GB2572144A

GB2572144A - A control module for a vehicle

Info

Publication number: GB2572144A
Application number: GB1804334.9A
Authority: GB
Inventors: John Greenwood Jeremy
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2018-03-19
Filing date: 2018-03-19
Publication date: 2019-09-25
Anticipated expiration: 2038-03-19
Also published as: GB201804334D0; GB2572144B

Abstract

A control module (12) for a vehicle (10), wherein the vehicle (10) comprises a tow vehicle (11) and a trailer (14), the control module (12) comprising: a first input (40) configured to receive a first input signal indicative of trailer accelerometer data being generated by a trailer accelerometer (16) associated with the trailer (14); a second input configured to receive a second input signal indicative of tow vehicle accelerometer data being generated by a tow vehicle accelerometer (15) associated with the tow vehicle (11); a processor (46) arranged to determine the length of the trailer (14) in dependence on the trailer accelerometer data and the tow vehicle accelerometer data; and an output (42) configured to output a signal indicative of the length of the trailer (14) as determined by the processor (46). Also provided is a method of determining the length of a trailer.

Description

TECHNICAL FIELD

The present disclosure relates to a control module for a vehicle and particularly, but not exclusively, to a control module for a vehicle comprising a tow vehicle and a trailer. Aspects of the invention relate to a control module, to a vehicle, to a trailer, to an articulated vehicle and to a method.

BACKGROUND

In modern vehicles it is desirable to provide users with systems that can assist them with their driving. These systems are often referred to as Advanced Driver Assistance Systems (ADAS) and come in many forms and variations, including systems such as towing systems, parking systems or lane guidance systems.

There is a desire to provide more ADAS features on vehicles to assist users complete tasks such as towing trailers such as caravans, boats or horse boxes. An example of such a driving assistance system that is currently available is Tow Assist® which provides assistance to a user of a vehicle whilst the vehicle is towing a trailer. However, ADAS features (such as Tow Assist®) often require users of the vehicle to manually input data to the ADAS features to ensure that such features are accurately calibrated such that they can provide accurate assistance to the user. This is particularly relevant when the features are designed to assist a user of the vehicle with manoeuvring or parking a vehicle with a trailer.

It is desirable to provide a solution that mitigates against vehicle users having to manually input data, such as the length of the trailer, into ADAS features that require data indicative of the vehicle or trailer in order to be calibrated correctly.

It is an aim of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a control module, a vehicle, a trailer, an articulated vehicle and a method.

According to an aspect of the present invention there is provided a control module for a vehicle, wherein the vehicle comprises a tow vehicle and a trailer, the control module comprising: a first input configured to receive a first input signal indicative of trailer accelerometer data being generated by a trailer accelerometer associated with the trailer; a second input configured to receive a second input signal indicative of tow vehicle accelerometer data being generated by a tow vehicle accelerometer associated with the tow vehicle; a processor arranged to determine the length of the trailer in dependence on the trailer accelerometer data and the tow vehicle accelerometer data; and an output configured to output a signal indicative of the length of the trailer as determined by the processor.

Advantageously, the control module enables the length of the trailer being towed by a tow vehicle to be calculated. This mitigates against a user of the vehicle from having to measure the length of the trailer being towed and manually inputting the length of the trailer into a human machine interface within the vehicle. The length of the trailer, as calculated by the control module, is approximately equal to the length from a hitch point, between the trailer and the tow vehicle, and the trailer accelerometer which is typically mounted on a rear surface of the trailer. The length of the trailer as calculated by the control module may be used by the vehicle to calibrate systems that require an indication of the length of the trailer for their function. In an embodiment the length of the trailer as calculated by the control module is approximately equal to double the distance between a rear axle of the tow vehicle and an axle of the trailer. The skilled person would appreciate that in embodiments where the trailer axle is not in the centre of the trailer that the length of the trailer would be approximately equal to a length other than double the distance from the rear axle of the tow vehicle to the axle of the trailer.

Furthermore, comparing accelerometer data from the tow vehicle accelerometer and accelerometer data from the trailer accelerometer provides the advantage of enabling the control module to monitor the displacement of the trailer relative to the tow vehicle which in turn may enable the control module to determine the length of the trailer.

