroute along which the vehicle is travelling. The malfunction kind determinationarrangement 110a may comprise the vehicle trajectory determinationarrangement 112.

The control device 100 may comprise or be operably connectable to the malfunction kind determination arrangement 110a.

The malfunction probability determination device 110 is according to anembodiment configured to process data from one or more of the vehicletrajectory determination arrangement 112, the historical data considerationarrangement 114, the weather condition determination arrangement 116, theroad condition determination arrangement 118, and the main steering controlbehaviour determination arrangement 119 for determining the probability of the main steering control arrangement malfunctioning.

The malfunction kind determination arrangement 110a is according to anembodiment configured to process data from one or more of the vehicletrajectory determination arrangement 112, the historical data considerationarrangement 114, the weather condition determination arrangement 116, theroad condition determination arrangement 118, and the main steering controlbehaviour determination arrangement 119 for determining the kind ofmalfunction of the main steering control arrangement and the probability of that kind of malfunction occurring.

The system I may comprise a storage device 120 for storing historical dataregarding malfunctioning of the main steering control arrangement. Thestorage device 120 may be an on-board storage device arranged on board thevehicle. The storage device 120 may be an external storage device arrangedexternally to the vehicle. The storage device 120 may be comprised in thehistorical data consideration arrangement 114.

The control device 100 may comprise or be operably connectable to thestorage device 120.

The control device 100 is configured to activate an auxiliary steering controlarrangement based on the thus determined probability of the main steering control arrangement malfunctioning.

The system l may comprise an auxiliary steering control arrangementactivation device 130 for activating an auxiliary steering control arrangementbased on the thus determined probability of the main steering control arrangement malfunctioning.

The auxiliary steering control arrangement activation device 130 mayaccording to an embodiment also be arranged to deactivate an activatedauxiliary steering control arrangement if it has been determined that the main steering control arrangement is not malfunctioning.

The control device 100 may comprise or be operably connectable to the auxiliary steering control arrangement activation device 130.

According to an embodiment the control device 100 is configured to activatean auxiliary steering control arrangement if the thus determined probabilityexceeds a predetermined threshold value.

According to an embodiment of the control device 100 the predeterminedthreshold value depends on the kind of malfunction. 21 The control device 100 is configured to deactivate the main steering controlarrangement based on the thus determined probability of the main steeringcontrol arrangement malfunctioning and kind of malfunction of the main steering control arrangement.

The system I may comprise a main steering control arrangement deactivationdevice 140 for deactivating the main steering control arrangement based onthe thus determined probability of the main steering control arrangementmalfunctioning and kind of malfunction of the main steering control arrangement.

According to an embodiment the control device 100, when an auxiliary steeringcontrol arrangement has been activated, is configured to determine whetherthe main steering control arrangement and/or auxiliary steering controlarrangement are to be remained activated or be deactivated based on one ormore of: whether the main steering control arrangement is determined toactually malfunction; and kind of malfunction of the main steering control arrangement.

The malfunction probability determination device 110 comprises according toan embodiment a malfunction determination device for determining whether the main steering control arrangement is malfunctioning.

Kind of malfunction of the main steering control arrangement may e.g. beassociated with the trajectory of the vehicle relative to the trajectory of the routealong which the vehicle is travelling. The vehicle trajectory determinationarrangement 112 may thus be utilized to determine kind of malfunction of the main steering control arrangement. lf it is determined that the trajectory of the vehicle corresponds to a turningdirection opposite to the turning trajectory of the road along which the vehicleis travelling or a straight trajectory or an alternating trajectory, it may indicatea serious kind of malfunctioning which may require immediate action and 22 deactivation of the main steering control arrangement and activation of the auxiliary steering control arrangement. lf it is determined that the trajectory of the vehicle corresponds to a turningdirection in the same direction but to a different degree compared to the turningtrajectory of the road along which the vehicle is travelling, it may, dependingon the difference in degree of turning, indicate a less serious kind ofmalfunctioning which may not require deactivation of the main steering controlarrangement but maybe assistance of the auxiliary steering controlarrangement in order for the main steering control arrangement to correctly steer the vehicle. lf it is determined that the trajectory of the vehicle corresponds to a turningdirection corresponding to the turning trajectory of the road along which thevehicle is travelling may indicate no malfunction or a less serious kind ofmalfunctioning which may not require deactivation of the main steering controlarrangement but maybe assistance of an auxiliary steering controlarrangement or actually deactivation of the auxiliary steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 10, operably connected to the malfunction probability determination device110. According to an embodiment of the invention, the control device 100 isvia the link 10 arranged to receive a signal from the malfunction probabilitydetermination device 110 representing data about probability of the main steering control arrangement malfunctioning.

