GB2528974A

GB2528974A - Towing stability

Info

Publication number: GB2528974A
Application number: GB1414070.1A
Authority: GB
Inventors: Jeremy Greenwood
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2014-08-08
Filing date: 2014-08-08
Publication date: 2016-02-10
Anticipated expiration: 2034-08-08
Also published as: GB2543388A; GB201614204D0; GB2528974B; GB201414070D0; GB2543388B

Abstract

A system for assessing the towing stability of a trailer 190 and a towing vehicle 100 comprises data processing apparatus such as a first electronic control unit (ECU) 110A. The first ECU 110A is configured to receive data from a second ECU 120A in the vehicle trunk. The data is typically derived from a strain gauge 101SG and corresponds to a measured nose weight of the trailer 190. The first ECU 110A ascertains towing stability by determining if the nose weight of a trailer complies with at least one nose weight condition. The first ECU 110A also comprises means for producing an output indicative of the towing stability of the trailer and towing vehicle. The invention improves on a prior art method which involved manual assessment and may have been subject to operator error.

Description

TOWING STABILITY

TECHNICAL FIELD

The present disclosure relates to towing stability. In particular, but not exclusively, embodiments of the present invention relate to a system and a method for assessing the stability of a towing vehicle and trailer, and to a vehicle comprising such a system. Aspects of the invention relate to an apparatus, to a system, to a method and to a vehicle.

BACKGROUND

As shown in FIG. 1 and FIG. 2, a trailer T is typically hitched to a towing vehicle V by means of a tow bar 1 and a tow ball lb attached to the tow bar 1. The trailer I is attached to the tow ball lb by means of a coupling head 2 that is provided at the front of the trailer 1.

When the trailer I is hitched to the towing vehicle V, the trailer T subjects the tow ball lb to a vertical load. The vertical load is commony referred to as the nose weight (NW) of the trailer T. The nose weight of the trailer T may also be referred to as the nose load, tongue load or static vertical load.

Trailers are typically assigned a maximum permissible nose weight value NW_trailer_max by the manufacturer which indicates the maximum value of nose weight to wftch the trailer may safely be subject in order not to cause damage to the trailer.

Similarly, tow bar manufacturers also typically assign a maximum permissible nose weight value NW_tow_bar_max to their tow bars, indicating the maximum value of nose weight to which the tow bar 1 may safely be subject in order not to cause damage to the tow bar 1.

Vehicles V are also typically assigned a maximum permissible nose weight limit value NW_vehicle_max by the manufacturer, indicating the maximum value of trailer noseweight (sometimes including the weight of tow bar and tow ball) with which the vehicle may safely operate. The nose weight limit may also be referred to as an S value.

If the nose weight acting on the tow ball lb has a value that is too high, NW_high, as shown in FIG. 3, then the towing vehicle V may be tilted backwardly, lowering the vehicle rear suspension and raising the front suspension. As a result, the front tyres of the vehicle V may have limited traction, the steering may be less effective, the braking capacity may be reduced and the headlights may be raised above the legal limit. Equally, if the nose weight acting on the tow ball 1 has a value that is too low, NW_low, as shown in FIG. 4, then the traUer T may tilt backwardly, raising the towing vehicle rear suspension. The trailer I may also act as a pendulum, causing it to become unstable and "snake" along the road.

This can be dangerous and lead to accidents.

It has been found empirically that the ratio of noseweight NW to gross trailer weight, referred to as the noseweight ratio', is a useful indicator of the stability of a vehicle/trailer combination. Optimum stability has found to be achieved when the noseweight ratio is in the range from 5% to 7%.

Accordingly, to help avoid towing stability problems, it is generally recommended that the nose weight ratio of a trailer T should be measured prior to towing to find out if it falls within the range 5 -7%. It is also necessary to ensure that the nose weight does not exceed the maximum value for which the trailer, tow bar or vehicle is rated.

The nose weight of a trailer T is conventionally measured by using a weight measuring gauge onto which the coupling head 2 of the trailer is lowered, with the trailer T decoupled from the vehicle V. The measured nose weight is then manually compared with the maximum allowable nose weight (being the smaller of the maximum permissible nose weights of the trailer, tow bar and vehicle). The nose weight ratio is also calculated, in order to ensure that it falls within the recommended range of 5-7%. If the nose weight meets the limits imposed by the trailer, tow bar and vehicle but does not fall within the recommended range of noseweight ratios, a user typically attempts to redistribute a load on the trailer so that the nose weight ratio falls within the recommended range.

This present applicant has recognised that the above described assessment process is not an easy or reliable method for evaluating towing stability. The process is not ideal because it requires the operator to be in-situ to manually read the nose weight measured by nose weight measurement apparatus, it is dependent on the information relating to the nose weight limits being readily available to the operator and it is governed by the operator knowing and understanding how to manually assess whether the measured nose weight complies with the towing stability requirements. The process is highly vulnerable to operator error in determining trailer nose weight at least, and misinterpretation of information.

Embodiments of the present invention seek to address or overcome at least some of the problems associated with the prior art. Embodiments of the present invention seek to provide an mproved and alternative system and method for assessing the towing stability of a trailer and towing vehicle.

SUMMARY OF THF INVFNTION

In an aspect of the invention for which protection is sought, there is provided a system for assessing the towing stability of a trailer and a towing vehicle comprising a first data processing apparatus, wherein the first data processing apparatus comprises: input means configured to receive data from a second data processing apparatus corresponding to a measured nose weight of a trailer; processing means configured to ascertain the towing stability by determining if the measured nose weight of a trailer complies with the at least one nose weight condition; and output means configured to produce an output indicative of the towing stability of a trailer and towing vehicle.