In an embodiment, the trailer accelerometer data may be indicative of a trailer displacement relative to the tow vehicle. In another embodiment, the trailer displacement may be at least one of a lateral displacement or a vertical displacement of the trailer relative to the tow vehicle.

This is advantageous as the length of the trailer may be calculated by the control module when the trailer displaces relative to the tow vehicle, for example when the tow vehicle is travelling around a corner or when the position of the tow vehicle changes in a vertical displacement, for example when the tow vehicle travels over a speed bump or goes up/down a hill.

In another embodiment, the trailer accelerometer data and the vehicle accelerometer data vary with time, and the processor may be configured to determine the length of the trailer in dependence on a phase difference between the trailer accelerometer data and the vehicle accelerometer data. This is advantageous as it enables the control module to calculate the length of the trailer when the vehicle travels over a feature on the road surface that causes the vehicle to displace vertically, for example when travelling over a speed bump.

In an embodiment, the control module comprises a further input configured to receive a further input signal indicative of at least one of: the speed of the vehicle; the hitch angle of the trailer relative to the tow vehicle; or the turning radius of the vehicle; and wherein the processor is configured to determine the length of the trailer in dependence on at least the first input signal and the further input signal.

In another embodiment, the control module may be configured to calculate an outswing of the trailer relative to the path of the tow vehicle in dependence on the received trailer acceleration data. This is advantageous as the control module may calculate the length of the trailer as the tow vehicle travels around a corner by taking advantage of the fact that the trailer swings outward when the tow vehicle corners.

In an alternative embodiment, the output may be configured to provide the output signal to a vehicle system. In an embodiment the vehicle system may be one or more of an HMI; an ADAS feature; a towing system; a parking system; a blind spot system; or a lane guidance system. The vehicle system may be any system on the tow vehicle that requires the length of the trailer being towed by the tow vehicle to function and/ or be calibrated accurately. The aforementioned list of vehicle systems is by way of example and a person skilled in the art would appreciate that the length of the trailer may be output to vehicle systems not listed above.

In one embodiment the control module may be configured to store the length of the trailer, in association with a trailer identifier, in a memory module.

This is advantageous in situations where the control module has previously calculated the length of the trailer being towed by the tow vehicle. In these scenarios the control module may identify the trailer being towed by the tow vehicle, and thus the length of said trailer, based on the trailer identifier and length being stored in the memory module.

In another embodiment, the trailer accelerometer may be positionable on a rear surface of the trailer. In one embodiment, the trailer accelerometer forms part of an imaging device positionable on the trailer.

According to an aspect of the present invention there is provided a vehicle comprising the control module as referred to in any of the preceding paragraphs and at least one imaging device which is positioned on the trailer of the vehicle.

According to another aspect of the present invention there is provided a vehicle comprising the control module as described in any of the preceding paragraphs.

According to a further aspect of the present invention there is provided a trailer comprising the control module according to any of the preceding paragraphs.

According to another aspect of the present invention there is provided an articulated vehicle comprising the control module according to any of the preceding paragraphs.

According to another aspect of the present invention there is provided a method of determining the length of a trailer being towed by a tow vehicle, wherein the trailer comprises a trailer accelerometer configured to generate trailer acceleration data and the tow vehicle comprises a tow vehicle accelerometer configured to generate tow vehicle accelerometer data, the method comprising: receiving trailer accelerometer data generated by the trailer accelerometer; receiving tow vehicle accelerometer data generated by the tow vehicle accelerometer; determining the length of the trailer in dependence on the received trailer accelerometer data and the received tow vehicle accelerometer data; and outputting the length of the trailer.

In an embodiment, receiving trailer accelerometer data may comprise receiving trailer accelerometer data from a trailer accelerometer forming part of an imaging device. This is advantageous as it is becoming common practice to use removable imaging devices mounted to trailers. These imaging devices typically take the form of electronic video cameras, but may alternatively take the form of RADAR systems or LIDAR systems, any of which may further comprise accelerometers, and may be mounted on the rear surface of the trailer to assist the driver when driving, the method may take advantage of this and utilise accelerometer data from a trailer accelerometer mounted within an imaging device.

