POWER GENERATION UNIT CONTROL FOR A TRACTOR CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.

FIELD

[0002] Embodiments of the present disclosure relate generally to systems and methods for monitoring and optionally controlling operation of a power generation unit for an agricultural vehicle, specifically in dependence on a fuel characteristic for fuel used by the power generation unit.

BACKGROUND

[0003] Traditional, "1 ^st generation" biodiesel, including FAME-type (Fatty Acid Methyl Ester) biodiesel is produced by esterifying vegetable oils or fats. The esterification process restricts the use of poor quality or impure raw materials, such as waste and residues. The quality of traditional biodiesel varies also in other respects according the raw materials used. For instance, high-quality biodiesel fuel is, on the other hand, made primarily from waste and residues. The production process can be carried out by Hydrotreatment or by Fischer-Tropsch synthesis. The resultant fuel is colorless and odorless and of an even quality that has an almost identical chemical basic composition with fossil diesel. These diesel fuels are also often called a 2 ^nd generation biofuels and some characteristics of these high quality fuels are betterwhen compared to fossil diesel, thus providing potential improvements to the combustion process for diesel engines and in particular for cold start scenarios. Other fossil diesel alternatives can be obtained using Green Hydrogen (Electricity from wind/solar/nuclear, etc.), CO2 (by-product) and Fischer-Tropsch synthesis. The resultant fuel has a similar chemical structure and emission performance to other 2nd generation diesel fuels.

[0004] Unlike other biofuels, 2nd generation high quality biodiesels can be used in high concentrations and even as a standalone (drop-in) products in all diesel engines and vehicles, with the added benefits discussed herein. For instance, whilst the general chemical structure of 2nd Generation high quality diesels and eDiesels is close to fossil diesel, such fuels have a higher Cetane number (typically 75-95) than fossil diesels (typically 50-60), which in turn results in an improved combustion process. Due to the nature of these fuels, a diesel engine burning such fuel has been shown to produce 30-50% less engine soot output, 2 - 15 % lower NOx emissions and ~ 4% lower (tail pipe) CO2 emissions. In addition, taking account the production and raw materials, the life cycle (Well-to-Wheel) CO2 emissions of these fuels can be superior - e.g. up to 90 % improvement in CO2 emissions. Further, a lower soot output in turn results in a significantly lower particulate output providing potential benefits in terms of longevity of diesel particulate filters and a lower requirement for active regeneration thereof.

[0005] It would therefore be advantageous to utilise these realized benefits for operation of an agricultural machine which is capable of being powered using multiple fuel types, variants or combinations thereof.

BRIEF SUMMARY

[0006] An aspect of the invention provides a control system for a power generation unit of an agricultural machine, the control system comprising one or more controllers, and being configured to: receive operational data indicative of a plurality of measurable operational parameters for the power generation unit; utilise a trained model to determine, in dependence on the operational parameters, a predicted fuel characteristic for fuel used by the power generation unit; and generate and output one or more control signals for controlling one or more operable components associated with the power generation unit in dependence on the predicted fuel characteristic.

[0007] Advantageously, the fuel characteristic for the machine (which may be interchangeable) can be determined automatically by the control system, and appropriate actions taken. As discussed herein, this can include controlling one or more operable components associated with the power generation unit, for example, to improve efficiency, reduce emissions and/or for other purposes, e.g. logging use of different fuel types e.g. as determined from the predicted fuel characteristic for monetary or other benefits.

[0008] The predicted fuel characteristic may be a predicted fuel type. The predicted fuel characteristic may comprise a prediction of a variant of a particular fuel type. The fuel characteristic may comprise a fuel quality parameter such as a cetane value for the fuel, for example.

[0009] The one or more operable components may comprise a data logging module. The data logging module may comprise a memory for storing data indicative of the predicted fuel characteristics, which may include a log of a usage of one or more fuel types as determined by the control system, for example. The data logging module may comprise part of the control system, or one or more further systems of the agricultural machine. In such instances, the data logging module may be hosted locally on the machine.