In an aspect of the invention for which protection is sought, there is provided a system for assessing the towing stability of a trailer and a towing vehicle comprising a first data processor, wherein the first data processor comprises: input means configured to receive data corresponding to a measured nose weight of a trailer; processing means configured to determine if the measured nose weight of the trailer complies with at least one nose weight condition; and output means configured to produce an output indicative of the towing stability of the trailer and towing vehicle in dependence on said determination.

Optionally, the first data processor is configured to receive the data corresponding to the measured rose weight of a trailer from a second data processor. Alternatively the first data processor may be configured to receive the data corresponding to the measured nose weight of a trailer substantially directly from sensor means such as a strain gauge or load cell. Other arrangements are also useful.

Embodiments of the present invention have the advantage that the determination as to whether the trailer and vehicle meet certain requirements for towing stability may be performed automatically by the system. The system may receive information relating to a

S

measured nose weight of the trailer without a user to being required to determine the information manually, and input the information to the system.

Optionally, the first data processor comprises input means configured to receive data relating to the at least one nose weight condition.

The system may be configured to assess the towing stability of the trailer and towing vehicle by determining whether the measured nose weight meets each of a plurality of different nose weight conditions. Two or more of the nose weight conditions may be in the form of upper limits to the allowable value of nose weight.

The first data processor may be configured to ascertain the towing stability by determining if the measured nose weight of a trailer is less than, optionally less than or substantially equal to, the smaller of the two or more nose weight limits.

Optionally, the first data processor comprises input means configured to receive data relating to a plurality of nose weight conditions, the plurality of noseweight conditions including a plurality of nose weight limits.

Optionally, the data relating to at least one nose weight condition may include data relating to a ratio of nose weight to gross trailer weight. Alternatively, the data relating to at least one nose weight condition may include data relating to a ratio of nose weight to maximum allowable gross trailer weight. At least one said at least one condition may be that the nose weight ratio is substantially equal to a predetermined value, or that the ratio falls within a predetermined range of nose weight ratio values.

By gross trailer weight is meant an actual weight of the trailer including any load carried by the trailer. By maximum allowable gross weight is meant the maximum allowable weight including any load carried by the trailer. The maximum allowable gross weight is a predetermined weight value, typically determined by a manufacturer of the traHer. It is to be understood that an operator of the trailer may set a maximum allowable gross weight that is less than that set by the manufacturer. Operators typically do not set maximum allowable gross weights that are greater than that set by the manufacturer, for safety and regulatory reasons.

The nose weight ratio may be expressed as a proportion, for example as a percentage of the gross weight of the trailer. For example, for a specific trailer, towing vehicle and tow bar combination, the nose weight ratio for optimum towing stability may be a nose weight of approximately 7% of the gross trailer weight.

Optionally, the first data processor may be configured to ascertain towing stability by determining if the measured nose weight of the trailer is an allowable proportion of the gross weight of the trailer.

The one or more nose weight conditions for acceptable towing stability may include the condition that the nose weight ratio falls within a certain percentage range of ratios. For example, sufficient towing stability may be achievable across a nose weight range of approximately 5% -15% of the gross trailer weight, or preferably across a nose weight range of approximately 5% -7% of the gross trailer weight. The allowable proportion may therefore be a value falling within an allowable range of proportions.

Accordingly, in an embodiment, there may be provided a system for assessing towing stability comprising a first data processing apparatus, wherein the first data processing apparatus comprises: input means configured to receive from a second data processing apparatus corresponding data corresponding to a measured nose weight of a trailer; input means configured to receive data relating to a gross weight of the trailer; processing means configured to ascertain towing stability by determining if the measured nose weight of the trailer is an allowable proportion of the gross weight of the trailer; and output means configured to produce an output indicative of the towing stability.

The processing means may be configured to ascertain the towing stability by determining if the measured nose weight of the trailer is an allowable proportion by determining if the nose weight of the trailer falls within a predetermined range of allowable proportions of the gross weight of the trailer.

The gross weight of the trailer may be a measured gross weight of the trailer including any load to be transported by the trailer. If a measured gross weight is not available, then the gross weight of the trailer may be a maximum permissible gross weight of the trailer. The maximum permissible gross weight may be a value declared by a manufacturer.

As described above, trailers, towing vehicles and tow bars may each have a specific nose weight limit associated therewith. To achieve an acceptable towing stability during towing, the measured nose weight of a trailer should preferably not exceed the maximum permissible nose weight limit of the trailer, the maximum permissible nose weight of the towing vehicle and/or the maximum permissible nose weight of the tow bar.

Accordingly, in an embodiment there is provided a system for assessing towing stability comprising a first data processing apparatus, wherein the first data processing apparatus comprises: input means configured to receive data from a second data processing apparatus corresponding to a measured nose weight of a trailer; input means configured to receive data relating to a maximum permissible nose weight limit of a tow bar, a maximum permissible nose weight limit of a trailer and/or a maximum permissible nose weight limit of a towing vehicle; processing means configured to ascertain towing stability by determining if the measured nose weight complies with the maximum permissible nose weight limit of the tow bar, the maximum permissible nose weight limit of the trailer and/or the maximum permissible nose weight limit of the towing vehicle; and output means configured to produce an output indicative of towing stability.

A plurality of nose weight limits may be received. Advantageously, to allow the system to take account of the different towing stability requirements of the trailer, towing vehicle and/or tow bar, the processing means may be configured to ascertain the towing ability by determining if the measured nose weight of the trailer complies with at least the smaller of the maximum permissible nose weight limit of the tow bar, trailer and/or the towing vehicle.