In another embodiment, receiving trailer accelerometer data may comprise receiving data indicative of a trailer displacement relative to the tow vehicle.

In an embodiment, the method may comprise receiving a signal indicative of at least one of: the speed of the vehicle; the hitch angle of the trailer relative to the tow vehicle; or the turning radius of the vehicle. In another embodiment the method may comprise determining the outswing of the trailer relative to the tow vehicle in dependence on receiving the trailer accelerometer data.

In another embodiment, the method may comprise storing the length of the trailer, in association with a trailer identifier, in a memory module.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a side view of an articulated vehicle comprising a tow vehicle and a trailer suitable for use with embodiments of the invention;

Figure 2 shows a plan view of the articulated vehicle of Figure 1;

Figure 3 shows a plan view of the articulated vehicle of Figure 1 travelling around a corner;

Figure 4 schematically shows a control module suitable for use with embodiments of the invention;

Figures 5a, 5b and 5c show a side view of the articulated vehicle of Figure 1 travelling over a feature on the road;

Figures 6a, 6b and 6c illustrate graphs showing the z-displacement of the tow vehicle and trailer, respectively, travelling over the feature of Figures 5a, 5b and 5c over a period of time; and

Figure 7 shows a flow chart of steps followed by the control module of Figure 4 when determining the length of the trailer of Figure 1.

DETAILED DESCRIPTION

In general terms embodiments of the invention relate to a control module 12 for an articulated vehicle 10. The vehicle 10 comprises a tow vehicle 11 and a trailer 14, and the control module 12 is configured to determine the length of the trailer 14 being towed by the tow vehicle 11. The trailer 14 includes a trailer accelerometer 16 mounted to a rear surface 17 of the trailer 14 such that when the vehicle 11 moves the trailer accelerometer 16 generates trailer accelerometer data. Similarly, the tow vehicle 11 has a tow vehicle accelerometer 15 configured to generate tow vehicle accelerometer data. The trailer accelerometer may form part of an imaging device, such as a removable reversing camera. The trailer accelerometer data and tow vehicle accelerometer data are input to the control module 12 and the control module 12 determines the length of the trailer 14 in dependence on the received trailer and tow vehicle accelerometer data. The length of the trailer 14 may be output to a vehicle system such as an advanced driver assistance system such Tow Assist® and/or a visual indication as to the relative position of the tow vehicle 11 and the trailer 14 may be presented on a display device to aid the driver manoeuvre the articulated vehicle 10

To place embodiments of the invention in a suitable context, reference will firstly be made to Figures 1 and 2 which illustrate schematically a tow vehicle 11 and a trailer 14 arrangement, known, and referred to herein, as an “articulated vehicle” 10, suitable for use with embodiments of the invention. The tow vehicle 11 may be, for example, a car, SUV, MPV, truck or tractor and the trailer 14 may be, for example, a caravan, horse box, boat trailer, semi-trailer or any other trailer suitable for being towed by a tow vehicle 11.

The trailer 14, attached to the tow vehicle 11 by means of an articulated hitch 19, is fitted with an accelerometer 16, herein referred to as a “trailer accelerometer”, configured to generate and transmit trailer accelerometer data to the control module 12. The trailer accelerometer data generated by the trailer accelerometer 16 is typically indicative of a lateral or vertical displacement of the trailer 14 relative to the tow vehicle 11. The trailer accelerometer 16 may be an independent device or may form part of an imaging device such as a removable reversing camera, a RADAR module or a LIDAR module associated with the trailer 16. The control module 12 may be located in the tow vehicle 11, the trailer 14, or the removable reversing camera comprising the imaging means.

