SE542273C2

SE542273C2 - Method and control arrangement for lateral vehicle displacement

Info

Publication number: SE542273C2
Application number: SE1751283A
Authority: SE
Inventors: Jenny Eriksson; Johannes Slettengren; Jonny Andersson; Joseph Ah-King
Original assignee: Scania Cv Ab
Priority date: 2017-10-16
Filing date: 2017-10-16
Publication date: 2020-03-31
Also published as: DE102018007580A1; BR102018069679A2; SE1751283A1

Abstract

SUMMARYMethod (400) and control arrangement (310) in a vehicle (100) for lateral displacement (240) of a vehicle combination (100) comprising a vehicle (101) and a trailer (102), during passage of a curve (200). The method (400) comprises: detecting (401) the curve (200) ahead of the vehicle combination (100); determining (402) a critical passage of the curve (200); determining (403) width (230) of a driving lane (110) at the curve (200); predicting (404) angular movement of the trailer (102) relative the vehicle (101) during passage of the curve (200), based on a mathematical model; determining (406) the lateral displacement (240) of the vehicle (101) when entering the curve (200), based on the predicted (404) angular movement of the trailer (102), in order to keep the vehicle combination (100) within the driving lane (110); and adjusting (407) the lateral displacement (240) of the vehicle (101), according to the lateral displacement (240).

Description

METHOD AND CONTROL ARRANGEMENT FOR LATERAL VEHICLE DISPLACEMENT TECHNICAL FIELD This document relates to a method and a control arrangement in a vehicle. More particularly, a method and a control arrangement for lateral displacement during passage of a curve of a vehicle combination comprising a vehicle and a trailer articulatedly attached to the vehicle at a coupling point, are described.

BACKGROUND Vehicles with articulation points pose difficult challenges for operators. As an example, in a trailer-truck configuration with an articulation point between the tractor and the trailer, the operator must carefully monitor the angle between the tractor and the trailer to keep within a lane. Similar challenges may face operators of articulated buses, light-duty trucks with trailers (e.g., boat/ vehicle trailers, cargo trailers, etc.), or the like.

A Lane Keep Assisting function of a vehicle acquires data describing the ahead road shape and plans the movement of the vehicle accordingly, as to stay in lane. There is today no known, successful, Lane Keep Assist function adapted for articulated vehicles. It would therefore be desired to develop a Lane Keep Assist function that could be used also by an articulated vehicle. However, several problems are associated therewith.

A well-functioning Lane Keep Assist needs to keep all parts of the vehicle in the lane at all times, also when turning in a curve. In order to achieve this the planning needs to consider which type of vehicle that is in use. An articulated vehicle has one or several coupling points which the trailer(s) can rotate about. In a curve the trailer(s) will be displaced and might cut the curve tighter than the tractor. This needs to be compensated for when approaching the curve so that the trailer does not enter the adjacent lane.

Some few attempts have been made in order to achieve a Lane Keep Assist functionality for articulated vehicles: Document US2010191421 describes a method for lane keep assistance for an articulated vehicle, taking into account how a trailer is moving in relation to the tractor, thus ensuring that the entire vehicle combination remains in the lane when driving. The method takes into account gear speed of the tractor and trailer.

However, the document does not describe a lane keep assistance enabled to displace the vehicle combination laterally in order to keep within the lane.

Document DE102013000199 describes a method of lane keep assistance, taking into consideration how a trailer is moving in relation to the tractor so as to ensure that the entire vehicle combination remains in the lane when driving. The method takes into account the gear angle of the vehicle, but not of the trailer.

Document US9428188 describes a method of lane keep assistance, taking into consideration how a trailer is moving in relation to the tractor so as to ensure that the entire vehicle combination remains in the lane when driving. The method takes into account the gear angle of the vehicle, but not of the trailer.

All of the solutions described in the enumerated documents are using rather complex models based on continuous sensor measurements, which makes the proposed solutions vulnerable e.g. for defect sensors. By using complex models, high processor capacity is required, leading to increased production costs.

It would thus be desired to improve a Lane Keep Assist function of a vehicle with an articulation point.

SUMMARY It is therefore an object of this invention to solve at least some of the above problems and improving lateral displacement of a vehicle combination when passing a curve.