The output means may be configured to indicate the trailer and towing vehicle will have at least sufficent towing stability during towing if the processing means finds that the measured nose weight of the trailer conforms with each of the nose weight conditions. In respect of a situation where a plurality of nose weight limits are provided, the nose weight limits may be met if the measured nose weight is less than or equal to the smaller of the nose weight limits.

The output means may be configured to indicate that the trailer and towing vehicle will be unstable during towing if the processing means finds that measured nose weight of the trailer breaches one or more nose weight limits. The output means may be configured to indicate that the trailer is safe/not safe to tow due to the measured nose weight of the trailer. Accordingly, an operator may be prompted by such an output to reconfigure the trailer and/or any load so as to adjust the measured nose weight of the trailer within acceptable towing stability limits.

The output means may be configured to provide a visible signature and/or an audible signature to an operator indicative of towing stability.

The output means may be configured to provide an output via output means of the vehicle such as a dashboard display, by means of a mobile communications device carried by an operator, or by any other suitable means.

The output means may be arranged to provide a traffic light visual guide. Optionally, a green coloured signature indicates the towing stability of the trailer and towing vehicle will be acceptable when towing and a red coloured signature indicates that the towing stability of the trailer and towing vehicle is unacceptable. The output means may comprise an amber coloured signature which is activated to indicate that the towing stability is borderline and may be improved to become acceptable. The output means may comprise a graphical display such as a bar chart. The peak bar or bars of the bar chart may relate to the optimum towing stability available. The output means may be configured to provide a numerical signature indicative of towing stability. The output means may be configured to issue one or more audible indications such as spoken indications.

The input means for receiving data relating to the measured nose weight of the trailer is configured to receive the data from a second data processing apparatus so as to allow the system to automatically assess trailer stability without requiring a user to manually input the data. The input means may be configured to automatically receive the data from a trailer nose weight measuring device via a wired or a wireless data communications lnk.

The input means for receiving data relating to at least one nose weight imit may be configured to receive data via a wired or a wireless data communications link. Depending on the type of nose weight limit, the input means may be configured to receive data relating to at least one nose weight limit from data processing apparatus associated with the tow bar, towing vehicle and/or the trailer.

To allow for manual intervention, the input means for receiving data may be configured to allow for data relating to the measured nose weight and/or for data relating tc at least one nose weight limit to be manually input and stored in a database. As a result, the manufacturer, dealer, fitter or operator of the trailer/towing vehicle/tow bar may be able to preload relevant data when configuring the system, trailer, tow bar and/or the towing vehicle or be able to upload data should there be a systems failure.

The input means may be configured to allow for the data relating to the measured nose weight of the trailer and/or for the data relatng to the at least one nose weight limit to be automatically received in real time, optionally automatically at repeated intervals, so as to allow for a real time assessment of the towing stability, optionally on request by an operator. The system may be configured to assess towing stability prior to towing. The system may be configured to assess the stability of the trailer and towing vehicle during the towing process. The system may be configured to assess the stability of the trailer and towing vehicle only at appropriate predetermined moments whilst towing. For example, the system may assess stability by measuring nose weight only when the vehicle is stationary.

Optionally, the system may assess stability by measuring nose weight only when the vehicle is stationary and a gradient of a drivng surface does not exceed a predetermined value.

Additionally or alternatively, the input means may be configured to allow for the data relating to the measured nose weight of the trailer and/or the data relating to at least one nose weight limit to be pre-recorded and stored in a database. As a result, the data can be retrieved from the database by the processing means as and when an operator requires a towing stability assessment.

One or more means of the first data processing apparatus may be comprised by an electronic towing stability control unit for a vehicle. One or more means of the first data processing apparatus may be additionally or alternatively comprised by a portable communications device carrying computer readable code.

The system may comprise measuring means for measuring the nose weight of the trailer.

The system may additionally comprise the second data processing apparatus and transfer means for transmitting data relating to the measured nose weight via a wired or wireless communications link from the second data processing apparatus to the corresponding data input means of the first data processing apparatus. The second data processing apparatus

S

may form part of a nose weight measurement system comprising the means for measuring the nose weight of the trailer.

Depending on the type of nose weight limit used by the system to assess towing stability, the system may comprise measuring means for measuring the gross weight of the trailer and any load. The system may additionally comprise transfer means for transmitting data relating to the measured gross weight of the trailer and any load via a wired or wireless communications link to the corresponding data input means of the first data processing apparatus.

The means for measuring the nose weight of the trailer, means for measuring the gross weight of the trailer and any load and/or any associated data transfer means may be comprised by data processing apparatus of the system such as the second data processing apparatus.

One or more means of the second data processing apparatus may, in turn, be comprised by an electronic control unit for a trailer.

In a further aspect of the invention for which protection is sought there is provided a method of assessing the towing stability of a trailer and a towing vehicle comprising: receiving data corresponding to a measured nose weight of a trailer; determining if the measured nose weight of a trailer complies with at least one nose weight condition; and providing an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.

A further aspect of the invention for which protection is sought relates to a method for assessing the towing stability of a trailer and towing vehicle, the method comprising: (a) providing a system according to an aspect of the invention; (b) receiving data relating to a measured nose weight of the trailer; (c) receiving data relating to at least one nose weight limit for acceptable towing stability; (d) determining the towing stability of the trailer and towing vehicle by comparing the measured nose weight with respect to one or more of the nose weight limits, whereby the towing stability is deemed to be acceptable if the measured nose weight complies with one or more of the nose weight limits and the towing stability is deemed to be unacceptable if the measured nose weight does not comply with one or more of the nose weight limits; (e) indicating the towing stability of the trailer and towing vehicle.

