TECHNICAL FIELD

This document relates to a method and a control arrangement for a tractor. More particularly, a method and a control arrangement are described, for estimating maximum height of a vehicle combination comprising the tractor and a trailer and perform an action based on the estimated height.

BACKGROUND

When composing and/ or driving a vehicle combination, comprising a tractor and a trailer, the driver (or autonomous logic of the tractor) may not know the height of the trailer.

On the tractor itself, sensors and configuration parameters can be used to identify the critical height (meaning the highest part) of the tractor itself. The problem comes when attaching an articulated trailer to the tractor.

When the vehicle combination comprises a semi-trailer attached to the tractor, the critical height of the vehicle combination may change depending e.g. load of the trailer, on road inclination and the suspension level of the tractor unit. Some modern semi-trailers may communicate the configuration (size and position of axles, kingpin etc.) but does not measure the inclination angle relative to the ground or tractor unit. However, the reliability/ safety of using only pre-programmed trailer dimension information to authorise autonomous driving will not be enough for safety purposes.

Heavily loaded semi-trailers may bend/ deform slightly from the forces of the cargo and should no longer be represented as a “rectangular box” seen from the side. This deformation is very hard to measure with sensors on the trailer but will likely be important when calculating critical height.

Document US20180045823 discloses a trailer detection system using e.g. a rear-facing camera and radar to determine a trailer-height (36). The system is able to determine the position of viewable features, as in the top-horizontal edge (48) of the trailer.

The solution of US20180045823 is based on usage of two dedicated sensors (radar + camera), which are able to detect the front end of the trailer. No solution is suggested for estimating height of the trailer when the sensors cannot detect all parts of the trailer/ the top section of the trailer. The solution in document US20180045823 only concerns a car with an attached trailer, not a tractor pulling a semi-trailer, where the top edge of the semi-trailer is not possible to detect with the sensor. The problem of determining trailer height becomes more complicated when using a semi-trailer or an articulated trailer in combination with a tractor, due to the differences in dimensions between car/ tractor, and that the critical height of the trailer might change due to road inclination and the suspension level of the truck. Further, due to deformation of the semi-trailer and large variety of shape of the upper part of semi-trailers, it can be difficult to measure the critical height of the trailer by sensors on-board the trailer.

It would also be desired to instead find a solution not using dedicated sensors only/ mainly for the purpose of determining height of the trailer.

It would thus be desired to improve height estimation of a trailer in a vehicle combination.

SUMMARY

It is therefore an object of this invention to solve at least some of the above problems and improve traffic safety by estimating maximum height of a trailer in a vehicle combination.

According to a first aspect, this objective is achieved by a method in a control arrangement of a tractor in a vehicle combination comprising the tractor and a trailer. The method comprises the step of performing an action based on an estimated height over a road surface of a highest point of an extrapolated section of an upper edge of the trailer along a longitudinal extension of the trailer. The section of the upper edge of the trailer is extrapolated based on sensor detection of a shape of a sensor-visible section of the upper edge of the trailer and sensor data indicative of a position in height of at least one point of the sensor-visible section.

According to a second aspect, this objective is achieved by a control arrangement for a tractor in a vehicle combination. The vehicle combination comprises the tractor and a trailer. The control arrangement is configured to trigger performance of an action based on an estimated height over a road surface of a highest point of an extrapolated section of an upper edge of the trailer along a longitudinal extension of the trailer. The section of the upper edge of the trailer is extrapolated based on sensor detection of a shape of a sensor-visible section of the upper edge of the trailer and sensor data indicative of a position in height of at least one point of the sensor-visible section, obtained from a rearward looking sensor of the tractor.

Thanks to described aspects, it will be possible to finish a planned route safely and on time, without risk of collision with a crossing bridge or similar height restriction of the road. By extrapolating the shape of the trailer rooftop, based on the shape of the part of the rooftop that is visible for the rearward looking sensor of the tractor, it becomes possible to estimate shape/ deformation of the trailer, and in particular where the highest point of the trailer is situated and also estimate height of the extrapolated highest point over the road of the trailer, also when the highest point of the trailer rooftop is not possible to detect for the rearward looking sensor of the tractor. Thus, increased traffic safety is achieved.

The presented solution may be realised without dedicated additional sensors, since it enables use of the sensors already provided on the tractor for other purposes. Thereby, resources may be saved, both in form of hardware and, depending on placement of dedicated sensors, reduced air resistance. A further advantage is that the height of the trailer may be estimated without increased sensor costs.

The vehicle combination will be enabled to avoid inconveniences on the road, such as accidents, or the inability to go through a tunnel or under a crossing bridge on a selected route. Therefore, time and energy are saved by (re-)planning the vehicle route carefully with regard to the maximum allowed vehicle height of the route, based on the height dimensions of the trailer. Also, other road users will be kept safe as it is ascertained that the vehicle combination meets the height criteria of the preferred/ selected route towards the destination.