According to a first aspect of the invention, this objective is achieved by a method in a vehicle for lateral displacement of a vehicle combination comprising a vehicle and a trailer articulatedly attached to the vehicle at a coupling point, during passage of a curve. The method comprises detecting the curve ahead of the vehicle combination. Further, the method also comprises determining a critical part of the detected curve. The method also comprises determining width of a driving lane at the detected curve. Furthermore, the method also comprises predicting angular movement of the trailer relative the vehicle during passage of the detected curve at the determined critical curve passage, based on a mathematical model. The method in addition also comprises determining the lateral displacement of the vehicle in the vehicle combination when entering the curve, based on the predicted angular movement of the trailer, in order to keep all parts of the vehicle combination within the driving lane while passing the curve. The method also comprises adjusting the lateral displacement of the vehicle when entering the curve, according to the determined lateral displacement.

According to a second aspect of the invention, this objective is achieved by a control arrangement in a vehicle of a vehicle combination comprising a vehicle and a trailer articulatedly attached to the vehicle at a coupling point. The control arrangement aims at providing lateral displacement of the vehicle combination during passage of a curve. The control arrangement is configured to detect the curve ahead of the vehicle combination. Further, the control arrangement is configured to determine a critical passage of the detected curve. The control arrangement is also configured to determine width of a driving lane at the detected curve. In further addition, the control arrangement is configured to predict angular movement of the trailer relative the vehicle during passage of the detected curve at the critical curve passage, based on a mathematical model. The control arrangement is furthermore configured to determine the lateral displacement of the vehicle in the vehicle combination when entering the curve, based on the predicted angular movement of the trailer, in order to keep all parts of the vehicle combination within the driving lane while passing the curve. Also, the control arrangement is configured to adjust the lateral displacement of the vehicle when entering the curve, according to the determined lateral displacement.

Thanks to the described aspects, by detecting an approaching curve, determining the shortest curvature and width thereof and predicting the angular movement of the trailer, a lateral displacement of the vehicle combination when entering the curve may be determined, in order to not let any part of the vehicle combination exceed the driving lane. Thereby, a functionality is achieved which may assist the driver in adding momentum on the steering wheel when required.

By considering the position of the trailer when predicting angular movement of the trailer relative the vehicle during passage of the detected curve does not involve complex modelling and is therefore very computationally simple. This is desired when running on limited processor capacity, which is the reality for vehicle electronic control units today. Thus, enhanced curve taking is achieved.

Other advantages and additional novel features will become apparent from the subsequent detailed description.

FIGURES Embodiments of the invention will now be described in further detail with reference to the accompanying figures, in which: Figure 1 illustrates a vehicle combination according to an embodiment of the invention; Figure 2A illustrates an example of a traffic scenario and an embodiment of the invention; Figure 2B illustrates an example of a traffic scenario and an embodiment of the invention; Figure 3 illustrates an example of a vehicle interior, according to an embodiment of the invention; Figure 4 is a flow chart illustrating an embodiment of the method; Figure 5 is an illustration depicting a system according to an embodiment.

DETAILED DESCRIPTION Embodiments of the invention described herein are defined as a method and a control arrangement, which may be put into practice in the embodiments described below. These embodiments may, however, be exemplified and realised in many different forms and are not to be limited to the examples set forth herein; rather, these illustrative examples of embodiments are provided so that this disclosure will be thorough and complete.

Still other objects and features may become apparent from the following detailed description, considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the herein disclosed embodiments, for which reference is to be made to the appended claims. Further, the drawings are not necessarily drawn to scale and, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

Figure 1 illustrates a vehicle combination 100. The vehicle combination 100 comprises a vehicle 101 and a trailer 102 articulatedly attached to the vehicle 101 at a coupling point 120. The vehicle combination 100 is driving in a driving direction 105 on a driving lane 110. The vehicle 101 may also be referred to as a tractor.

The vehicle combination 100 may comprise e.g. a semi-trailer truck with a connected trailer or similar arrangement.

The vehicle 101 and / or the vehicle combination 100 may be manned, or autonomous in different embodiments.

In order to operate the vehicle combination 100 through a curve automatically, or autonomously, in a safe manner, an accurate assessment of the trailer position of the vehicle 101 may be required.

A curve of a road bends in one direction to bring a gradual change of direction. In order to provide predictability for the driver, a smooth and even bending in one direction is made. The curve may be circular, having the same radius throughout the bending and comprising a single arc of circle. Alternatively, the curve may be a spiral curve. The spiral curve is a geometric feature that can be added on to a regular circular curve. The spiral provides a gradual transition from moving in a straight line to moving in a curve around a point (or vice-verse). At some point in the curve, independently of the construction of the curve, there will be a point or segment where the radius of the curvature is the shortest, i.e. where the bending of the curve reaches its maximum. This is the most critical part for the vehicle combination 100 when passing the curve, as there is a risk that some part of the vehicle combination 100, in particular the trailer 102, drive off the lane 110.