Optionally, step (c) comprises receiving a plurality of nose weight limits; and step (d) comprises determining the lowest nose weight limit from the multiple nose weight limits and comparing the measured nose weight with respect to the lowest nose weight limit, whereby the towing stability is deemed to be acceptable if the measured nose weight complies with the lowest nose weight limit and the towing stability is deemed to be unacceptable if the measured nose weight does not comply with the lowest nose weight limit.

In an aspect of the invention for which protection is sought there is provided a vehicle comprising at least one means of the first data processor of the system for assessing towing stability.

In an aspect of the invention for which protection is sought there is provided there is provided an electronic control unit for a vehicle comprising at least one means of the first data processor of the system for assessing towing stability.

An aspect of the invention relates to a mobile communication device comprising at least one means of the first data processor of the system for assessing towing stability. The mobile communication device may be a smart telephone or laptop computer. The mobile communications device may have a graphic user interface (GUI) displaying an icon corresponding to a software application (otherwise referred to as an "app") for implementing at least the output means of the first data processing apparatus. The app allows the system to be retro-fitted simply and quickly without having to reconfigure the towing vehicle.

An aspect of the invention relates to a carrier medium carrying a computer readable code for controlling a mobile communications device to implement at least one means of the first data processor of the system for assessing towing stability or to carry out the method for assessing towing stability.

An aspect of the invention relates to a trailer comprising the at least one means of the second data processor of the system for assessing towing stability.

In an aspect of the invention for which protection is sought there is provided an apparatus for assessing a vehicle: an input configured to receive data corresponding to a measured nose weight of a trailer coupled to said vehicle; a processor configured to determine if the measured nose weight of the trailer complies with at least one nose weight condition; and output means configured to produce an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.

In another aspect of the invention for which protection is sought there is provided a vehicle having an apparatus as described in the foregoing aspect.

Some embodiments of the present invention provide a system for assessing the towing stability of a trailer and a towing vehicle. The system may comprise a first electronic control unit (ECU) that has an electrical input configured to receive data corresponding to a measured nose weight of a trailer. In some embodiments the data may be obtained from a nose weight measuring device that may be associated with a tow ball or tow hook of a towing vehicle. In some alternative embodiments the data may be obtained from a nose weight measuring device associated with a trailer such as a device mounted to an A' frame of the trailer. A second ECU associated and optionally collocated with the noseweight measuring device may transmit the data to the first ECU. The first ECU may have a processor configured to ascertain the towing stability by determining if the measured nose weight of a trailer complies with at least one nose weight condition.

Calculation of the noseweight condition may require data in respect of a weight of a trailer such as an actual gross weight of a trailer, or a manufacturer's maximum permitted gross weight of the trailer. This information may be provided to the first ECU by a user, for example by an input such as a keyboard or touchscreen. Alternatively the information may be obtained from an ECU of the trailer, which may optionally be the second ECU if that is installed in or on the trailer. The first ECU may also have an electrical output configured to produce an output indicative of the towing stability of a trailer and towing vehicle. The output may be provided via a display console installed in the vehicle. In some embodiments the output may be provided by a smartphone. The first ECU may be comprised by a smartphone or other portable device.

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 figures in which: FIGURE 1 shows a known trailer coupling head, tow bar and tow ball; FIGURE 2 illustrates how a nose weight of a trailer acts downwardly on a tow bar when the trailer is hitched to a towing vehicle via the tow bar; FIGURE 3 illustrates how the towing stability and safety of the trailer and towing vehicle are compromised when the nose weight acting on the tow bar is too high; FIGURE 4 illustrates how the towing stability and safety of the trailer and towing vehicle are compromised when the nose weight acting on the tow bar is too low; FIGURE 5 illustrates a vehicle having a system according to an embodiment of the present invention installed therein; FIGURE 6 illustrates a computing apparatus according to an embodiment of the present invention installed in the vehicle of FIG. 5; and FIGURE 7 illustrates a vehicle having a system according to a further embodiment of the present invention installed therein.

DETAILED DESCRIPTION

Embodiments of the present invention are directed to providing an automatic system and method for assessing the towing stability of a trailer and towing vehicle, and to a vehicle comprising such an automatic system.

FIG. 5 illustrates a towing vehicle 100 according to an embodiment of the present invention coupled to a trailer 190. The vehicle 100 is coupled to the trailer 190 by means of a tow bar 101 having a tow ball bib attached thereto as shown in FIG. 1. The trailer 190 has a coupling head 192 at a leading end of the trailer 190 by means of which the trailer 190 is coupled to the tow ball bib.

The vehicle 100 has a towing stability assessment system lOiS provided by means of a first electronic control unit (ECU) 11OA that s arranged to receive a data signal indicative of a measured nose weight of the trailer 190 from a second electronic control unit (ECU) 120A. The first ECU 11OA forms part of an nfotainment system of the vehicle 100 and is installed in a cabin of the vehicle behind a dashboard of the vehicle 100. In the embodiment of FIG. 5 the second ECU 120A is installed in a boot (trunk) of the vehicle 100. Other arrangements are also useful.

The first and second ECUS 11OA, 120A each have data processing apparatus in the form of a computing device configured to execute computer program code.

The second ECU 120A is coupled to a nose weight measuring device that is attached to the tow bar 101. In the present embodiment the nose weight measuring device is in the form of a known strain gauge 101 SG that is bonded to an outer surface of the tow bar 101.