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 A illustrates a tractor and a trailer according to an embodiment of the invention, which may be combined, thereby forming a vehicle combination;

Figure 1B illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention, wherein the trailer has an inclination in relation to the road;

Figure 1C illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention, wherein the trailer is disformed;

Figure 1 D illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention, wherein the trailer has an atypical/ unconventional shape;

Figure 1 E illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention, passing a hill top;

Figure 1 F illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention, in a frontal view, wherein the trailer is laterally tilted in relation to the tractor;

Figure 2A illustrates a side view of a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention, wherein scope of a rearwards looking sensor is estimated;

Figure 2B illustrates a vehicle combination comprising a tractor and a trailer as regarded from above, according to an embodiment of the invention, wherein scope of rearwards looking sensors are estimated;

Figure 3A illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention in a side-view, wherein scope of a rightside rearwards looking sensor is estimated;

Figure 3B illustrates a vehicle combination comprising a tractor and a trailer according to an embodiment of the invention in a side-view, wherein scope of a left-side rearwards looking sensor is estimated;

Figure 3C illustrates a vehicle combination comprising a tractor and a trailer as regarded from above, according to an embodiment of the invention, wherein a sensor of an overtaking vehicle is measuring trailer dimensions;

Figure 4A illustrates an example of a vehicle interior of a tractor according to an embodiment, wherein the tractor is configured for satellite positioning;

Figure 4B illustrates an example of a vehicle interior of a tractor according to an embodiment, wherein the tractor comprises an image recognising sensor;

Figure 4C illustrates an example of a vehicle interior of a tractor according to an embodiment, wherein the tractor comprises a forward looking sensor;

Figure 5 is a flow chart illustrating an embodiment of a method for performing an action based on an estimated trailer height;

Figure 6 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 1A illustrates a scenario with a powered vehicle/ tractor 100a and a non-powered vehicle/ trailer/ semi-trailer 100b, which are enabled to form a vehicle combination 110, on a road 105. The vehicle combination 110 may comprise one or several trailers/ cargo carrying entities 100b, such as e.g. 2, 3, etc.

Subsequently, the term “trailer” is consistently used for denominating the, typically, non-pow- ered vehicle/ trailer/ semi-trailer 100b. Most illustrations herein are rather depicting a semitrailer than a trailer, as semi-trailers are by far more frequently used in long haulage vehicle combinations. The presented solution may be utilised with particular advantages when the vehicle combination 110 is formed with a semi-trailer. Thus, the term “trailer”, in the current context, is to be understood as semi-trailer and/ or trailer.

The tractor 100a may be driver controlled or driverless (i.e. autonomously controlled) in different embodiments. However, for enhanced reader understanding, the tractor 100a is subsequently described as having a driver.

The tractor 100a and the trailer 100b may exchange information over a datalink, e.g. via a bus such as e.g. a Controller Area Network (CAN) bus, a Media Oriented Systems Transport (MOST) bus, or similar; or via a wireless connection.

The tractor 100a comprises a coupling device 101. The trailer 100b comprises another coupling device 111 , configured to attach to the coupling device 101 of the tractor 100a. The vehicle combination 110 is composed by attaching the coupling device 101 of the tractor 100a with the coupling device 111 of the trailer 100b. The coupling devices 101 , 111 may be referred to as a towing coupling/ towing eye/ king pin.

The respective coupling devices 101 , 111 may have different heights; also, the tractor 100a and the trailer 100b may have been made by different manufacturers. The (driver of the) tractor 100a sometimes goes to pick-up and transport a trailer 100b with unknown features for the first time. The height of the highest point of the trailer 100b may then be unknown to the (driver of the) tractor 100a. Alternatively, the original height of the trailer 100b may be known to him/ her/ it (in case of autonomous tractor), but due to permanent or temporary deformation, the actual trailer height may be different.

In case the vehicle combination 110 is going to pass under a critical height construction such as a bridge, a tunnel, a garage door opening, etc., a serious accident may occur in case the (driver of the) tractor 100a is not aware of the current height of the highest point of the trailer 100b.

Otherwise, the consequences may be less dramatic, yet non-awareness of the current height of the highest point of the trailer 100b may result in incorrectly configured deflector, which in turn may cause an unnecessary increase in air resistance during high-speed transportation, and thus increased fuel/ electricity/ propellant consumption.

Figure 1 B illustrates an example of a vehicle combination 110 formed by a tractor 100a and a trailer 100b. The trailer 100b has been attached to the tractor 100a with an inclination a in relation to the road 105.

The inclination a of the trailer 100b causes the upper front end of the trailer 100b to form a maximum height point 120 of the vehicle combination 110, with a maximum height 130 over the road surface 105 (or whatever underneath the vehicle combination 110 is positioned on).

The reasons for the inclination a of the trailer 100b may be caused for example due to suspension level of the tractor 100a, and/ or due to a too high level of the coupling device 101 of the tractor 100a but may alternatively be caused by a temporal or permanent deformation of the trailer 100b.

The vehicle/ tractor 100a may comprise at least one rearward looking sensor, typically mounted at the rear-view mirror/s (or replacing the rear-view mirror/s). However, the main purpose of this/ these rearward looking sensor/s is to detect/ display overtaking vehicles, assist the driver when reversing the vehicle combination 110 etc., not to measure height of the trailer 100b. In case the maximum height point 120 of the trailer 100b is visible/ detectable by the rearward looking sensor/s situated at the rear-view mirror/s, the height of the trailer 100b could be estimated. But it is not always possible to detect an upper edge of the roof of the trailer 100b, and in particular not the maximum height point 120 and/ or the upper-forward short-side part of the roof of the trailer 100b with the rearward looking sensor/s.

A solution to this problem is to extrapolate a shape of the upper edge/ roof of the trailer 100b based on sensor detections of the part of the upper edge/ roof of the trailer 100b that is possible for the rearward looking sensor/s to detect. Then, the height 130 over the road surface 105 of the maximum height point 120 may be estimated.