A model may be used for predicting the behaviour of the trailer 102 being attached to the vehicle 101 in a future turn. A maximum tow angle may be used in the model, in some embodiments. Such model should preferably be independent on the trailer properties, as one single tow vehicle is generally used with different trailers.

To solve these deficiencies associated with curve taking, this disclosure introduces a method that uses a trailer model. In the model one or more unknown model parameters are updated based on observations e.g. from a sensor such as a radar or camera. In one example embodiment, the model sees the trailer 102 as a pendulum that starts in the trailer's centre of rotation and ends in the coupling point 120 between the trailer 102 and the tractor 101. Since the velocity of the connection point 120 is known, it is possible to calculate the rotational or angular speed of the trailer 102 and thus its angle relative to the tractor 101. Side slip for the trailer axle may be neglected, which is a key to modelling the trailer 102 using a pendulum model.

The coupling point 120, which may also be referred to as the articulation point, is the physical coupling between the vehicle 101 and the trailer 102. For example, the coupling point 120 comprises a coupling of a fifth-wheel type.

Figure 2A illustrates a scenario with the vehicle combination 100 of Figure 1 as regarded from above, approaching a curve 200, ahead in the driving direction 105.

A width 230 of the driving lane 110 and / or a lane centre 210 of the driving lane 110 may be determined and a lateral displacement 240 of the vehicle combination 100 may be determined at a moment before the vehicle combination 100 enters the curve 200.

The lateral displacement 240 of the vehicle combination 100 may be made in order not to allow any part of the vehicle combination 100 to exceed the driving lane 110, based on a mathematical model.

By using a mathematical model describing the angular movement of the trailer/s 102 relative the vehicle 101 the steady-state solution can be obtained for a given situation. The relation Image available on "Original document" describes the angular velocity y(t) of the trailer 102. It is transformed via a Laplace transformation as s * ?(s) = G(s) where the steady-state solution is obtained as ?(0), i.e. s = 0. By comparing it to the road ahead the trailer’s positioning in the lane 110 is obtained. In Figure 2A this position is determined by the distance 240 to the lane centre 210, at the point where the centre of the trailer 102 is farthest away from the centre of the lane 210.

The mathematical model may be based on the approximation that the coupling point 120 has a uniform circular motion with regards to a rotation centre of the trailer 102. This is an example of one simplified way of modelling the trailer 102.

The velocity in longitudinal and lateral direction of the coupling point 120 in the vehicle’s coordinate system is typically known to the vehicle 101. Hence, the rotational speed of the trailer 102 may be calculated using a pendulum approximation. Furthermore, side slip for trailer rear axle may be neglected, which is a key to approximating the trailer 102 as a pendulum. The side slip angle is the angle between the trailer’s back axle and trailers actual movement direction.

The mathematical model assumes that the circular motion of the trailer 102 around the trailer’s rotation centre is constant. This condition is fulfilled in a steady state curve. A steady state curve refers to a condition during the curve 200 when the entire vehicle combination 100 is in a steady state. This condition will typically occur when the yaw-rate of the vehicle 101 has been constant for some time, e.g. a few seconds. Then the yaw-rate of the trailer 102 will typically also stabilise. Hence, in the steady state curve the tow angle is constant. Hence, in a steady state curve the trailer 102 has reached one of the outer positions, if the trailer movement is modelled as a pendulum movement.

It is not certain that such a steady state is reached in every curve. However, the model assumes that an estimate of what the angle would have been if a steady state was reached at the sharpest point of the curve 200, corresponds to or exceeds what the actual angle will be in that point. Hence, the model will give a maximum value for the angle, which is a value that may be usable for controlling the vehicle 101.

In an example of the mathematical model, the change in the angle between a longitudinal centre line of the trailer 102 and the longitudinal centre line of the vehicle 101 may be calculated, as the yaw-rate of the vehicle 101 and the trailer 102 is known. From the equation of a particles motion in a constant curve, i.e. when the tow angle is constant, the lateral velocity may be calculated.

The lateral velocity in the coordinate system of the trailer 102 may then be transposed to the coordinate system of the vehicle 101 using standard formulas. Then, the angular speed of the trailer 102 may be computed, neglecting side slip in assumption of low lateral accelerations.

According to some embodiments, the prediction comprises analysing the curvature of the future path of the vehicle combination 100, determining the position of the vehicle combination 100 in a maximum curvature of the future path, and calculating, using the mathematical model, an angle between a longitudinal centre line of the trailer 102 and the longitudinal centre line of the vehicle 101, at the determined position. Hence, the position of the trailer 102 during passage of the curve 200 may be predicted.