The trailer 14 shown in Figure 1 has an axle arrangement 18 comprising an axle and two wheels located at opposing ends of the axle to support the trailer 14. In the example shown, the axle arrangement 18 is positioned substantially in the centre of the trailer 14 which is typical of many trailers towed by non-commercial tow vehicles such as caravans, boat trailers, or horseboxes. The position of the axle arrangement 18 is referred to as the “overhang ratio” which is defined as the distance between the articulated hitch 19 and the axle arrangement 18 divided by the distance between the rear surface of the trailer 17 and the axle arrangement 18. In the example shown, the overhang ratio is substantially equal to 1 as the axle arrangement 18 is located centrally.

The tow vehicle 11 comprises an accelerometer 15, herein referred to as a “vehicle accelerometer”, configured to generate vehicle accelerometer data and transmit said vehicle accelerometer data to the control module 12. The vehicle accelerometer data is typically indicative of a lateral and/ or vertical displacement of the tow vehicle 11.

The articulated vehicle 10 comprises a control module 12 which may form part of the tow vehicle 11 (as shown in Figure 1) or the trailer 14 (as shown in Figure 2). In the example shown in Figure 1 and 2, the tow vehicle 11 is fitted with a tow vehicle accelerometer 15. The tow vehicle accelerometer 15 is configured to provide an input signal to the control module 12 comprising tow vehicle accelerometer data indicative of the displacement of the tow vehicle 11.

Figure 1 also shows a set of Cartesian axes local to the vehicle 10 and comprising a longitudinal forward axis x, a lateral axis y and a vertical axis z. The axes are arranged so that forward vehicle travel in a forward gear is generally in the + x direction, and generally perpendicular to the y-axis. The + z direction is upwards, away from the ground over which the vehicle 10 is travelling. This labelling convention, local to the articulated vehicle 10, is used throughout.

Figure 3 illustrates schematically the articulated vehicle 10 travelling around a 90^e right hand corner. When the articulated vehicle 10 travels around a corner, the rear of the trailer 14 swings outward relative to the tow vehicle 11 when the articulated vehicle 10 initiates the turn before returning to follow the tow vehicle 11 once a constant radius of cornering is achieved. The tow vehicle 11 follows a tow vehicle path 32 which is defined as the outmost radius of curvature that the tow vehicle 11 follows when making the turn illustrated in Figure 3. The radius of the tow vehicle path 32 is determined by the control module 12 by monitoring, for example, the steering wheel angle of the tow vehicle 11 as the tow vehicle 11 travels around the corner or from the tow vehicle accelerometer data being generated by the tow vehicle accelerometer 15.

Figure 3 also illustrates a trailer path 34 which is defined as the innermost radius of curvature that the trailer 14 follows when making a turn. The region 36 bound by the vehicle path 32 and the trailer path 34 defines a region 36, known as the “swept region” that is swept by the articulated vehicle 10 as the articulated vehicle 10 turns the corner. The distance between the vehicle path 32 and the trailer path 34 is referred to as “off-tracking” or corner-cutting.

As mentioned previously, the rear of the trailer 14 swings outward away from the tow vehicle path 32 when the articulated vehicle 10 travels around a corner. The lateral displacement of the rear surface 17 of the trailer 14 relative to the tow vehicle path 32 when the articulated vehicle 10 is cornering is defined as the outswing 30. The magnitude of the outswing 30 is proportional to the length of the trailer 14. Thus, if the trailer outswing 30 is known then the length of the trailer 14 may be calculated. The length of the trailer 14 calculated by the control module 12 is approximately equal to the distance between the articulated hitch 19 and the trailer accelerometer 16 (positioned on the rear surface 17 of the trailer 14). The outswing 30 of the rear surface 17 of the trailer 14 may be captured by the trailer accelerometer data being generated and input to the control module 12 by the trailer accelerometer 16 associated with the rear surface 17 of the trailer 14. In the example shown in Figure 3, the trailer accelerometer data is indicative of a lateral displacement of the rear surface 17 of the trailer 16 relative to the tow vehicle 11.

The magnitude of the outswing 30 of the trailer 14 is proportional to the length of the trailer 14 and the radius of the turn or vehicle path 32. Thus, the length of the trailer 14 may be calculated by the control module 12 based on the magnitude of outswing of the trailer 14 as the articulated vehicle 10 travels around a corner. The control module 12 may use known parameters of the tow vehicle 11, such as the wheelbase of the tow vehicle 11 and the turn radius of the tow vehicle 11, when calculating the length of the trailer 14.