According to an embodiment of the invention, the control device 100 is, via alink 10a, operably connected to the malfunction kind determinationarrangement 110a. According to an embodiment of the invention, the controldevice 100 is via the link 10a arranged to receive a signal from the malfunctionkind determination arrangement 110a representing data about kind of 23 malfunction of the main steering control arrangement comprising probability ofthe malfunction.

According to an embodiment of the invention, the control device 100 is, via alink 12,arrangement 112. According to an embodiment of the invention, the control operably connected to the vehicle trajectory determinationdevice 100 is via the link 12 arranged to receive a signal from the vehicletrajectory determination arrangement 112 representing data about trajectoryof the vehicle relative to the trajectory of the route along which the vehicle is travelling.

According to an embodiment of the invention, the control device 100 is, via alink 20a, operably connected to the storage device 120. According to anembodiment of the invention, the control device 100 is via the link 20a arrangedto receive a signal from the storage device 120 representing historical data regarding malfunctioning of the main steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 14a, operably connected to the historical data consideration arrangement114. According to an embodiment of the invention, the control device 100 isvia the link 14a arranged to send a signal to the historical data considerationarrangement 114 representing historical data about earlier malfunction of main steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 14b, operably connected to the historical data consideration arrangement114. According to an embodiment of the invention, the control device 100 isvia the link 14b arranged to receive a signal from the historical dataconsideration arrangement 114 representing data about comparison of currentdata of main steering control arrangement with historical data regarding malfunction of main steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via a link 16, operably connected to the weather condition determination 24 arrangement 116. According to an embodiment of the invention, the controldevice 100 is via the link 16 arranged to receive a signal from the weathercondition determination arrangement 116 representing data about current weather conditions.

According to an embodiment of the invention, the control device 100 is, via alink 18, operably connected to the road condition determination arrangement118. According to an embodiment of the invention, the control device 100 isvia the link 18 arranged to receive a signal from the road conditiondetermination arrangement 118 representing data about current road conditions.

According to an embodiment of the invention, the control device 100 is, via alink 19a, operably connected to the main steering control behaviourdetermination arrangement 119. According to an embodiment of the invention,the control device 100 is via the link 19a arranged to send a signal to the mainsteering control behaviour determination arrangement 119 representing dataabout trajectory of the vehicle relative to the trajectory of the route along whichthe vehicle is travelling.

According to an embodiment of the invention, the control device 100 is, via alink 19b, operably connected to the main steering control behaviourdetermination arrangement 119. According to an embodiment of the invention,the control device 100 is via the link 19b arranged to send a signal to the mainsteering control behaviour determination arrangement 119 representing dataabout comparison of current data of main steering control arrangement with historical data regarding malfunction of main steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 19c, operably connected to the main steering control behaviourdetermination arrangement 119. According to an embodiment of the invention, the control device 100 is via the link 19c arranged to receive a signal from the main steering control behaviour determination arrangement 119 representingdata about abnormal behaviour associated with the main steering control arrangement.

The control device 10 is according to an embodiment configured to processdata from one or more of the vehicle trajectory determination arrangement 112,the historical data consideration arrangement 114, the weather condition116, thearrangement 118, and the main steering control behaviour determination determination arrangement road condition determinationarrangement 119 for determining the probability of the main steering control arrangement malfunctioning.

According to an embodiment of the invention, the control device 100 is, via alink 20b, operably connected to the storage device 120. According to anembodiment of the invention, the control device 100 is via the link 20b arrangedto send signals to the storage device 120 representing data regardingmalfunctioning of the main steering control arrangement for storage.