Figure 2B illustrates the scene of Figure 2A, at a slightly later moment in time, when the vehicle combination 100 has reached a point in the curve 200 with the shortest curvature. This position is the most critical when passing the curve 200, as there is a risk that the trailer 102 exceeds the borders of the driving lane 110. It is important to keep all parts of the vehicle combination 100 within the driving lane 110 in order to avoid accidents.

The planned position of the vehicle combination 100 may thus be adjusted prior to the curve 200 in order to reduce the distance 250, in Figure 2B this corresponds to the vehicle 101 being left positioned in the curve 200 before entering the curve 200, instead of being in the centre 210.

The lateral position adjustment for articulated vehicles 100 increases the safety of a Lane Keep Assist function as it ensures remaining in the lane 110. It also adds to heightened driver comfort since the function corresponds better with manual driving, where the driver typically places the vehicle combination 100 in the outer part of a curve 200 to not cut it. This results in a function that will to a higher extent assist the driver with additional momentum on the steering wheel when it is desired.

This method of considering the position of the trailer 102 is advantageous to other already existing algorithms, since it does not involve complex modelling and is therefore very computationally simple. This is desired when running on limited processor capacity, which is the reality for vehicle electronic control units today.

Figure 3 illustrates an example of a vehicle interior of the vehicle 101 in the vehicle combination 100.

The vehicle 100 comprises a control arrangement 310 for lateral displacement 240 of the vehicle combination 100 during passage of a curve 200. The control arrangement 310 may comprise e.g. an Electronic Control Unit (ECU). The control arrangement 310 may comprise a digital computer that controls one or more electrical systems, or electrical sub systems, of the vehicle 101, based on e.g. information read from sensors placed at various parts and in different components of the vehicle 101 and / or the trailer 102. ECU is a generic term that often is used in automotive electronics, for any embedded system that controls one or more of the electrical system or sub systems in the vehicle 101. The control arrangement 310 may be particularly designated to implement an Advanced Driver Assistance System (ADAS) function, such as Line Keep Assist or similar. However, it must be appreciated that the vehicle 101 typically may comprise a plurality of ECUs. According to some embodiments, the control arrangement 310 comprises more than one ECU.

The control arrangement 310 may detect that the vehicle 101 is approaching a curve 200, e.g. by determining geographical position and driving direction 105 of the vehicle 101 and comparing the determined geographical position with map data; or by detecting the ahead curve 200 via a sensor 350 in the vehicle 101.

Furthermore, the vehicle 101 may comprise a database 320. The database 320 may comprise map data, and / or information about curves 200 on the road, such as curvature.

The geographical position of the vehicle 101 may be determined by the positioning unit 330 in the vehicle 101, which may be based on a satellite navigation system such as the Navigation Signal Timing and Ranging (Navstar) Global Positioning System (GPS), Differential GPS (DGPS), Galileo, GLONASS, or the like.

The geographical position of the positioning unit 330, (and thereby also of the vehicle 101) may be made continuously with a certain predetermined or configurable time intervals according to various embodiments.

Positioning by satellite navigation is based on distance measurement using triangulation from a number of satellites 340a, 340b, 340c, 340d. In this example, four satellites 340a, 340b, 340c, 340d are depicted, but this is merely an example. More than four satellites 340a, 340b, 340c, 340d may be used for enhancing the precision, or for creating redundancy. The satellites 340a, 340b, 340c, 340d continuously transmit information about time and date (for example, in coded form), identity (which satellite 340a, 340b, 340c, 340d that broadcasts), status, and where the satellite 340a, 340b, 340c, 340d are situated at any given time. The GPS satellites 340a, 340b, 340c, 340d sends information encoded with different codes, for example, but not necessarily based on Code Division Multiple Access (CDMA). This allows information from an individual satellite 340a, 340b, 340c, 340d distinguished from the others' information, based on a unique code for each respective satellite 340a, 340b, 340c, 340d. This information can then be transmitted to be received by the appropriately adapted positioning device comprised in the vehicle 101.

Distance measurement can according to some embodiments comprise measuring the difference in the time it takes for each respective satellite signal transmitted by the respective satellites 340a, 340b, 340c, 340d to reach the positioning unit 330. As the radio signals travel at the speed of light, the distance to the respective satellite 340a, 340b, 340c, 340d may be computed by measuring the signal propagation time.