The tow vehicle 11 may be fitted with a video display device mounted within the vehicle cabin such that, in use, it is visible to the driver of the tow vehicle 11. The video display device may be configured as to display a plan view of the articulated vehicle 10 and any objects located within its surroundings in real time. Furthermore a predicted trajectory of both the tow vehicle 11 and the trailer 14 may be displayed on the video display device based on vehicle parameters such as vehicle speed and steering wheel angle. This is advantageous as the video display device may illustrate the predicted trajectory of the articulated vehicle 10, including the predicted outswing of the trailer 14, thereby providing the driver of the articulated vehicle 10 with guidance when manoeuvring so that the driver can take action to avoid unwanted outswing or offtracking of the trailer 14. Furthermore, the video display device may predict and display a preferred route around a corner to a driver where the preferred route is a route around a corner that minimises unwanted outswing or off-tracking thereby reducing the chance of the driver making a mistake when driving around a corner.

In an embodiment, the control module 12 assumes that the overhang ratio of the trailer 14 is substantially equal to 1 when calculating the length of the trailer 14. This is a fair assumption for the majority of trailers that are commonly towed by non-commercial tow vehicles, such as caravans or horse boxes. However, it is envisaged that a user of the vehicle 10 may override this assumption by manually inputting an overhang ratio appropriate for the trailer 14 being towed by the tow vehicle 11. For example, the user of the vehicle may manually input an appropriate value for the overhang ratio or the user may select the type of trailer 14 being towed from a predefined list. The predefined list has a list of trailer types that may be towed by the tow vehicle 11 with each option having an associated overhang ratio typical of said trailer type. The predefined list may include further trailer characteristics which are discussed in further detail below.

Figure 4 illustrates schematically an example of the control module 12, suitable for use with embodiments of the invention. The control module 12 comprises a first input 40 configured to receive an input signal indicative of trailer accelerometer data being generated by the trailer accelerometer 16 and a second input 41 configured to receive an input signal indicative of tow vehicle accelerometer data being generated by the tow vehicle accelerometer 15. Furthermore, the control module 12 comprises a memory module 44 configured to store data and a processor module 46 configured to determine the length of the trailer 14 in dependence on data received at the input 40 of the control module 12.

The control module 12 also comprises an output 42 configured to provide an output signal to a vehicle system indicative of the length of the trailer 14. The output signal may be output to another control module forming part of the articulated vehicle 10 or it may be output to a vehicle system such as one or more of the following: a humanmachine interface (HMI) within the vehicle cabin, a driver guidance system having a display to provide information to the driver such as an indication of the ideal driving line to avoid unwanted outswing or corner cutting of the trailer, an ADAS feature, a towing system to provide assistance to a user of the vehicle 11 when towing a trailer 14, a parking system to provide assistance to a user of the vehicle 10 when parking, a blind spot system to provide guidance to a user of the vehicle when an object is positioned within the vehicle’s blind spot, or a lane guidance system. The skilled person would appreciate that there may be other vehicle systems, such as other ADAS features, that may benefit from receiving data indicative of the length of the trailer 14 being towed by the tow vehicle 11.

Figures 5a to 5c show the articulated vehicle 10 travelling over a feature 50 such as a speed bump positioned on a road 52 upon which the articulated vehicle 10 is travelling. In this situation the tow vehicle 11 and trailer 14 are both subject to a vertical displacement substantially equivalent to the magnitude of the feature 50. The vertical displacement of the tow vehicle 11 and the trailer 14 is captured by the vehicle accelerometer data and the trailer accelerometer data respectively before being input to the control module 12. Figures 5a and 5b illustrate schematically the front axle 54 and rear axle 56 of the tow vehicle 11 negotiating the feature 50 on the road 52 respectively. Figure 5c shows the axle arrangement 18 of the trailer 14 negotiating the feature 50 on the road 52.