According to an embodiment of the invention, the control device 100 is, via alink 30a, operably connected to the auxiliary steering control arrangementactivation device 130. According to an embodiment of the invention, the controldevice 100 is via the link 30a arranged to send a signal to the auxiliary steeringcontrol arrangement activation device 130 representing data about thusdetermined probability of the main control steering arrangement malfunctioning.

According to an embodiment of the invention, the control device 100 is, via alink 30b, operably connected to the auxiliary steering control arrangementactivation device 130. According to an embodiment of the invention, the controldevice 100 is via the link 30b arranged to send a signal to the auxiliary steeringcontrol arrangement activation device 130 representing data about kind of malfunction of the main steering control arrangement. 26 According to an embodiment of the invention, the control device 100 is, via alink 30c, operably connected to the auxiliary steering control arrangementactivation device 130. According to an embodiment of the invention, the controldevice 100 is via the link 30c arranged to receive a signal from the auxiliarysteering control arrangement activation device 130 representing data aboutactivation status of the auxiliary steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 40a, operably connected to the main steering control arrangementdeactivation device 140. According to an embodiment of the invention, thecontrol device 100 is via the link 40a arranged to send a signal to the mainsteering control arrangement deactivation device 140 representing data aboutthus determined probability of the main steering control arrangement malfunctioning and where applicable possible data about actual malfunction.

According to an embodiment of the invention, the control device 100 is, via alink 40b, operably connected to the main steering control arrangementdeactivation device 140. According to an embodiment of the invention, thecontrol device 100 is via the link 40b arranged to send a signal to the mainsteering control arrangement deactivation device 140 representing data about kind of malfunction of the main steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 40c, operably connected to the main steering control arrangementdeactivation device 140. According to an embodiment of the invention, thecontrol device 100 is via the link 40c arranged to send a signal to the mainsteering control arrangement deactivation device 140 representing data about activation status of the auxiliary steering control arrangement.

According to an embodiment of the invention, the control device 100 is, via alink 40d, operably connected to the main steering control arrangementdeactivation device 140. According to an embodiment of the invention, the control device 100 is via the link 40d arranged to receive a signal from the main 27 steering control arrangement deactivation device 140 representing data aboutactivation status of the main steering control arrangement. lf the vehicle is equipped with more than one auxiliary steering control arrangement, probability of the activated auxiliary steering controlarrangement malfunctioning may be determined in accordance with theprobability determination regarding malfunctioning of the main steering controlarrangement. A determined probability of that auxiliary steering controlarrangement also malfunctioning may be a basis for activation of a second auxiliary steering control arrangement. lf the vehicle is equipped with more than one auxiliary steering controlarrangement, and the auxiliary steering control arrangements are of differenttypes, selection of which of those auxiliary steering control arrangements thatshould be activated may be based on determined kind of malfunction of the main steering control arrangement.

The control device 100 for controlling steering of a vehicle is, according to anembodiment, adapted to perform the method l\/l1 described below withreference to fig. 4.

Fig. 4 schematically illustrates a block diagram of a method l\/l1 performed bya control device for controlling steering of a vehicle according to anembodiment of the present disclosure.

Said vehicle has a main steering control arrangement for automaticallycontrolling steering of the vehicle and at least one auxiliary steering control arrangement as backup for the main steering control arrangement.

According to the embodiment the method comprises a step S1. ln this step theprobability of the main steering control arrangement malfunctioning isdetermined. The probability of the main steering control arrangementmalfunctioning is according to an embodiment arranged to be determined by 28 means of a malfunction probability determination device, e.g. a malfunctionprobability determination device 110 described with reference to fig. 3.

According to the embodiment the method comprises a step S2. ln this step anauxiliary steering control arrangement is activated based on the thusdetermined probability of the main steering control arrangementmalfunctioning. The activation of an auxiliary steering control arrangement isaccording to an embodiment arranged to be performed by means of anauxiliary steering control arrangement activation device, e.g. an auxiliarysteering control arrangement activation device 130 described with reference to fig. 3.