The positions of the satellites 340a, 340b, 340c, 340d are known, as they continuously are monitored by approximately 15-30 ground stations located mainly along and near the earth's equator. Thereby the geographical position, i.e. latitude and longitude, of the vehicle 100 may be calculated by determining the distance to at least three satellites 340a, 340b, 340c, 340d through triangulation. For determination of altitude, signals from four satellites 340a, 340b, 340c, 340d may be used according to some embodiments.

The geographical position of the vehicle 100 may alternatively be determined, e.g. by having transponders positioned at known positions around the route of the vehicle 100 and a dedicated sensor in the vehicle 100, for recognising the transponders and thereby determining the position; by detecting and recognising Wi-Fi networks (Wi-Fi networks along the route may be mapped with certain respective geographical positions in a database); by receiving a Bluetooth beaconing signal, associated with a geographical position, or other signal signatures of wireless signals such as e.g. by triangulation of signals emitted by a plurality of fixed base stations with known geographical positions.

Having determined the geographical position of the positioning unit 330 (or in another way), a check may be made in the database 320 to determine whether the vehicle 101 is approaching a curve 200.

Alternatively, the curve 200 may be detected by the sensor 350 in the vehicle 101, directed in the driving direction 105. The sensor 350 may comprise e.g. a camera, a stereo camera, an infrared camera, a video camera, a radar, a lidar, an ultrasound device, a time-of-flight camera, or similar device, in different embodiments.

In the illustrated embodiment, which is merely an arbitrary example, the optional forwardly directed sensor 350 may be situated e.g. at the front of the vehicle 101, behind the windscreen of the vehicle 101.

Mounting the forwardly directed sensor 350 behind the windshield have some advantages compared to externally mounted camera systems. These advantages include the possibility to use windshield wipers for cleaning and using the light from headlights to illuminate objects in the camera’s field of view. It is also protected from dirt, snow, rain and to some extent also from damage, vandalism and/ or theft. Such sensor 350 may also be used for a variety of other tasks, such as detecting an in-front object or vehicle, detecting road signs, detecting road lane markings, for estimating distance to an in-front vehicle, etc.

Sensor signals of the sensor 350 may be interpreted by image recognition/ computer vision and object recognition, for recognising the curve 200.

Computer vision is a technical field comprising methods for acquiring, processing, analysing, and understanding images and, in general, high-dimensional data from the real world in order to produce numerical or symbolic information. A theme in the development of this field has been to duplicate the abilities of human vision by electronically perceiving and understanding an image. Understanding in this context means the transformation of visual images (the input of retina) into descriptions of world that can interface with other thought processes and elicit appropriate action. This image understanding can be seen as the disentangling of symbolic information from image data using models constructed with the aid of geometry, physics, statistics, and learning theory. Computer vision may also be described as the enterprise of automating and integrating a wide range of processes and representations for vision perception.

The detection of the ahead curve 200 may then trigger initiation of the method for lateral displacement 240 of a vehicle combination 100 as will be further explained and discussed in conjunction with presentation of Figure 4.

The control arrangement 310 may communicate with the other vehicle internal units such as the database 320, the positioning device 330, and / or the sensor 350 via e.g. a communication bus. The communication bus may comprise e.g. a Controller Area Network (CAN) bus, a Media Oriented Systems Transport (MOST) bus, or similar. However, the datalink may alternatively be made over a wireless connection comprising, or at least be inspired by any wireless communication technology such as e.g. Wi-Fi, Bluetooth, etc.

Figure 4 illustrates an example of a method 400 according to an embodiment. The flow chart in Figure 4 shows the method 400 for use in a vehicle 100. The method 400 aims at providing lateral displacement 240 of a vehicle combination 100 comprising a vehicle 101 and a trailer 102 articulatedly attached to the vehicle 101 at a coupling point 120, during passage of a curve 200.

In order to correctly be able to displace the vehicle combination 100, for providing vehicle diagnosis, the method 400 may comprise a number of steps 401-407. However, some of these steps 401-407 may be performed in various alternative manners. Some method steps may only be performed in some optional embodiments; such as e.g. step 405. Further, the described steps 401 -407 may be performed in a somewhat different chronological order than the numbering suggests. The method 400 may comprise the subsequent steps: Step 401 comprises detecting the curve 200 ahead of the vehicle combination 100.

The detection of the curve 200 ahead of the vehicle combination 100, may be performed based on map data in a database 320, at a geographical position ahead of the vehicle combination 100, or sensor data of a forwardly directed sensor 350 of the vehicle 101.