The acceleration data captured by the vehicle accelerometer 15 pertaining to the tow vehicle’s progress over the feature 50 may be usefully corroborated by capturing the transient change in vertical acceleration twice. The first change in vertical acceleration captured by the vehicle accelerometer 15 occurs when the front axle 54 of the tow vehicle 11 negotiates the feature 50 as shown in Figure 5a and the second change in vertical acceleration is captured by the vehicle accelerometer 15 when the second axle 56 negotiates the feature 50 as shown in Figure 5b. A third change in vertical displacement is captured by the trailer accelerometer 16 when the axle arrangement 18 of the trailer 14 travels over the feature 50 as shown in Figure 5c.

The acceleration data captured by the vehicle accelerometer 15 and the trailer accelerometer 16 is input to the control module 12. The time between each of the first, second and third vertical displacements is also captured and monitored by the control module 12. The speed of the tow vehicle 11 is known from vehicle speed sensors and the distance between the front and rear axle 54, 56 of the tow vehicle 11 is also known. The control module 12 compares the elapsed time between the front axle 54 negotiating the feature 50 and the rear axle 56 negotiating the feature 50 with the speed of the tow vehicle 11 thereby verifying both the fact that the first and second vertical displacements are a result of the same feature 50 and that the speed of the vehicle 10 is correct.

The control module 12 then compares the elapsed time between the second vertical displacement, resulting from the rear axle 56 negotiating the feature 50, and the third vertical displacement resulting from the axle arrangement 18 of the trailer 14 negotiating the feature 50 with the speed of the articulated vehicle 10. Thus, the distance between the rear axle 56 and the axle arrangement 18 of the trailer 14 may be calculated. In examples where the axle arrangement 18 of the trailer is positioned substantially in the centre of the trailer 14 (i.e. the overhang ratio equals 1) the distance between the rear axle 56 and the axle arrangement 18 may be doubled to give an approximation of the total length of the trailer 14. In examples where the axle arrangement 18 of the trailer 14 is not in the centre of the trailer 14 then the user may input the location of the axle arrangement, including the number of axles on the trailer 14 and the control module 12 may adjust the calculation of the total trailer length accordingly.

Turning now to Figure 6 which shows an example of the tow vehicle accelerometer data 61 and the trailer accelerometer data 63 input to the control module 12 when the articulated vehicle 10 travels along the road 52 is shown with respect to time in Figure 6a, Figure 6b and Figure 6c respectively. The tow vehicle accelerometer data 61 and the trailer accelerometer data 63 both vary with time as the articulated vehicle 10 travels along a given section of road 52. The transient vertical acceleration or Zdisturbance fluctuation 62 in the tow vehicle accelerometer data 61 shown in Figure 6a is a result of the front axle 54 of tow vehicle 11 travelling over the feature 50 on the road 52. In this example, the transient 62 is caused as the front axle 54 of the tow vehicle 11 negotiates the feature 50. Similarly, the transient vertical acceleration 64 illustrated in Figure 6b is a result of the rear axle 56 of the tow vehicle 11 negotiating the feature 50. A transient vertical acceleration, or Z-disturbance 66 shown in Figure 6c is a result of the trailer 14 travelling over the same feature 50 on the road 52 upon which the articulated vehicle 10 is travelling. The control module 12 can determine a phase difference 60, 67 or time, between each vertical acceleration fluctuation or disturbance 62, 64, 66 which, when compared with the speed that the articulated vehicle 10 is travelling at can be used to calculate the distance between the rear axle 56 of the tow vehicle 11 and the axle arrangement 18 of the trailer 14thereby allowing the length of the trailer 14 to be calculated by the control module 12.

The control module 12 may calculate the length of the trailer 14 when the articulated vehicle 10 is travelling around a corner, as shown in Figure 3, or when the articulated vehicle 10 travels over a feature 50 on the surface of the road 52 which causes the trailer 14 to displace vertically to the tow vehicle 11 as shown in Figures 6a, 6b and 6c. It is advantageous to calculate a value for the length of the trailer 14 when the vehicle 10 travels around a corner and when the vehicle 10 travels over a feature 50 on the road 52. The values calculated for the length of the trailer 14 in each of the aforementioned scenarios are stored in the memory module 44. The control module 12 may then determine the average trailer 14 length based on the trailer lengths stored in the memory module 44 to improve the accuracy of the calculated trailer 14 length. The control module 12 may calculate and store multiple values for the length of the trailer 14 so that an average trailer length may be calculated. The more values the control module 12 calculates the more accurate the estimate of the trailer length is likely to be.