Figure 1C illustrates yet an example of a vehicle combination 110 formed by a tractor 100a and a trailer 100b; or rather the trailer 100b of Figure 1A and/ or 1 B in a deformed shape.

The trailer 100b has been deformed, momentarily or permanently, due to influence of gravity of heavy cargo, and/ or possibly rough handling. Typically, a U-shape/ banana shape of the trailer 100b may be assumed. The deformation profile may be estimated e.g. by a model such as a polynomial function e.g. a second-grade polynomial function, third-grade polynomial function, clothoid and/ or by selecting a predetermined load case. Based thereupon, the position of the maximum height point 120 of the vehicle combination 110 may be identified, typically the upper front end of the trailer 100b. Thereafter, the maximum height 130 of the vehicle combination 110 over the road surface 105 may be estimated, based on the model.

Figure 1D illustrates an example of a vehicle combination 110 formed by a tractor 100a and a trailer 100b.

The trailer 100b may have a non-rectangular shape, for example an aerodynamic shape for reducing air-drag. The non-rectangular shape may alternatively be caused by non-intended deformation of the upper part of the trailer 100b.

The highest point 120 of the trailer 100b may not be situated at the most forward edge of the trailer 100b (i.e. “forward” in the normal travelling direction of the trailer 100b) but have another longitudinal position.

By extrapolating the shape of the upper edge of the trailer 100b along the longitudinal extension of the trailer 100b, based on sensor detection of a shape/ outline/ geometry of a sensor- visible section of the upper edge of the trailer 100b when connected to the tractor 100a in the vehicle combination 110, the highest point 120 of the trailer 100b may be determined and the height 130 over the road surface 105 of the highest point 120 may be estimated.

Figure 1 E illustrates yet an example of a vehicle combination 110 formed by a tractor 100a and a trailer 100b, driving on an inclined road segment 105, i.e. over a hill. Due to the inclined road 105, the maximum height point 120 may be identified as the upper front end of the trailer 100b, having the maximum height 130 over the road segment 105, in perpendicular direction in relation to the road 105 right under the maximum height point 120.

Figure 1 F illustrates another example of a vehicle combination 110 formed by a tractor 100a and a trailer 100b, as regarded from a frontal view.

The tractor 100a in the illustrated embodiment comprises a right-side rearward looking sensor 210a and a left-side rearward looking sensor 210b.

The respective position of the rearward looking sensors 210a, 210b in relation to the tractor geometry and also in relation to the road surface 105, i.e. the height position of the rearward looking sensors 210a, 210b is known. Thus, by determining a relative height position between the rearward looking sensor 210a, 210b and an arbitrary measurement target, the height of the measurement target over the road surface 105 could be determined.

Each one of the respective rearward looking sensors 210a, 210b may detect a respective shape of each sensor-visible section of the respective trailer side. The respective non-sen- sor-visible section of the respective trailer side may then be extrapolated. For example, a comparison between the respective extrapolated shapes/ heights of the right side/ left side of the roof of the trailer 100b could then be performed. It may then be detected where the highest point 120 is situated, typically on each the uttermost left side, or right side. The height 130 over the road surface 105 of the highest point 120 may thereby be estimated.

The different versions or examples of tractor 100a and trailers 100b illustrated in Figures 1A- 1 F may with advantage be combined with each other, i.e. the trailer 100b may be inclined in relation to the road surface 105 as illustrated in Figure 1 B while at the same time also being deformed as illustrated in Figure 1C and/ or having a non-rectangular shape as illustrated in Figure 1 D, which may be passing a hill as illustrated in Figure 1 E and/ or be tilted in lateral direction in relation to the underneath 105 and/ or the tractor 100a.

The tractor 100a and the trailer 100b, together forming the vehicle combination 110, have a vertical direction. The vertical direction is perpendicular to a flat horizontal support surface, such as the road 105, when the vehicle 100 is positioned in an upright use position with the wheels of the tractor 100a and trailer 100b resting on the flat horizontal support surface. In other words, the vertical direction of the tractor 100a and the trailer 100b is parallel to a surface normal of the flat horizontal support surface when the tractor 100a and the trailer 100b are positioned in the upright use position onto the flat horizontal support surface. Wheels of the tractor 100a and the trailer 100b are then abutting against the flat horizontal support surface, or road 105, and a respective chassis of the tractor 100a and the trailer 100b are forming a lower vertical termination of the vehicle combination 110.

The roof and/ or upper edge of the tractor 100a and/ or the trailer 100b are typically situated at a vertically extreme position, in opposed vertical direction to the respective chassis of the tractor 100a and the trailer 100b during intended or normal operation of the tractor 100a and/ or the trailer 100b, i.e. furthest from the support surface 105 in the vertical direction.

The tractor 100a and the trailer 100b also have a longitudinal direction. The longitudinal direction is parallel to the flat horizontal support surface when the tractor 100a and the trailer 100b are positioned in the upright use position onto the flat horizontal support surface. The longitudinal direction of the tractor 100a and the trailer 100b coincides with a forward and reverse driving direction of the vehicle combination 110. The tractor 100a and the trailer 100b also have a lateral direction. The lateral direction is perpendicular to the longitudinal direction and is perpendicular to the vertical direction of the tractor 100a and the trailer 100b. In other words, the lateral direction of the tractor 100a and the trailer 100b is parallel to a flat horizontal support surface when the tractor 100a and the trailer 100b are positioned in the upright use position onto the flat horizontal support surface/ road 105.