An advantage of using map data in combination with geographical position of the vehicle combination 100 in comparison with sensor detection of the curve 200 is that the ahead curve 200 may be obscured, e.g. by another vehicle (e.g. during platooning) or other various road side structures or vegetation. Also, the ahead curve 200 may be detected well in advance before the vehicle combination 100 arrives at the beginning of the curve 200, thereby enabling a slow and smooth lateral positioning of the vehicle 101.

The detection of the ahead curve 200 may alternatively also be made by receiving curve detection information from an ahead driving vehicle via vehicle-to-vehicle communication, for example when the vehicles are driving in a platoon formation in the same direction; or alternatively from an oncoming vehicle.

Step 402 comprises determining a critical passage of the detected 401 curve 200.

The most critical passage of the curve 200 is where the curve bending is at maximum, i.e. the part of the curve 200 having the shortest radius of curvature in case of a spiral curve. If the curve 200 has a constant curvature, it also has one single radius. The most critical part of the curve 200 then becomes the middle of the curve, or the curve segment which is most remote from the beginning and the end of the curve 200, i. e. from any straight road segments before/ after the curve 200.

The determination of the critical curve passage, may be performed based on map data at a geographical position ahead of the vehicle combination 100, or sensor data.

Step 403 comprises determining width 230 of a driving lane 110 at the detected 401 curve 200.

The determination of width 230 of the driving lane 110 at the detected 401 curve 200 may be performed based on map data at a geographical position ahead of the vehicle combination 100; or sensor data.

Step 404 comprises predicting angular movement of the trailer 102 relative the vehicle 101 during passage of the detected 401 curve 200 at the critical curve passage, based on a mathematical model.

The mathematical model may be based on a steady state solution of the angle of the trailer 102 in relation to the vehicle 101, when passing the curve 200.

Typically, the curvature of the curve 200 gradually increases up to a maximum bending, which is the most critical part of the curve 200 in the meaning that there is risk that a part of the trailer 102 drives off the lane 110, where after the curve 200 straightens out.

Step 405, which may be comprised only in some particular embodiments, comprises determining a lane centre 210 of the driving lane 110 at the detected 401 curve 200.

Determining the lane centre 210 may be helpful in laterally placing the vehicle combination 100 with an as small lateral deviation from the lane centre 210 as possible, thereby earning a margin to the driving lane borders.

Step 406 comprises determining the lateral displacement 240 of the vehicle 101 in the vehicle combination 100 when entering the curve 200, based on the predicted 404 angular movement of the trailer 102, in order to keep all parts of the vehicle combination 100 within the driving lane 110 while passing the curve 200.

In some embodiments wherein step 405 has been performed, the lateral displacement 240 of the vehicle combination 100 may be determined in relation to the determined 405 lane centre 210.

The lateral displacement 240 of the vehicle 101 may be determined in order to minimise a weighted sum of a lateral displacement 250 of the vehicle combination 100 when passing the curve 200.

Thereby, a margin to the borders of the driving lane 110 is kept, both at the passage of the most critical part of the curve 200, and at the beginning of the curve 200, leading to safer driving.

Step 407 comprises adjusting the lateral displacement 240 of the vehicle 101 when entering the curve 200, according to the determined 406 lateral displacement 240.

Thereby, by displacing the vehicle combination 100 before entering a curve 200 instead of placing the vehicle combination 100 at the centre 210 of the driving lane 110, it is avoided that the vehicle combination 100, or some part thereof, exceeds the driving lane 110.

Figure 5 illustrates an embodiment of a system 500 in a vehicle 100 for vehicle self-diagnosis by visual inspection. The system 500 may perform at least some of the previously described method steps 401-407 according to the method 400 described above and illustrated in Figure 4.

The system 500 comprises at least one control arrangement 310 in the vehicle 100, for lateral displacement 240 of the vehicle combination 100 during passage of a curve 200.

The control arrangement 310 is configured to detect the curve 200 ahead of the vehicle combination 100. Further, the control arrangement 310 is also configured to determine a critical passage of the detected curve 200. The control arrangement 310 is also configured to determine width 230 of a driving lane 110 at the detected curve 200. Additionally, the control arrangement 310 is further configured to predict angular movement of the trailer 102 relative the vehicle 101 during passage of the detected curve 200 at the critical curve passage, based on a mathematical model. Furthermore, the control arrangement 310 is configured to determine the lateral displacement 240 of the vehicle 101 in the vehicle combination 100 when entering the curve 200, based on the predicted angular movement of the trailer 102, in order to keep all parts of the vehicle combination 100 within the driving lane 110 while passing the curve 200. Also, in addition, the control arrangement 310 is configured to adjust the lateral displacement 240 of the vehicle 101 when entering the curve 200, according to the determined lateral displacement 240.