According to an embodiment of the method the step of activating an auxiliarysteering control arrangement based on the thus determined probability of themain steering control arrangement malfunctioning comprises activating anauxiliary steering control arrangement if the thus determined probabilityexceeds a predetermined threshold value.

According to an embodiment of the method the step of determining theprobability of the main steering control arrangement malfunctioning isperformed based on one or more of: the trajectory of the vehicle relative to thetrajectory of the route along which the vehicle is travelling; historical dataregarding malfunctioning; current weather conditions; current road conditions;and determined abnormal behaviour associated with the main steering control arrangement.

The trajectory of the vehicle relative to the trajectory of the route along whichthe vehicle is travelling may be arranged to be determined by means of avehicle trajectory determination arrangement, e.g. a vehicle trajectorydetermination arrangement 112 described with reference to fig. 3.

Consideration of historical data regarding malfunction of main steering controlarrangement may be arranged to be determined by means of a historical data 29 consideration arrangement, e.g. a historical data consideration arrangement114 described with reference to fig. 3.

Current weather conditions may be arranged to be determined by means of aweather condition determination arrangement, e.g. a weather condition determination arrangement 116 described with reference to fig. 3.

Current road conditions may be arranged to be determined by means of a roadcondition determination arrangement, e.g. a road condition determination arrangement 118 described with reference to fig. 3.

Abnormal behaviour associated with the main steering control arrangementmay be arranged to be determined by means of a main steering controlbehaviour determination arrangement, e.g. a main steering control behaviour determination arrangement 119 described with reference to fig. 3.

According to an embodiment of the method the step of determining theprobability of the main steering control arrangement malfunctioning comprisesthe step of determining kind of malfunction. Kind of malfunction of the mainsteering control arrangement may be arranged to be determined by means ofa malfunction kind determination arrangement, e.g. a malfunction kind determination arrangement 110a described with reference to fig. 3.

According to an embodiment of the method the predetermined threshold valuedepends on the kind of malfunction.

According to an embodiment the method, when an auxiliary steering controlarrangement has been activated, comprises the step of determining whetherthe main steering control arrangement and/or auxiliary steering controlarrangement are to be remained activated or be deactivated based on one ormore of: whether the main steering control arrangement is determined toactually malfunction; and kind of malfunction of the main steering control arrangement.

The method l\/l1 performed by a control device for controlling steering of avehicle is according to an embodiment adapted to be performed by the controldevice 100 described above with reference to fig. 3.

The method l\/l1 performed by a control device for controlling steering of avehicle is according to an embodiment adapted to be performed by the systeml described above with reference to fig. 3.

With reference to fig. 5, a diagram of a computer 500/apparatus 500 is shown.The control device 100 described with reference to fig. 3 may according to anembodiment comprise apparatus 500. Apparatus 500 comprises a non-volatilememory 520, a data processing device 510 and a read/write memory 550.Non-volatile memory 520 has a first memory portion 530 wherein a computerprogram, such as an operating system, is stored for controlling the function ofapparatus 500. Further, apparatus 500 comprises a bus controller, a serialcommunication port, I/O-means, an A/D-converter, a time date entry andtransmission unit, an event counter and an interrupt controller (not shown).

Non-volatile memory 520 also has a second memory portion 540.

A computer program P is provided comprising routines for controlling steeringof a vehicle.

The program P comprises routines for determining the probability of the mainsteering control arrangement malfunctioning. The program P comprisesroutines for activating an auxiliary steering control arrangement based on thethus determined probability of the main steering control arrangement malfunctioning.

The routines for activating an auxiliary steering control arrangement based onthe thus determined probability of the main steering control arrangement 31 malfunctioning comprises routines for activating an auxiliary steering controlarrangement if the thus determined probability exceeds a predeterminedthreshold value.

The routines for determining the probability of the main steering controlarrangement malfunctioning comprises routines for performing determinationof the probability of the main steering control arrangement malfunctioningbased on one or more of: the trajectory of the vehicle relative to the trajectoryof the route along which the vehicle is travelling; historical data regardingmalfunctioning; current weather conditions; current road conditions; anddetermined abnormal behaviour associated with the main steering control arrangement.