Figure 2A illustrates yet a vehicle combination 110 formed by a tractor 100a and a trailer 100b, driving on a road segment 105 in a driving direction 205.

Figure 2B illustrates the vehicle combination 110 of Figure 2A as regarded from above.

The tractor 100a comprises rearward looking sensors 210a, 210b for example integrated in, or alternatively replacing, a rearward looking mirror, situated on one or both lateral sides of the tractor 100a.

The main purpose of this/ these rearward looking sensor/s 210a, 210b is to detect/ display overtaking vehicles etc., not to measure height of the trailer 100b. The rearward looking sensor/s 210a, 210b normally cannot capture the frontal part of the trailer 100b (when the vehicle combination 110 is positioned in the driving direction 205), but merely a part of the respective lateral sides 200a, 200b of the trailer 100b.

The rearward looking sensors 210a, 210b is a device, module, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics within or outside the tractor 100a, such as a control arrangement of the tractor 100a/ vehicle combination 110. In this specific case, the sensor 210a, 210b should provide with information regarding the upper longitudinal edge of the trailer 100b.

The rearward looking sensor 210a, 210b may comprise e.g. a LIDAR, a camera, a stereo camera, an infrared camera, a video camera, a radar, an ultrasound device, a time-of-flight camera, or similar device, in different embodiments. Further, the rearward looking sensor 210a, 210b may comprise a plurality of different sensors of the same or different types that may perform measurements continuously, intermittently or periodically at a regular time interval.

The rearward looking sensor 210a, 210b does typically not have the front upper corner of the trailer 100b within its field of view. As the front upper corner of the trailer 100b often is the highest point of the vehicle combination 110, it is desired to estimate height of the front upper corner of the trailer 100b when direct measurements cannot be made with the rearward looking sensor 210a, 210b.

However, observations may be made by the rearward looking sensor 210a, 210b of at least some parts of the upper longitudinal edge of the trailer 100b. An extrapolation may then be made based on the observations, by approximating the upper longitudinal edge of the trailer 100b with a mathematical formula such as clothoid or a 3rd degree polynomial. Having found/ extrapolated the highest point 120 of the extrapolated upper longitudinal edge, maximum height 130 of the vehicle combination 110 may be calculated by calculating the height 130 over the road 105 of the highest point 120 of the extrapolated upper longitudinal edge.

In some embodiments, as illustrated in Figure 1 B, the model of the trailer 100b can also be linear with a height at some reference points and an elevation angle a in relation to the tractor 100a.

As mentioned above, the inclination of the road 105 can also be taken into consideration for estimating changes of the trailer elevation angle a on future positions on the road 105. However, this effect could also be neglected and replaced with a “worst case” trailer elevation angle a which may be considered when calculating the critical height 130.

Estimating the maximum height 130 of the critical highest point 120 of the vehicle combination 110 based on sensor measurements by the on-board sensor 210a, 210b is an important safety measure, in particular during driverless operation of tractor-trailer combinations. Thanks to the provided solution, manual/ human check of trailer height before departing a loading area may not be required.

The herein disclosed solution allows for a quick estimation of the maximum trailer height 130 for most types of trailers 100b, for example a semi-trailer with a more or less rectangular cross-section.

On manually driven vehicles, a warning system for low bridges/ height restricting structures intervening with the driving lane may be activated when the maximum height 130 of the vehicle combination 110 is too low for the vehicle combination 110 to pass. The information can also be used together with navigator data to replan the route to the destination, to avoid low bridges etc., during the travel.

For autonomous vehicles, this information may mainly be used for selecting another route to the destination, with less restrictive height restrictions.

The disclosed solution is expected to work for most trailers 100b, however some trailers 100b do not have any sharp upper corners (such as timber and car transports), and the provided solution may not always work under these circumstances. There are also trailers 100b with non-flat roofs where this method may be somewhat inaccurate. Such vehicle combinations 110 may require another or a somewhat modified method or a manual check/ confirmation before departing a loading area. Alternatively, the height 130 of the vehicle combination 110 may be measured by a vehicle external sensor, e.g. situated at the exit portal of the loading area, and the sensor measurements may be returned to the control arrangement of the tractor 100a for performing the method based on these measurements.

Figure 3A illustrates yet a vehicle combination 110 formed by a tractor 100a and a trailer 100b, driving on a road segment 105. A rearward looking sensor 210a of the tractor 100a may detect a sensor-visible section 310a of the upper edge 320a of a first lateral side 200a of the trailer 100b.

Unfortunately, the sensor 210a is not able to detect the upper edge 320a along all the longitudinal extension of the trailer 100b, in particular not the upper front (in the intended main moving direction 205 of the vehicle combination 110) of the trailer 100b. Based on the made sensor measurements of the sensor-visible section 310a, an extrapolation of the shape of the non-sensor-visible section 330a.

The trailer 100b may be modelled as a rectangular box; like a clothoid having a curvature which varies linearly; a second-degree polynomial; a third-degree polynomial, etc., based on the detected shape of the sensor-visible section 310a.

More generally, the upper edge 320 of the trailer 100b may be approximated or modelled by polynomial of degree n, where n is an arbitrary integer 1 < n < °°.

Having extrapolated the upper edge 320a of the trailer 100b, the highest point 120 of the extrapolated non-sensor-visible section 330a of the trailer 100b may be determined and a maximum height 130 over the road surface 105 of the determined highest point 120 of the vehicle combination 110 may be calculated.