In some embodiments, the control arrangement 310 may be configured to determine a lane centre 210 of the driving lane 110 at the detected curve 200. Also, the control arrangement 310 may be configured to determine the lateral displacement 240 of the vehicle combination 100 in relation to the determined lane centre 210.

The control arrangement 310 may in some embodiments be configured to determine the lateral displacement 240 of the vehicle 101 in order to minimise a weighted sum of a lateral displacement 250 of the vehicle combination 100 when passing the curve 200.

The control arrangement 310 may also in some embodiments be configured to compute the mathematical model based on a steady state solution of the angle of the trailer 102 in relation to the vehicle 101, when passing the curve 200.

In some embodiments, the control arrangement 310 may be configured to detect the curve 200 ahead of the vehicle combination 100; and / or determine the shortest radius of curvature of the detected 401 curve 200; and / or determine width of the driving lane 110 at the detected curve 200 based on map data at a geographical position ahead of the vehicle combination 100; or alternatively on sensor data.

Further, the system 500 also may comprise at least one sensor 350 of the vehicle 101, in some embodiments. The system also, or alternatively, may comprise a positioning device 330 and/ or a database 320.

The control arrangement 310 comprises a receiving circuit 510 configured for receiving a signal from the sensor 350; from the positioning device 330 and / or from the database 320.

Further, the control arrangement 310 comprises a processing circuitry 520 configured for performing at least some steps 401-407 of the above described method 400, according to some embodiments.

Such processing circuitry 520 may comprise one or more instances of a processing circuit, i.e. a Central Processing Unit (CPU), a processing unit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression “processing circuitry” may thus comprise a plurality of processing circuits, such as, e.g., any, some or all of the ones enumerated above.

Furthermore, the control arrangement 310 may comprise a memory 525 in some embodiments. The optional memory 525 may comprise a physical device utilised to store data or programs, i.e., sequences of instructions, on a temporary or permanent basis. According to some embodiments, the memory 525 may comprise integrated circuits comprising siliconbased transistors. The memory 525 may comprise e.g. a memory card, a flash memory, a USB memory, a hard disc, or another similar volatile or non-volatile storage unit for storing data such as e.g. ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc. in different embodiments.

Further, the control arrangement 310 may comprise a signal transmitter 530 in some embodiments. The signal transmitter 530 may be configured for transmitting a signal to e.g. the steering control of the vehicle 101.

The above described steps 401-407 to be performed in the vehicle combination 100 may be implemented through the one or more processing circuitry 520 within the control arrangement 310, together with computer program product for performing at least some of the functions of the steps 401-407. Thus a computer program product, comprising instructions for performing the steps 401-407 in the control arrangement 310 may perform the method 400 comprising at least some of the steps 401-407 for lateral displacement 240 of the vehicle combination 100 during passage of a curve 200, when the computer program is loaded into the one or more processing circuitries 520 of the control arrangement 310.

Further, some embodiments of the invention may comprise a vehicle 100, comprising the control arrangement 310, for lateral displacement 240 of the vehicle combination 100 during passage of a curve 200, according to at least some of the steps 401-407.

The computer program product mentioned above may be provided for instance in the form of a data carrier carrying computer program code for performing at least some of the steps 401-407 according to some embodiments when being loaded into the one or more processing circuitries 520 of the control arrangement 310. The data carrier may be, e.g., a hard disk, a CD ROM disc, a memory stick, an optical storage device, a magnetic storage device or any other appropriate medium such as a disk or tape that may hold machine readable data in a non-transitory manner. The computer program product may furthermore be provided as computer program code on a server and downloaded to the control arrangement 310 remotely, e.g., over an Internet or an intranet connection.

The terminology used in the description of the embodiments as illustrated in the accompanying drawings is not intended to be limiting of the described method 400; the control arrangement 310; the computer program; the system 500 and / or the vehicle 101 of a vehicle combination 100 comprising the vehicle 101 and a trailer 102. Various changes, substitutions and / or alterations may be made, without departing from invention embodiments as defined by the appended claims.

As used herein, the term "and/ or" comprises any and all combinations of one or more of the associated listed items. The term “or” as used herein, is to be interpreted as a mathematical OR, i.e., as an inclusive disjunction; not as a mathematical exclusive OR (XOR), unless expressly stated otherwise. In addition, the singular forms "a", "an" and "the" are to be interpreted as “at least one”, thus also possibly comprising a plurality of entities of the same kind, unless expressly stated otherwise. It will be further understood that the terms "includes", "comprises", "including" and / or "comprising", specifies the presence of stated features, actions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, elements, components, and / or groups thereof. A single unit such as e.g. a processor may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/ distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms such as via Internet or other wired or wireless communication system.