The routines for determining the probability of the main steering controlarrangement malfunctioning comprises routines for determining kind ofmalfunction. The predetermined threshold value depends on the kind ofmalfunction. routines for The program P comprises adapting the predetermined threshold value depending on the kind of malfunction.

The program P comprises routines for determining, when an auxiliary steeringcontrol arrangement has been activated, whether the main steering controlarrangement and/or auxiliary steering control arrangement are to be remainedactivated or be deactivated based on one or more of: whether the mainsteering control arrangement is determined to actually malfunction; and kind of malfunction of the main steering control arrangement.

The computer program P may be stored in an executable manner or in acompressed condition in a separate memory 560 and/or in read/write memory550.

When it is stated that data processing device 510 performs a certain functionit should be understood that data processing device 510 performs a certainpart of the program which is stored in separate memory 560, or a certain part of the program which is stored in read/write memory 550. 32 Data processing device 510 may communicate with a data communicationsport 599 by means of a data bus 515. Non-volatile memory 520 is adapted forcommunication with data processing device 510 via a data bus 512. Separatememory 560 is adapted for communication with data processing device 510via a data bus 511. Read/write memory 550 is adapted for communication withdata processing device 510 via a data bus 514. To the data communicationsport 599 e.g. the links connected to the control unit 100 may be connected.

When data is received on data port 599 it is temporarily stored in secondmemory portion 540. When the received input data has been temporarilystored, data processing device 510 is set up to perform execution of code in amanner described above. The signals received on data port 599 may be usedby apparatus 500 for determining the probability of the main steering controlarrangement malfunctioning. The signals received on data port 599 may beused by apparatus 500 for activating an auxiliary steering control arrangementbased on the thus determined probability of the main steering control arrangement malfunctioning.

The signals used by apparatus 500 for activating an auxiliary steering controlarrangement based on the thus determined probability of the main steeringcontrol arrangement malfunctioning comprises signals used for activating anauxiliary steering control arrangement if the thus determined probability exceeds a predetermined threshold value.

The signals used by apparatus 500 for determining the probability of the mainsteering control arrangement malfunctioning comprises signals used forperforming determination of the probability of the main steering controlarrangement malfunctioning based on one or more of: the trajectory of thevehicle relative to the trajectory of the route along which the vehicle istravelling; historical data regarding malfunctioning; current weather conditions;current road conditions; and determined abnormal behaviour associated with the main steering control arrangement. 33 The signals used by apparatus 500 for determining the probability of the main steering control arrangement malfunctioning comprises routines fordetermining kind of malfunction. The predetermined threshold value dependson the kind of malfunction. The signals received on data port 599 may be usedby apparatus 500 for adapting the predetermined threshold value depending on the kind of malfunction.

The signals received on data port 599 may be used by apparatus 500 fordetermining, when an auxiliary steering control arrangement has beenactivated, whether the main steering control arrangement and/or auxiliarysteering control arrangement are to be remained activated or be deactivatedbased on one or more of: whether the main steering control arrangement isdetermined to actually malfunction; and kind of malfunction of the main steering control arrangement.

The signals received on data port 599 may be used by apparatus 500 forutilizing the virtual inertial measurement units for redundancy in co-validation so as to facilitate improved Automotive Safety lntegrity Level.

Parts of the methods described herein may be performed by apparatus 500 bymeans of data processing device 510 running the program stored in separatememory 560 or read/write memory 550. When apparatus 500 runs theprogram, parts of the methods described herein are executed.

The foregoing description of the preferred embodiments of the presentinvention has been provided for the purposes of illustration and description. ltis not intended to be exhaustive or to limit the invention to the precise formsdisclosed. Obviously, many modifications and variations will be apparent topractitioners skilled in the art. The embodiments were chosen and describedin order to best explain the principles of the invention and its practicalapplications, thereby enabling others skilled in the art to understand theinvention for various embodiments and with the various modifications as are suited to the particular use contemplated.