Based on the estimated maximum height 130, an action may be performed, such as for example outputting information comprising the calculated maximum height 130 to a driver of the vehicle combination 110, when the tractor 100a is a manned vehicle.

As the tractor 100a turns in relation to the trailer 100b, e.g. in a sharp turn, the rearward looking sensor 210a, 210b of the tractor 100a may detect a larger part of the sensor-visible section 310a of the upper edge 320a than initially (with one of the rearward looking sensor 210a, 210b situated on the side of the vehicle combination 110 in which the turn is made. The rearward looking sensor 210a, 210b situated on the opposite side may detect a smaller part or even no part at all of the trailer 100b during the turn). The approximation of the trailer upper edge 320a may then be updated with the extended sensor-visible section 310a of the upper edge 320a, by selecting another model of the trailer 100b. In some cases, the rearward looking sensor 210a, 210b may detect the most forward situated end of the trailer upper edge 320a and conclude that the highest point 120 of the vehicle combination 110 is formed by this point.

A direct sensor observation by the rearward looking sensor 210a, 210b may replace any previously made approximation, leading to a more precise determination of the highest point 120, in some embodiments.

Figure 3B illustrates the vehicle combination 110 of Figure 3A, as regarded from the opposite lateral side. A rearward looking sensor 210b of the tractor 100a may detect a sensor- visible section 310b of the upper edge 320b of a second lateral side 200b of the trailer 100b.

Figure 3C is an overview of a scenario wherein a vehicle combination 110 formed by a tractor 100a and a trailer 100b, driving on a road segment 105 in a driving direction 205. The vehicle combination 110 may be the same or similar to the ones already discussed and illustrated in Figures 1A-1 F, Figures 2A-2B and/ or Figures 3A-3B. The vehicle combination 110 is passed by another vehicle 330 of arbitrary nature, having a sensor 340. The sensor 340 of the other vehicle 330 may obtain sensor measurements of at least some part of the section 310b of the upper edge 320b of one lateral side 200b of the trailer 100b, and also make sensor measurements of the length of the trailer 100b. This information may then be provided to the control arrangement of the tractor 100a via wireless communication such as e.g. V2V, etc. Also, or alternatively, the other vehicle sensor 340 may estimate maximum height 130 at the highest point 120 of the trailer 100b and provide this measurement value to the control arrangement of the tractor 100a.

In some embodiments, the vehicle combination 110 may drive in, i.e. be part of a platoon, The measurement points 310 of the upper edge 320 of the trailer 100b and/ or the measurement points 310 identifying the highest point 120 of the trailer 100b may be made by a sensor of another vehicle/ tractor of the same platoon. In case the vehicle combination 110 behind another vehicle in the platoon, a rearward looking sensor of the ahead vehicle may make and provide observations of the upper edge 320 of the trailer 100b and/ or the highest point 120 and/ or the maximum height 130 over the road 105 of the highest point 120 of the vehicle combination 110. In other cases, a behind vehicle having a forward-looking sensor may make observations of the upper edge 320 and/ or the highest point 120 of the trailer 100b.

Figure 4A illustrates an example of a vehicle interior of a tractor 100a forming a combined vehicle 110 together with a trailer 100b and depicts how the previously scenario in Figure 1A-1 F, Figure 2A-2B and/ or Figure 3A-3C may be perceived by the driver of the tractor 100a.

The tractor 100a comprises a control arrangement 410, which is communicatively connected to one or several rearward looking sensors 210a, 210b. The control arrangement 410 may receive information and measurements from the rearward looking sensor 210a, 210b and perform various calculations and estimations based on the received sensor measurements for estimating maximum height 130 of the vehicle combination 110.

The estimated maximum height 130 may then be used for route planning, i.e. selecting a road having a sufficient height on crossing bridges, road obstacles above the road, etc., to the destination. The allowed height of the ahead road 105 may be achieved from a map on a vehicle external database 405, or an on-board storage, for example.

The planned route and/ or destination of the vehicle combination 110 may be extracted from a navigator or positioning unit 420. The geographical position of the vehicle combination 110 may be determined by the positioning unit 420 of the tractor 100a. The positioning 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 420, (and thereby also of the tractor 100a I vehicle combination 110) may be made continuously with a certain predetermined or configurable time intervals according to various embodiments.

Having determined the geographical position of the positioning unit 420, it may be presented on a map, a screen or a display device where the position of the vehicle combination 110 may be marked, in some alternative embodiments.

It may thereby also be determined which road the vehicle combination 110 is driving on and in which driving direction 205. Height restrictions of the road may then be extracted from a database and possibly presented to the driver, if any, on an output device 440 in the cabin.

The calculated maximum vehicle height 130, height restrictions of current road 105 and/ or a planned route allowing for the maximum vehicle height 130 may be outputted on the output device 440 such as e.g. a display, a loudspeaker, a projector, a head-up display, a display integrated in the windshield of the tractor 100a, a display integrated in the dashboard of the tractor 100a, a tactile device, a portable device of the vehicle driver/ owner, a set of closeeyes displays (i.e. intelligent glasses) of the vehicle driver/ owner, etc.; or a combination thereof.

Figure 4B illustrates an example of a vehicle interior of a tractor 100a forming a combined vehicle 110 together with a trailer 100b, similar to the embodiment illustrated in Figure 4A.