The control module 12 is configured to calculate the length of the trailer 14 at the start of a drive cycle such that the length of the trailer 14 may be input into vehicle systems that require the length of the trailer to calibrate. When the control module 12 calculates the length of the trailer 14 the length of the trailer 14 is stored in the memory module 44 of the control module 12. Each trailer 14 being towed by the tow vehicle 11 has an associated unique identifier, such that the length of the trailer 14 and the associated unique identifier may be stored together in the memory module 44. This is advantageous as once the control module 12 calculates the length of the trailer 14 the data is stored in the memory module 44 and may be retrieved by the control module 12 in subsequent drive cycles thereby mitigating against the need to calculate the length of the trailer 14 being towed by the tow vehicle 11 at the start of every drive cycle prior to calibrating vehicle systems or ADAS features.

The control module 12 may be configured to continue to calculate the length of the trailer 14 periodically throughout the duration of a drive cycle to improve the accuracy of the length of the trailer 14 as determined by the control module 12. For example, the control module 12 may calculate the length of the trailer 14 at predetermined discrete time intervals and store the results in the memory module 44 of the control module 12. The control module 12 may then calculate an average trailer length based on the calculated trailer lengths which the control module 12 may output to a vehicle system. The average trailer length, and associated trailer identifier, can then be stored in the memory module 44 within the control module 12.

As previously mentioned, the control module 12 may include a predefined list of trailers, including trailer characteristics associated with each trailer type. The predefined list is typically displayed to the user of the vehicle by way of a display or HMI located within the vehicle cabin. For example, if the user selects “horsebox” from the predefined list then the control module 12 selects the trailer characteristics that are typical for a “horsebox”. The trailer characteristics may include an overhang ratio typically associated with each trailer type. The overhang ratio alters the magnitude of outswing 30 experienced by a trailer 14 when cornering and thus it is advantageous to accurately estimate the overhang ratio for the trailer 14 prior to calculating the length of the trailer 14 via the outswing 30. As mentioned previously, the overhang ratio for many non-commercial caravans and horseboxes is 1, however, some large trailers, such as fifth wheel campers and some commercial trailers or semi-trailers the overhang ratio may vary greatly.

The user of the articulated vehicle 10 may manually input further trailer characteristics to the control module 12 such as number of axles on the trailer 14 or length of the articulated hitch 19. This is advantageous as characteristics of trailers may vary thus providing the user of the vehicle with a means of inputting trailer characteristics may improve the accuracy of the value of the length of the trailer calculated by the control module 12.

Furthermore, the trailer characteristics may include data indicative of the door type associated with each trailer type. This is particularly advantageous when the length of trailer 14 is being input to a parking assistance system. The length of the door on the rear surface 17 of the trailer 14 may be added to the calculated length of the trailer 14 to give an approximation of the length of parking space required for the entire articulated vehicle 10. For example, if the user selects the trailer type as “horsebox”, where the door is typically located on the rear surface 17 of the trailer 14 then the articulated vehicle 10 would require a larger parking space than if the user had selected an alternative trailer type, such as “caravan”, where the door of the vehicle is located on a side surface of the trailer 14.

Figure 7 shows the steps followed by the control module 12 when determining the length of the trailer 14. The first step 100 the control module 12 receives an input signal indicative of trailer accelerometer data being generated by the trailer accelerometer 16. The trailer accelerometer data may be indicative of a lateral and/or 5 vertical displacement of the trailer 14 relative to the tow vehicle 11.

In the next step 200, the control module 12 receives an input signal indicative of tow vehicle accelerometer data being generated by the tow vehicle accelerometer 15. In the next step 300 the control module 14 determines the length of the trailer 14 in 10 dependence on the received trailer accelerometer data. In the final step 400, the control module 12 outputs the length of the trailer to a vehicle system.