When the coupling head 192 of the trailer 190 is lowered onto the tow ball bib, the tow bar 101 deforms elastically as the weight acting on the tow ball lOlb ncreases. A corresponding deformation of the strain gauge 1O1SG takes place. The deformation of the strain gauge 1O1SO is monitored by means of the second ECU 120A using known technology. Other nose weight measuring devices may be employed in addition or instead, such as mechanical, piezoelectric or conductvity gauges.

The second ECU 120A transmits a signal to the first ECU 11OA indicative of the measured nose weight. In the embodiment shown the signal is communicated via controller area network (CAN) bus bOB. In some alternative embodiments the signal may be communicated by wireless means, optionally by means of a short range radio link such as Bluetooth (RTM) or the like. is

FIG. 6 is a schematic illustration of the first ECU 11OA. The ECU 110A has a first input circuit Ii configured to receive data relating to the nose weight of the trailer. The first input circuit is configured to receive the nose weight data from the second ECU 120A. In some embodiments the first input circuit be arranged may be arranged to receive data relating to the nose weight of the trailer via a user interface in addition to or instead of from second ECU 120A.

The ECU 110A also has a second input circuit 12 to receive data relating to one or more nose weight conditions. In the present embodiment the second input circuit is configured to receive data relating to (a) a maximum allowable nose weight of a trailer 190, a tow bar 101 and vehicle 100; (b) a gross weight of the trailer 190; and (c) a primary allowable range of values of nose weight ratio and a secondary allowable range of values of nose weight ratio, nose weight ratio being the ratio of trailer nose weight to gross trailer weight.

The second input circuit 12 is configured to receive data items (a) to (c) from a user via a keypad displayed on a touch screen 105 of the vehicle 100. The user is prompted by the ECU 11OA to enter the data, which is then stored in a memory of the ECU 11OA. Other means allowing a user to enter the data are also useful.

It is to be understood that the first and second circuits Ii, 12 may be provided by a single data communications interface in some embodiments.

In some alternative embodiments, the second input circuit may be configured to automatically receive one or more of data items (a), (b) or (c) from another electronic control unit via a wired or a wireless communications network. For example, in some embodiments the second ECU 120A may be configured to provide a maximum allowable nose weight value for the tow bar to the first or second circuits directly, so that a user does not have to enter this data. The second ECU 120A may be configured to store the data in a memory thereof.

In some embodiments, the ECU 11OA may be pre-programmed with one or more of the maximum permissible gross weight of the trailer, the maximum permissible nose weight limit of the towing vehicle, the trailer and/or the tow bar, and/or the primary and secondary nose weight ratio ranges.

In some embodiments the ECU 1 1OA may be arranged to employ only the primary nose weight ratio range and not the secondary nose weight ratio range.

In use, the ECU 11OA is configured to allow a user to select a towing stability assessment mode of operation of the ECU 11OA via touchscreen 105. When the towing stability assessment mode is selected, the ECU 11OA allows the user to input one or more of items (a) to (c) above. In the present embodiment the ECU 11 OA is pre-programmed with the maximum allowable nose weight of the vehice 100, but allows a user to input and store the maximum allowable nose weights of the trailer and tow bar respectively. In some embodiments the ECU 11OA may be configured to allow the maximum allowable nose weight of the tow bar 101 to be pre-programmed into the ECU 1 1OA only by an authorised tow bar installer.

Once the ECU 11OA has been provided with data items (a) to (c), the ECU 11OA allows a user to command the ECU 11OA to determine, based on available information, whether a trailer 190 that is coupled to the vehicle 100 is likely to be stable when towed.

Upon receiving the user command via the touch screen 105, the ECU 11 OA reads, via the CAN bus 1 OOB, the nose weight of the trailer 192 as determined by ECU 1 20A.

The ECU 11OA then compares the measured nose weight value provided by the ECU 120A with the maximum allowable nose weight values stored by the [CU 11OA. If the measured nose weight value is greater than any of the stored nose weight values, the ECU 11OA determines that the nose weight of the trailer 190 is too high and provides a corresponding alert to the user via the touch screen 105.

If the measured nose weight value is less than each of the nose weight values stored by the ECU 11OA, the ECU 11OA determines that the measured nose weight is within an allowable range. The ECU 11OA then determines whether the measured nose weight is within a predetermined percentage of the maximum allowable nose weight value. In the present embodiment the predetermined percentage value is 15%. Other percentage values may be used such as 20%, 10% or any other suitable value.

If the ECU 11 OA determines that the measured nose weight is within the predetermined percentage range of the smaller of the stored values of maximum allowable nose weight the ECU 11OA determines that the nose weight is likely to provide moderate towing stability, subject to an assessment of the nose weight ratio. If the ECU 11OA determines that the measured nose weight is not within the predetermined percentage value of the smaller of the stored values of maximum allowable nose weight, the ECU 1 bA determines that the nose weight is likely to provide high towing stability, subject to an assessment of the nose weight ratio.

Thus, if the lower of the maximum allowable nose weight values of the vehicle 100, tow bar lOib and trailer 192 is 100kg, and the measured nose weight is 110kg, the ECU 11OA determines that the measured nose weight is too high. If the measured nose weight is 95kg and the predetermined percentage value of nose weight is 10%, the ECU 11OA determines that the nose weight ratio is within the predetermined percentage value and that towing stability is therefore likely to be moderate based on nose weight alone. If the nose weight is found to be less than 90kg, the ECU 11OA determines that the towing stability is likely to be high, based on nose weight alone.