In the illustrated embodiment, the combined vehicle 110 is approaching a height restriction 450 of the road 105. The height restriction 450 may be e.g. a bridge; a road intersection; a tunnel entrance; an entrance to a garage or other building; a structure for holding lamp posts, illumination, traffic signs, etc.

A road sign 460 situated at the road-side before the height restriction 450 may indicate the maximum clearance height of the height restriction 450, in the indicated example this height is 3,4 meters. The tractor 100a may in some embodiments comprise a (forward looking) sensor 470, communicatively connected to the control arrangement 410. The sensor 470 may comprise a camera or similar device, which may capture an image of the road sign 460 and provide information concerning the captured image to the control arrangement 410. The control arrangement 410 may work in conjunction with an image recognition software to detect and interpret the text/ letters/ digits on the road sign 460 in the correct context of an ahead height restriction 450.

The control arrangement 410 may thereby determine the height limitation of the height restriction 450, based on the information obtained from the sensor 470, as declared on the road sign 460, detected by the sensor 470.

Also, the control arrangement 410 may estimate maximum height 130 of the trailer 100b in the combined vehicle 110 according to the previously described solution. A comparison may then be performed between the estimated maximum height 130 and the height limitation of the height restriction 450 and in case the estimated maximum height 130 exceeds the height limitation, an alert may be outputted on the output device 440; and/ or a deceleration may be initiated in order to stop the combined vehicle 110 before arriving at the height restriction 450.

An alternative route to the destination may also be calculated and output to the driver, if any, allowing the combined vehicle 110 to reach the destination without passing the height restriction 450.

Figure 4C illustrates an example of a vehicle interior of a tractor 100a forming a combined vehicle 110 together with a trailer 100b, similar to the embodiments illustrated in Figure 4A and/ or Figure 4B.

In the illustrated embodiment, the forward-looking sensor 470 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. The sensor 470 may detect the height restriction 450 ahead of the tractor 100a/ combined vehicle 110 in the driving direction 205.

The control arrangement 410, which may be communicatively connected to the forwardlooking sensor 470, may then obtain sensor measurements of the height restriction 450, from the sensor 470. Based on the obtained sensor measurements, the control arrangement 410 may estimate the critical height of the height restriction 450 and compare it with the estimated height 130 of the highest point 120 of the trailer 100b. In case the estimated maximum height 130 exceeds the height restriction of the height restriction 450, an alert may be outputted on the output device 440; and/ or a deceleration may be initiated in order to stop the tractor 100a/ combined vehicle 110 before arriving at the height restriction 450.

Thereby, a severe accident may be avoided involving the combined vehicle 110.

An alternative route to the destination may also be calculated and output to the driver, if any, allowing the combined vehicle 110 to reach the destination without passing the height restriction 450.

The various features of the illustrated embodiments may with advantage be combined with each other in some embodiments for achieving certain benefits.

The control arrangement 410 may communicate with the sensors 210a, 210b, 340, 470, the navigator 420, the output device 440 and other electronic units via a wired or wireless communication bus of the tractor 100a, or via a wired or wireless connection. The communication bus may comprise e.g. a Controller Area Network (CAN) bus, a Media Oriented Systems Transport (MOST) bus, or similar. However, the communication may alternatively be made over a wireless connection.

Figure 5 illustrates an example of a method 500 according to an embodiment. The flow chart in Figure 5 shows the method 500 performed by a control arrangement 410 for a tractor 100a in a vehicle combination 110, which vehicle combination 110 comprises the tractor 100a and a trailer 100b.

The method 500 comprises performing 501 an action based on an estimated height 130 over a road surface 105 of a highest point 120 of an extrapolated section 330a, 330b of an upper edge 320a, 320b of the trailer 100b along a longitudinal extension of the trailer 100b. The section 330a, 330b of the upper edge 320a, 320b of the trailer 100b is extrapolated based on sensor detection of a shape/ geometry of a sensor-visible section 310a, 310b of the upper edge 320a, 320b of the trailer 100b and sensor data indicative of a position in height of at least one point of the sensor-visible section 310a, 310b.

The action to be performed 501 may be any appropriate action for avoiding inconvenience due to height of the trailer 100b in comparison with a height-limited passage 450 of the road ahead of the vehicle combination 110 and/ or along a planned route of the vehicle combination 110 towards a destination; such as for example output information concerning the estimated height 130, output an alert and/ or generate a command for an emergency brake. Also, an alternative route to the destination, avoiding the height-limited passage 450 may be calculated and suggested to the driver, if any.

The planned route to the destination may be extracted from a navigator 420 of the tractor 100a. Any height restriction of the planned route may then be extracted from a database 405 internal/ external to the tractor 100a.

The method 500 may in some embodiments comprise a number of sub-steps before being able to perform 501 the action. Thus, the control arrangement 410 may obtain sensor measurements of the upper edge 320a, 320b of the trailer 100b, i.e. sensor detection of the shape of the sensor-visible section 310a, 310b of the upper edge 320a, 320b of the trailer 100b and sensor data indicative of the position in height of the at least one point of the sensor-visible section 310a, 310b from a rearward looking sensor 210a, 210b of the tractor 100a, having a known position in height.

The method 500 may in some embodiments also comprise the sub-step of determining length of the trailer 100b. For example, information concerning the trailer length may be extracted from a memory device of the trailer 100b, from a memory device of the tractor 100a, and/ or from a vehicle external database 405.