Many modifications may be made to the above examples without departing from the scope of the present invention as defined in the accompanying claims.

Claims

1. A control module for a vehicle, wherein the vehicle comprises a tow vehicle and a trailer, the control module comprising:

a first input configured to receive a first input signal indicative of trailer accelerometer data being generated by a trailer accelerometer associated with the trailer;

a second input configured to receive a second input signal indicative of tow vehicle accelerometer data being generated by a tow vehicle accelerometer associated with the tow vehicle;

a processor arranged to determine the length of the trailer in dependence on the trailer accelerometer data and the tow vehicle accelerometer data; and an output configured to output a signal indicative of the length of the trailer as determined by the processor.

2. A control module as claimed in claim 1, wherein the trailer accelerometer data is indicative of a trailer displacement relative to the tow vehicle.

3. A control module as claimed in claim 2, wherein the trailer displacement is at least one of a lateral displacement or a vertical displacement of the trailer relative to the tow vehicle.

4. A control module as claimed in any preceding claim, wherein the trailer accelerometer data and the vehicle accelerometer data vary with time, and wherein the processor is configured to determine the length of the trailer in dependence on a phase difference between the trailer accelerometer data and the vehicle accelerometer data.

5. A control module as claimed in any preceding claim, wherein the control module comprises a further input configured to receive a further input signal indicative of at least one of: the speed of the vehicle;

the hitch angle of the trailer relative to the tow vehicle; or the turning radius of the vehicle; and wherein the processor is configured to determine the length of the trailer in dependence on at least the first input signal and the further input signal.

6. A control module as claimed in any preceding claim, wherein the control module is configured to calculate an outswing of the trailer relative to the path of the tow vehicle in dependence on the received trailer acceleration data.

7. A control module as claimed in any preceding claim, wherein the output is configured to provide the output signal to a vehicle system.

8. A control module as claimed in claim 7, wherein the vehicle system is one or more of an HMI; an ADAS feature; a towing system; a parking system; a blind spot system; or a lane guidance system.

9. A control module as claimed in any preceding claim, wherein the control module is configured to store the length of the trailer, in association with a trailer identifier, in a memory module.

10. A control module as claimed in any preceding claim, wherein the trailer accelerometer is positionable on a rear surface of the trailer.

11. A control module as claimed in any preceding claim, wherein the trailer accelerometer forms part of an imaging device positionable on the trailer.

12. A vehicle comprising the control module as claimed in claim 11, and including the at least one imaging device.

13. A vehicle comprising the control module of any of claims 1 to 10.

14. A trailer comprising the control module of any of claims 1 to 11.

15. An articulated vehicle comprising the control module of any of claims 1 to 11.

16. A method of determining the length of a trailer being towed by a tow vehicle, wherein the trailer comprises a trailer accelerometer configured to generate trailer acceleration data and the tow vehicle comprises a tow vehicle accelerometer configured to generate tow vehicle accelerometer data, the method comprising:

receiving trailer accelerometer data generated by the trailer accelerometer; receiving tow vehicle accelerometer data generated by the tow vehicle accelerometer;

determining the length of the trailer in dependence on the received trailer accelerometer data and the received tow vehicle accelerometer data; and outputting the length of the trailer.

17. A method as claimed in claim 16, wherein receiving trailer accelerometer data comprises receiving trailer accelerometer data from a trailer accelerometer forming part of an imaging device.

18. A method as claimed in claim 16 or 17, wherein receiving trailer accelerometer data comprises receiving data indicative of a trailer displacement relative to the tow vehicle.

19. A method as claimed in any of claims 16 to 18, wherein the method comprises receiving a signal indicative of at least one of:

the speed of the vehicle;

the hitch angle of the trailer relative to the tow vehicle; or the turning radius of the vehicle.

20. A method as claimed in any of claims 16 to 19, wherein the method comprises determining the outswing of the trailer relative to the tow vehicle in dependence on receiving the trailer accelerometer data.

21. A method as claimed in any of claims 16 to 20, wherein the method comprises storing the length of the trailer, in association with a trailer identifier, in a memory module.