Claims

34 CLAIIVIS

1. A method (l\/l1) performed by a control device (100) for controlling steeringof a vehicle (V), said vehicle (V) having a main steering control arrangement(A1) for automatically controlling steering of the vehicle and at least oneauxiliary steering control arrangement (A2) as backup for the main steeringcontrol arrangement (A1), the method comprising the steps of: - determining (S1) the probability of the main steering control arrangement(A1) malfunctioning; and - activating an auxiliary steering control arrangement (A2) based on the thusdetermined probability of the main steering control arrangement (A1) malfunctioning.

2. A method according to claim 1, wherein the step of activating an auxiliarysteering control arrangement (A2) based on the thus determined probability ofthe main steering control arrangement (A1) malfunctioning comprisesactivating an auxiliary steering control arrangement (A2) if the thus determinedprobability exceeds a predetermined threshold value.

3. A method according to claim 1 or 2, wherein the step of determining theprobability of the main steering control arrangement (A1) malfunctioning isperformed based on one or more of: the trajectory (DL, DS, DT, DR) of thevehicle (V) relative to the trajectory (T) of the route (R) along which the vehicleis travelling; historical data regarding malfunctioning; current weatherconditions; current road conditions; and determined abnormal behaviourassociated with the main steering control arrangement (A1).

4. A method according to any of claims 1-3, wherein the step of determiningthe probability of the main steering control arrangement (A1) malfunctioning comprises the step of determining kind of malfunction.

5. A method according to claim 4, wherein the predetermined threshold value depends on the kind of malfunction.

6. A method according to claim 4 or 5, when an auxiliary steering controlarrangement (A2) has been activated, comprising the step of determiningwhether the main steering control arrangement (A1) and/or auxiliary steeringcontrol arrangement (A2) should remaineal activated or bedeactivated based on one or more of: whether the main steering controlarrangement (A1) is determined to actually malfunction; and kind ofmalfunction of the main steering control arrangement (A1).

7. A control device (1 OO) for controlling steering of a vehicle (V), said vehicle(V) having a main steering control arrangement (A1) for automaticallycontrolling steering of the vehicle and at least one auxiliary steering controlarrangement (A2) as backup for the main steering control arrangement (A1),the control device (1 OO) being configured to: - determine the probability of the main steering control arrangement (A1)malfunctioning; and - activate an auxiliary steering control arrangement (A2) based on the thusdetermined probability of the main steering control arrangement (A1) malfunctioning.

8. A control device according to claim 7, wherein the control device (100) isconfigured to activate an auxiliary steering control arrangement (A2) if the thusdetermined probability exceeds a predetermined threshold value.

9. A control device according to claim 7 or 8, wherein the control device (1 OO)is configured to determine the probability of the main steering controlarrangement (A1) malfunctioning based on one or more of: the trajectory ofthe vehicle relative to the trajectory (DL, DS, DT, DR) of the route (R) alongwhich the vehicle is travelling; historical data regarding malfunctioning; currentweather conditions; current road conditions; and determined abnormal behaviour associated with the main steering control arrangement (A1).

10. A control device according to any of claims 7-9, wherein the control device (100) when determining the probability of the main steering control 36 arrangement (A1) malfunctioning is configured to determine kind of malfunction.

11.A control device according to claim 10, wherein the predetermined threshold value depends on the kind of malfunction.

12. A control device according to claim 10 or 11, wherein the control device(100), when an auxiliary steering control arrangement (A2) has been activated,is configured to determine whether the main steering control arrangement (A1)and/or auxiliary steering control arrangement (A2) gﬁgagidmaræebe remaineeiactivated or be deactivated based on one or more of: whether the mainsteering control arrangement (A1) is determined to actually malfunction; andkind of malfunction of the main steering control arrangement (A1).

13. A vehicle (V1) comprising a control device (100) according to any of claims7-12.

14. A computer program (P) for controlling steering of a vehicle, said computerprogram (P) comprising program code which, when run on an electroniccontrol unit (100) or another computer (500) connected to the electronic controlunit (100), causes the electronic control unit to perform the ntethod accordingto anyf of claims 1~6 the--staps--aeee:fdirwg--te-elairn--i-ä_

15.A computer readable medium comprising instructions which, whenexecuted by a computer, cause the computer to carry out the method according to anyone of claims 1-6.