Alternatively, in case the trailer length is not stored in any of the memory devices or the vehicle external database 405, the length of the trailer 100b may instead be estimated based on sensor measurement of the longitudinal rear end portion of the upper edge 320a, 320b of the trailer 100b and the longitudinal forward end portion of the upper edge 320a, 320b of the trailer 100b, by the rearward looking sensor 210a, 210b of the tractor 100a.

In case the rearward looking sensor 210a, 210b cannot detect the longitudinal forward end portion of the upper edge 320a, 320b of the trailer 100b, the length measurement may be made based on sensor measurement of the longitudinal rear end portion of the upper edge 320a, 320b of the trailer 100b and knowledge of the longitudinal rear end portion of the tractor 100a, assuming that the longitudinal forward end portion of the upper edge 320a, 320b of the trailer 100b will be situated behind the longitudinal rear end portion of the tractor 100a, at a predetermined distance.

In yet some embodiments, the length of the trailer 100b may be estimated by a vehicle external sensor 340, for example a sensor 340 on another vehicle or a sensor 340 situated at a trailer station or at a roadside for example. The measurement of the vehicle external sensor 340 may be communicated via wireless communication to the control arrangement 410. In another alternative embodiment, an image sensor 470 of the tractor 100a, or of a mobile device of the driver, if any, of the tractor 100a, may capture an image of the license plate on the trailer 100b. An image processing program may then determine nationality of the trailer 100b and make a search for the trailer length in a national vehicle register of the determine nationality.

The upper edge 320a, 320b of the trailer 100b comprises one sensor-visible section 310a, 310b and one non-sensor-visible section. Typically, the sensor-visible section 310a, 310b of the upper edge 320a, 320b comprises a rear part of the trailer 100b while the non-sensor- visible section of the upper edge 320a, 320b comprises a forward part of the trailer 100b, in the primary movement direction 205 of the combination vehicle 110.

The method 500 may additionally comprise the sub-step of extrapolating a section 330a, 330b of the upper edge 320a, 320b of the trailer 100b along a longitudinal extension, i.e. length of the trailer 100b, thereby recreating an estimated model of the non-sensor-visible section of the upper edge 320a, 320b.

By determining the shape of the sensor-visible section 310a, 310b of the upper edge 320a, 320b and assuming that the shape of the non-sensor-visible section 330a, 330b of the upper edge 320a, 320b will extend along the length of the trailer 100b in accordance with the shape of the sensor-visible section 310a, 310b, it becomes possible to extrapolate the non-sensor- visible section 330a, 330b of the upper edge 320a, 320b of the trailer 100b.

The method 500 may in addition comprise the sub-step of determining longitudinal and/ or lateral position of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b.

Also, the method 500 may comprise the additionally sub-step of determining height 130 over the road surface 105 of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b.

The determination of the height 130 over the road surface 105 of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b may be made with regard to a road inclination a at the height-limited passage 450, or at a place of the height restriction of the planned route to the destination.

In some embodiments, the tractor 100a may comprise at least one left side rearward looking sensor 210a and at least one right side rearward looking sensor 210b. The sub-step of extrapolation of the section 330a, 330b of the upper edge 320a, 320b of the trailer 100b along the longitudinal extension of the trailer 100b may then comprise extrapolation of a first section 330a of a first upper edge 320a of the trailer 100b along the longitudinal extension of a first lateral side 200a of the trailer 100b, based on a sensor measurement of a sensor- visible section 310a of the first upper edge 320a of the trailer 100b. The sub-step may also comprise extrapolation of a second section 330b of a second upper edge 320b of the trailer 100b along the longitudinal extension of a second lateral side 200b of the trailer 100b, based on a sensor measurement of a sensor-visible section 310b of the second upper edge 320b of the trailer 100b.

By extrapolating the respective extension of the upper edge 320a, 320b on each lateral side of the trailer 100b, and comparing them, it becomes possible to determine on which side the highest point 120 is situated. The height 130 of the highest point 120 may then be determined.

The height 130 of the highest point 120 may be estimated based on the extrapolated first section 330a of the first upper edge 320a and the second section 330a of the second upper edge 320b, respectively, of the trailer 100b.

Figure 6 illustrates an embodiment of a system 600 for a tractor 100a in a vehicle combination 110 comprising the tractor 100a and a trailer 100b.

The system 600 may perform the previously described method step 501 and/ or at least some of the previously described sub-steps according to the method 500 described above and illustrated in Figure 5.

For any of the embodiments described herein, the action performed based on the estimated height (130) over a road surface (105) of a highest point (120) of an extrapolated section (330a, 330b) of an upper edge (320a, 320b) of the trailer (100b) along a longitudinal extension of the trailer (100b), may be performed when said estimated height (130) is higher than e.g. the height of the at least one point of the sensor-visible section (310a, 310b). That is, in cases where the sensor-visible section of the trailer is actually higher than the estimated height of the non-sensor-visible section, a similar or different action may instead be performed based on the height of the sensor visible section, which in that case is the highest part of the trailer/vehicle combination.

The system 600 comprises at least one control arrangement 410 for a tractor 100a. The control arrangement 410 is communicatively connected to at least one rearward looking sensor 210a, 210b of the tractor 100a. The rearward looking sensor 210a, 210b may be configured to monitor at least a part of a side 200a, 200b of the trailer 100b.