Claims

PATENT CLAIMS

1. A method (400) for lateral displacement (240) of a vehicle combination (100) comprising a vehicle (101) and a trailer (102) articulatedly attached to the vehicle (101) at a coupling point (120), during passage of a curve (200); wherein the method (400) comprises: detecting (401) the curve (200) ahead of the vehicle combination (100); determining (402) a critical part of the detected (401) curve (200); determining (403) width (230) of a driving lane (110) at the detected (401) curve (200); predicting (404) angular movement of the trailer (102) relative the vehicle (101) during passage of the detected (401) curve (200) at the determined (402) critical part, based on a mathematical model; determining (406) the lateral displacement (240) of the vehicle (101) in the vehicle combination (100) when entering the curve (200), based on the predicted (404) angular movement of the trailer (102), in order to keep all parts of the vehicle combination (100) within the driving lane (110) while passing the curve (200); and adjusting (407) the lateral displacement (240) of the vehicle (101) when entering the curve (200), according to the determined (406) lateral displacement (240).

2. The method (400) according to claim 1, further comprising: determining (405) a lane centre (210) of the driving lane (110) at the detected (401) curve (200); and wherein the lateral displacement (240) of the vehicle combination (100) is determined (406) in relation to the determined (405) lane centre (210).

3. The method (400) according to any one of claim 1 or claim 2, wherein the lateral displacement (240) of the vehicle (101) is determined (406) in order to minimise a weighted sum of a lateral displacement (250) of the vehicle combination (100) when passing the curve (200).

4. The method (400) according to any one of claims 1-3, wherein the mathematical model is based on a steady state solution of the angle of the trailer (102) in relation to the vehicle (101), when passing the curve (200).

5. The method (400) according to any one of claims 1-4, wherein the detection (401) of the curve (200) ahead of the vehicle combination (100), the determination (402) of the critical part of the detected (401) curve (200), or the determination (403) of width (230) of the driving lane (110) at the detected (401) curve (200) is performed based on map data at a geographical position ahead of the vehicle combination (100); or sensor data.

6. A control arrangement (310) in a vehicle (101) of a vehicle combination (100) comprising a vehicle (101) and a trailer (102) articulatedly attached to the vehicle (101) at a coupling point (120), for lateral displacement (240) of the vehicle combination (100) during passage of a curve (200); wherein the control arrangement (310) is configured to: detect the curve (200) ahead of the vehicle combination (100); determine a critical part of the detected (401) curve (200); determine width (230) of a driving lane (110) at the detected curve (200); predict angular movement of the trailer (102) relative the vehicle (101) during passage of the detected curve (200) at the critical curve passage, based on a mathematical model; determine the lateral displacement (240) of the vehicle (101) in the vehicle combination (100) when entering the curve (200), based on the predicted angular movement of the trailer (102), in order to keep all parts of the vehicle combination (100) within the driving lane (110) while passing the curve (200); and adjust the lateral displacement (240) of the vehicle (101) when entering the curve (200), according to the determined lateral displacement (240).

7. The control arrangement (310) according to claim 6, further configured to: determine a lane centre (210) of the driving lane (110) at the detected curve (200); and also configured to: determine the lateral displacement (240) of the vehicle combination (100) in relation to the determined lane centre (210).

8. The control arrangement (310) according to any one of claim 6 or claim 7, further configured to determine the lateral displacement (240) of the vehicle (101) in order to minimise a weighted sum of a lateral displacement (250) of the vehicle combination (100) when passing the curve (200).

9. The control arrangement (310) according to any one of claims 6-8, wherein the mathematical model is based on a steady state solution of the angle of the trailer (102) in relation to the vehicle (101), when passing the curve (200).

10. The control arrangement (310) according to any one of claims 6-9, further configured to: detect the curve (200) ahead of the vehicle combination (100); determine the critical part of the detected curve (200); or determine width (230) of the driving lane (110) at the detected curve (200); based on map data at a geographical position ahead of the vehicle combination (100); or sensor data.

11. A computer program comprising program code for performing a method (400) according to any of claims 1 -5 when the computer program is executed in a processor (420) in a control arrangement (310), according to any of claims 6-10.

12. A vehicle (101) of a vehicle combination (100) comprising the vehicle (101) and a trailer (102), further comprising a control arrangement (310) according to any one of claims 6-10.