The ECU 1 1OA then calculates the nose weight ratio by dividing the measured nose weight value by the gross weight of the trailer 190. The calculated nose weight ratio is then compared with a stored nose weight ratio range, which will be referred to as a primary nose weight ratio range. If the calculated nose weight ratio falls within the primary nose weight ratio range, the ECU 11OA determines that the calculated nose weight ratio is likely to provide high towing stability.

If the ECU 11OA determines that the calculated nose weight ratio is outside the primary nose weight ratio range, the ECU 11OA determines whether the calculated nose weight is within a secondary nose weight ratio range. If the calculated nose weight ratio is outside the primary range but inside the secondary range, the ECU 11OA determines that the calculated nose weight ratio is likely to provide moderate towing stability. If the calculated nose weight ratio is outside the primary and secondary ranges, the ECU 11OA determines that the calculated nose weight ratio is likely to provide low towing stability.

In the present embodiment, the ECU 11OA is pre-programmed with the primary and secondary nose weight ratio ranges. In the present embodiment the primary nose weight ratio range is the range from 7 to 10% and the secondary nose weight ratio range is the range from 5 to 15%. Other values of primary and secondary ranges are also useful.

The ECU 110A then generates a towing stability indication on the display 105 in dependence on the stability determination made in respect of nose weight and nose weight ratio.

If the ECU 11OA has determined that the measured nose weight exceeds a maximum permissible nose weight value of the tow bar 101, trailer 190 or vehicle 100, the ECU 11 0A generates a noseweight limit exceeded' message on the display 105.

If the ECU 11OA determines that the nose weight value and nose weight ratio both correspond to high towing stability, the ECU 11OA illuminates a lamp icon 1OSL on the display 105 that is placarded towing stability' in green colour.

If one of the nose weight and nose weight ratio has a value corresponding to high towing stability and the other has a value corresponding to moderate towing stability, the ECU 11OA illuminates the lamp icon 105L in amber colour. The lamp icon 105L is also illuminated in amber if both of the nose weight and nose weight ratios have a value corresponding to moderate towing stability.

If the nose weight value exceeds the smaller of the maximum allowable nose weight values or if the nose weight ratio is outside the primary and secondary ranges of nose weight ratios, the ECU 11 OA illuminates the lamp icon 1 OSL on the display 105 in red colour.

It is to be understood that the traffic light' indication in respect of towing stability provides a relatively intuitive guide to the likely towing stability of the trailer 190 by the vehicle 100.

In addition to the traffic light indication, the ECU 11OA also displays on the display 105 an indication of actual nose weight (in kg) and nose weight ratio.

It is to be understood that in some embodiments the ECU 11 OA may be configured to trigger generation of an audible indication in respect of nose weight and/or nose weight ratio in addition to or instead of a visual indication. This may be useful in enabUng a user to check whether the nose weight is of a value corresponding to high or moderate towing stability without needing to view the display 105, for example whilst attempting to redistribute a load on the trailer, or reduce trailer weight.

In some embodiments the ECU 11OA may be configured to provide a visual output in the form of a graph, a bar chart or one or more words to indicate the towing stability of the trailer and towing vehicle in accordance with the nose weight of the trailer.

In some embodiments, the ECU 11OA may be configured to communication with a hand-held mobile device. This has the advantage that a user may be able to obtain an assessment of towing stability when outside the vehicle, not looking at the display 105. The mobile device may be a telecommunications device such as a smart phone, a key fob or any other suitable device.

In some embodiments the ECU 11 OA may be configured to assess towing stability prior to towing, whilst the vehicle 100 is substantially stationary. However, in some embodiments the system lOiS may allow for towing stability to be assessed intermittenfly during the course of a journey. For example, the system 1015 may be configured to assess towing stability when the vehicle 100 is stationary for a sufficient period of time to allow the second ECU 120A to measure the static nose weight of the trailer 192. In some embodiments the system lOiS may further comprise a motion sensor for sensing motion of the vehicle 100 or trailer 192. The ECU 11OA may be configured to receive data intermittently during the course of a journey when the motion sensor detects that the vehicle 100 or trailer 192 is stationary for a sufficient period of time. Ths feature has the advantage that if a shift in weight distribution within the trailer 190 takes place during the course of a journey resulting in an unstable nose weight condition, a driver may be alerted to this fact.

The nose weight limit required to achieve acceptable towing stability depends on a variety of different factors including the type and weight of the trailer, the c FIG. 7 shows a vehicle 200 and trailer 290 equipped with a towing stability assessment system 2015 according to a further embodiment of the present invention. Like features of the vehicle 200 and trailer 290 of the embodment of FIG. 6 to those of the embodiment of FIG. 5 are shown with like reference numerals incremented by 100.

The embodiment of FIG. 7 differs from that of the embodiment of FIG. 5 in that the trailer 290 is provided with a trailer ECU 290A that is in wireless communication with ECU 210A of the vehicle 100 being the ECU forming part of the infotainment system. The trailer ECU 290A is connected to an antenna 295 and is configured to transmit a signal that is received by vehicle ECU 210A by means of a vehicle antenna 215.

The trailer ECU 290A is arranged to store a value of maximum permissible trailer weight (max gross weight) and a maximum allowable trailer nose weight. In the embodiment shown the maximum permissible trailer weight is 1600kg and the maximum allowable trailer nose weight is 100kg.