The control arrangement 410 is configured to trigger performance of an action based on an estimated height 130 over a road surface 105 of a highest point 120 of an extrapolated section 330a, 330b of an upper edge 320a, 320b of the trailer 100b along a longitudinal extension of the trailer 100b. The section 330a, 330b of the upper edge 320a, 320b of the trailer 100b is extrapolated based on sensor detection of a shape of a sensor-visible section 310a, 310b of the upper edge 320a, 320b of the trailer 100b and sensor data indicative of a position in height of at least one point of the sensor-visible section 310a, 310b, obtained from the rearward looking sensor 210a, 210b of the tractor 100a.

The control arrangement 410 may in some embodiments be configured to trigger output of information on an output device 440, concerning the estimated height 130, an alert and/ or a recommended alternative route to a destination of the vehicle combination 110 when a height restriction of either a detected height-limited passage 450 in front of the vehicle combination 110, or a height restriction of a planned route to the destination, extracted from a navigator 420, is exceeded by the estimated height 130 over the road surface 105 of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b.

The information, alert and/ or recommended alternative route to the destination may be output on the output device 440, e.g. on a display, via a loudspeaker etc. An alert signal may possibly be output be a tactical device in the cabin of the tractor 100a when a driver is present, for example in combination with visual output on a display or via a projector and/ or a sound alert via a loudspeaker.

The control arrangement 410 may in some embodiments be configured to estimate the height 130 over the road surface 105 of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b, with regard to a road inclination a at the height-limited passage 450, or at a place of the height restriction of the planned route to the destination.

In some embodiments, the control arrangement 410 may be configured to extrapolate a first section 330a of a first upper edge 320a of the trailer 100b along the longitudinal extension of a first lateral side 200a of the trailer 100b. The extrapolation may be based on an obtained sensor measurement of a sensor-visible section 310a of the first upper edge 320a of the trailer 100b.

The control arrangement 410 may be configured to extrapolate a second section 330b of a second upper edge 320b of the trailer 100b along the longitudinal extension of a second lateral side 200b of the trailer 100b, based on an obtained sensor measurement of a sensor- visible section 310b of the second upper edge 320b of the trailer 100b.

The control arrangement 410 may also be configured to estimate the height 130 over the road surface 105 of the highest point 120 based on the extrapolated first section 330a of the first upper edge 320a and the second section 330a of the second upper edge 320b, respectively, of the trailer 100b.

In some embodiments, the control arrangement 410 may be additionally configured to obtain the sensor detection of the shape of the sensor-visible section 310a, 310b of the upper edge 320a, 320b of the trailer 100b and sensor data indicative of the position in height of the at least one point of the sensor-visible section 310a, 310b from a rearward looking sensor210a, 210b of the tractor 100a, having a known position in height in relation to the rest of the tractor 100a and the road 105.

The control arrangement 410 may be configured to estimate the height 130 of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b by determining longitudinal and/ or lateral position of the highest point 120 of the extrapolated section 330a, 330b of the upper edge 320a, 320b of the trailer 100b.

Also, the control arrangement 410 may be configured to extrapolate the section 330a, 330b of the upper edge 320a, 320b of the trailer 100b along the longitudinal extension of the trailer 100b, based on knowledge of a length of the trailer 100b.

In some embodiments, the control arrangement 410 may be configured to estimate the length of the trailer 100b based on a sensor measurement of the longitudinal rear end portion of the upper edge 320a, 320b of the trailer 100b obtained from the rearward looking sensor 210a, 210b of the tractor 100a, when the sensor-visible section 310a, 310b of the upper edge 320a, 320b of the trailer 100b, comprises the longitudinal rear end portion of the upper edge 320a, 320b of the trailer 100b.

In other embodiments the control arrangement 410 may be configured to extract the length of the trailer 100b from a memory device of the trailer 100b, from a memory device of the tractor 100a, or from a vehicle external database 405. In yet some embodiments, the control arrangement 410 may be configured to estimate the length of the trailer 100b based on sensor measurements obtained from a vehicle external sensor 340, concerning longitudinal extension of the trailer 100b.

The control arrangement 410 comprises a receiving circuit 610 configured for receiving a signal from the rearward looking sensor/s 210a, 210b of the tractor 100a, a forward-looking sensor 470 and/ or a vehicle external sensor 340.

Further, the control arrangement 410 comprises a processing circuitry 620 configured for performing at least a part of the method 500, according to some embodiments.

Such processing circuitry 620 may comprise one or more instances of a processing circuit, i.e. a Central Processing Unit (CPU) or other processing logic that may interpret and execute instructions.

Furthermore, the control arrangement 410 may comprise a memory 625 in some embodiments. The optional memory 625 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 625 may comprise integrated circuits comprising silicon- based transistors. The memory 625 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.

Further, the control arrangement 410 may comprise a signal transmitter 630 in some embodiments. The signal transmitter 630 may be configured for transmitting a signal to e.g. the output device 440, and/ or an alerting system or alerting device, for example.

The above-described method step 501 and/ or the at least some of the sub-steps may be implemented through the one or more processing circuitries 620 of the control arrangement 410, together with a computer program for performing at least some of the functions of the method step 501. The computer program comprises instructions which, when the program is executed by a computer, cause the computer to carry out the method step 501 of the method 500.

Further, some embodiments of the invention may comprise a tractor 100a, comprising the system 600. The computer program mentioned above may be provided for instance in the form of a data carrier carrying computer program code for performing at least some part of the method step 501 according to some embodiments when being loaded into the one or more processing circuitries 620 of the control arrangement 410. 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 may furthermore be provided as computer program code on a server and downloaded to the control arrangement 410 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 500; the control arrangement 410; the computer program; the system 600 and/ or the tractor 100a. 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.