It is to be understood that reference herein to maximum allowable nose weight is to a maximum allowable nose weight measured under static conditions, i.e. with the trailer substantially stationary. It is to be understood that movement of the vehicle and trailer during towing can result in the actual nose weight of the trailer exceeding the static nose weight. The values of maximum allowable nose weight are set so as to allow for expected variations in actual nose weight during the course of a journey.

The ECU 290A is arranged to estimate a gross weight of the trailer 290, i.e. an actual weight of the trailer 290 including any load carried by the trailer. The ECU 290A does this by means of a strain gauge 290SG that is attached to a suspension arm of the trailer 290.

The strain gauge measures an amount of strain experienced by the suspension arm, allowing a measurement of a position of the suspension arm with respect to a reference position. From the position of the suspension arm the ECU 290A is able to estimate the gross weight of the trailer. In some embodiments, the ECU 290A may be configured to allow a reference position of the suspension arm to be stored. The reference position may be the position when the trailer 290 is substantially unladen, i.e. not having any load. The ECU 290A may then allow a set of one or more further data values to be stored, corresponding to strain experienced by the strain gauge for different loads borne by the trailer 290. In use, the ECU 290A may be configured to estimate the gross weight of the trailer based on the amount of strain experienced by the strain gauge, optionally by interpolation between data points stored by the ECU 290A.

In use, the trailer ECU 290A may be configured to allow the vehicle ECU 210A to interrogate it and to provide data requested by the vehicle ECU 210A such as maximum allowable trailer nose weight and actual traler gross weight. The trailer ECU 290A may also transmit a value of maximum allowable trailer gross weight to the vehicle ECU 210A to allow the vehicle ECU 210A to verify that actual trailer gross weight does not exceed maximum permissible trailer gross weight.

In some embodiments the value of maximum allowable trailer noseweight and optionally maximum allowable trailer gross weight may be stored by the vehicle ECU 21 0A in addition to or instead of the trailer ECU 290A.

Once the vehicle ECU 210A has obtained the value of allowable trailer nose weight and actual trailer gross weight, the vehicle ECU 210A is configured to calculate the nose weight ratio and to provide an indication to the driver in respect of towing stability in a corresponding manner to the embodiment of FIG. 5.

Some embodiments of the present invention may be understood by reference to the following numbered paragraphs: 1. A system for assessing the towing stability of a trailer and a towing vehicle comprising a first data processing unit, wherein the first data processing unit comprises: an input configured to receive data corresponding to a measured nose weight of a trailer; an electronic processor configured to determine if the measured nose weight of the trailer complies with at least one nose weight condition; and an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.

2. A system according to paragraph 1 wherein the first data processing unit is configured to receive the data corresponding to the measured nose weight of the trailer from a second data processing unit.

3. A system according to paragraph 1 wherein the first data processing unit is configured to receive the data corresponding to the measured nose weight of the trailer substantially directly from a sensor.

4. A system according to paragraph 1 wherein the first data processing unit comprises an input configured to receive data relating to the at least one nose weight condition.

5. A system according to paragraph 4 wherein the data relating to the at least one nose weight condition includes at least one nose weight limit.

6. A system according to paragraph 5 wherein the at least one nose weight condition includes the condition that the measured nose weight is less than or substantially equal to the at least one nose weight limit.

7. A system according to paragraph 5 wherein the data relating to the at least one nose weight condition includes a plurality of nose weight limits and the at least one nose weight condition includes the condition that the measured nose weight is less than or substantially equal to the smaller of the pluraUty of nose weight limits.

8. A system according to paragraph 5 wherein the data relating to at least one nose weight condition includes data relating to a ratio of nose weight to gross trailer weight.

9. A system according to paragraph 8 wherein the at least one nose weight condition includes the condition that the nose weight ratio is substantially equal to a predetermined value or that the nose weight ratio falls within a predetermined range of nose weight ratio values.

10. A system according to paragraph 9 wherein the at least one nose weight condition includes the condition that the nose weight ratio falls within a predetermined range of approximately 5% -15%, optionally approximately 5% -7%.

11. A system according to paragraph 1 wherein the output is indicative of sufficient towing stability if the measured nose weight of the trailer conforms with said at least one nose weight condition.

12. A system according to paragraph 1 wherein the output is indicative of insufficient towing stability if the measured nose weight of the trailer does not conform with one or more said at least one nose weight condition.

13. A system according to paragraph 1 wherein the output is configured to provide a visible signature and/or an audible signature to an operator indicative of towing stability.

14. A system according to paragraph 1 wherein the output is configured to produce an output indicative of the towing stability of the trailer and the towing vehicle via a hand-held mobile communications device.

15. A system according to paragraph 1 wherein the input configured to receive data corresponding to the measured nose weight of the trailer is configured to receive the data from a trailer nose weight measuring device via a wired or a wireless data communications link.

16. A system according to paragraph 4 wherein the input configured to receive data relating to the at least one nose weight condition is configured to receive the data via a wired or a wireless data communications link.

17. A system according to paragraph 1 configured to receive data relating to at least one nose weight limit from a data processor associated with a tow bar, a towing vehicle and/or a trailer.

18. A system according to paragraph 1 configured to allow data relating to a measured nose weight and/or data relating to at least one nose weight condition to be stored in a database.

19. A system according to paragraph 1 configured to allow data relating to a measured nose weight and/or data relating to at least one nose weight condition to be input manually.

20. A system according to paragraph 1 comprising measuring apparatus for measuring the nose weight of a trailer.

21. A system according to paragraph 2 comprising measuring apparatus for measuring the nose weight of a trailer and configured to transmit data relating to the measured nose weight via a wired or wireless communications link from the second data processing unit to the corresponding data input of the first data processing unit.

22. A system according to paragraph 1 comprising measuring apparatus for measuring a gross weight of a trailer and configured to transmit data relating to the measured gross weight of a trailer via a wired or wireless communications link to the corresponding data input of the first data processing unit.

23. A vehicle comprising a system according to paragraph 1.

24. A method of assessing the towing stability of a trailer and a towing vehicle comprising: receiving data corresponding to a measured nose weight of a trailer; determining if the measured nose weight of a trailer complies with at least one nose weight condition; and providing an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.

25. A method according to paragraph 24 comprising installing a system according to any one of paragraphs ito 22 in a vehicle.

26. An apparatus for assessing a vehicle: an input configured to receive data corresponding to a measured nose weight of a trailer coupled to said vehicle; a processor configured to determine if the measured nose weight of the trailer complies with at least one nose weight condition; and output means configured to produce an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.

27. A vehicle having an apparatus as claimed in claim 26.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", mean "including but not limited to", and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Claims

CLAIMS: 1. A system for assessing the towing stability of a trailer and a towing vehicle comprising a first data processor wherein the first data processor comprises: input means configured to receive data corresponding to a measured nose weight of a trailer; processing means configured to determine if the measured nose weight of the trailer complies with at least one nose weight condition; and output means configured to produce an output indicative of the towing stability of the trailer and towing vehicle in dependence on said determination.
2. A system according to claim 1 wherein the first data processor is configured to receive the data corresponding to the measured nose weight of the trailer from a second data processor.
3. A system according to claim 1 wherein the first data processor is configured to receive the data corresponding to the measured nose weight of the trailer substantially directly from sensor means.
4. A system according to any preceding claim wherein the first data processor comprises input means configured to receive data relating to the at least one nose weight condition.
5. A system according to claim 4 wherein the data relating to the at least one nose weight condition includes at least one nose weight limit.
6. A system according to claim 5 wherein the at least one nose weight condition includes the condition that the measured nose weight is less than or substantially equal to the at least one nose weight limit.
7. A system according to claim 5 or claim 6 wherein the data relating to the at least one nose weight condition includes a pluralty of nose weight limits and the at least one nose weight condition includes the condition that the measured nose weight is less than or substantially equal to the smaller of the pluraUty of nose weight limits.
8. A system according to any one of claims 4 to 7 wherein the data relating to the at least one nose weight condition includes data relating to a ratio of nose weight to gross trailer weight.
9. A system according to claim 8 wherein the at least one nose weight condition includes the condition that the nose weight ratio is substantially equal to a predetermined value or that the nose weight ratio falls within a predetermined range of nose weight ratio values.
10. A system according to claim 9 wherein the at least one nose weight condition includes the condition that the nose weight ratio falls within a predetermined range of approximately 5% -15%, optionally approximately 5% -7%.
11. A system according to any preceding claim wherein the output means is configured to produce an output indicative of sufficient towing stability if the measured nose weight of the trailer conforms with said at least one nose weight condition.
12. A system according to any preceding claim wherein the output means is configured to produce an output indicative of insufficient towing stability if the measured nose weight of the trailer does not conform with one or more said at least one nose weight condition.
13. A system according to any preceding claim wherein the output means is configured to provide a visible signature and/or an audible signature to an operator indicative of towing stability.
14. A system according to any preceding claim wherein the output means is configured to produce an output indicative of the towing stability of the trailer and the towing vehicle via a hand-held mobile communications device.
15. A system according to any preceding claim wherein the input means configured to receive data corresponding to the measured nose weight of the trailer is configured to receive the data from a trailer nose weight measuring device via a wired or a wireless data communications link.
16. A system according to claim 4 or any claim depending through claim 4 wherein the input means configured to receive data relating to the at least one nose weight condition is configured to receive the data via a wired or a wireless data communications link.
17. A system according to any preceding claim configured to receive data relating to at least one nose weight limit from a data processor associated with a tow bar, a towing vehicle and/or a trailer.
18. A system according to any preceding claim configured to allow data relating to a measured nose weight and/or data relating to at least one nose weight condition to be stored in a database.
19. A system according to any preceding claim configured to allow data relating to a measured nose weight and/or data relating to at least one nose weight condition to be input manually.
20. A system according to any preceding claim comprising measuring means for measuring the nose weight of a trailer.
21. A system according to claim 20 depending through claim 2 comprising the second data processor and transfer means for transmitting data relating to the measured nose weight via a wired or wireless communications link from the second data processor to the corresponding data input means of the first data processor.
22. A system according to any preceding claim comprising measuring means for measuring a gross weight of the trailer and transfer means for transmitting data relating to the measured gross weight of the trailer via a wired or wireless communications link to the corresponding data input means of the first data processor.
23. A vehicle comprising a system according to any preceding claim.
24. A method of assessing the towing stability of a trailer and a towing vehicle comprising: receiving data corresponding to a measured nose weight of a trailer; determining if the measured nose weight of a trailer complies with at least one nose weight condition; and providing an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.
25. A method according to claim 24 comprising installing a system according to any one of claims ito 22 in a vehicle.
26. An apparatus for assessing a vehicle: an input configured to receive data corresponding to a measured nose weight of a trailer coupled to said vehicle; a processor configured to determine if the measured nose weight of the trailer complies with at least one nose weight condition; and output means configured to produce an output indicative of the towing stability of the trailer and the towing vehicle in dependence on said determination.
27. A vehicle having an apparatus as claimed in claim 26.
28. A system, vehicle, apparatus or method substantially as hereinbef ore described with reference to any of FIGS. 5 to 8.