[0010] In other embodiments, the data logging module may comprise a remote memory means accessible by the control system. In such embodiments, the control system may comprise or may be communicably coupled to a communication module for accessing the remote memory means over a network, (e.g. over a wireless data connection).

[0011] Advantageously, a data logging module may be used to log an amount or proportion of time spent or fuel used for particular fuel types. This may be used, for example, to track usage of fuel types with lower associated emissions by the machine, which in turn could be used to evidence such usage for monetary or other incentives for the operator.

[0012] The one or more operable components may comprise an exhaust after treatment system. The control system may be configured for controlling operation of the exhaust after treatment system, for example, through control over the timing and/or volume of exhaust fluid (e.g. AdBlue®) supplied by the after treatment system module as appropriate for the predicted fuel characteristic. Accordingly, embodiments of the control system are suitably configured to control the exhaust after treatment system to improve efficiency in terms of time and cost for fuel types or variants requiring less after treatment and reduction in wear and tear for the exhaust after treatment system as a whole.

[0013] The one or more operable components may include a regeneration system associated with the exhaust system of the machine. The exhaust system may, for instance include a particulate filter which may be cleared or "regenerated" by the regeneration system during a regeneration event. The control system may be configured for controlling operation of the regeneration system, for example, through control over the interval between regeneration events, and/or the duration of regeneration events as appropriate for the fuel type / characteristic determined by the control system. As will be appreciated, use of different fuel types may ultimately result in differing particulate levels which in turn leads to different operating requirements for the regeneration system. Where a fuel characteristic is determined which is indicative of a slower buildup of particulate material on the filter, the control system may extend the interval between consecutive regeneration events to realise improvements in efficiency associated therewith.

[0014] The one or more operable components may comprise one or more operable components of the power generation unit. In embodiments, the one or more operable components may include an engine management module operable, in turn, to control one or more working parameters of the power generation unit. The control system may be configured to control operation of the engine management module for controlling one or more injection parameters in dependence on the predicted fuel characteristic. The one or more injection parameters may include an injection timing. The one or more injection parameters may include an injection profile or distribution across a given power cycle (e.g. engine stroke) for the power generation unit. Advantageously, the control system may be operable to control operation of the power generation unit in dependence on the predicted fuel characteristic in an attempt to minimize an emission level associated with the operation of the power generation unit.

[0015] In further embodiments, the control system may be operable to prevent operation of the power generation unit in dependence on the predicted fuel characteristic. For example, where a predicted fuel characteristic is indicative of the use of a given fuel type which may be harmful or damage the power generation unit, the control system may be configured to prevent further operation of the power generation unit with that fuel type.

[0016] In embodiments, the control system may be operable to control operation of a user interface. The user interface may comprise a display terminal associated with the agricultural machine, such as a fixed display terminal within an operator cab of the agricultural machine. In other embodiments, the user interface may comprise a display screen of a remote user device, such as a tablet computer, laptop computer or the like. The control system may be operable to control operation of the user interface for displaying or otherwise communicating to an operator of the machine, an indication of the predicted fuel characteristic.

[0017] The measureable operational parameters may comprise a measure of a pressure, temperature or gas level associated with operation of the power generation unit. The measureable operational parameters may include a measure of a level of nitrous oxide (NOx) or oxygen (O2) associated with operation of the power generation unit, e.g. present within fluid present within one or more operating chambers of the power generation unit.

[0018] The control system may be operable to receive operational data from one or more sensors of the power generation unit and/or agricultural machine indicative of the measureable operational parameter(s). The sensor(s) may comprise sensors utilised for monitoring operation of various operational characteristics of the power generation unit and/or agricultural machine. Advantageously, the present invention may utilise pre-existing sensing technology without requiring the addition of a dedicated sensor or sensors for predicting the fuel characteristic, which would otherwise increase cost and complexity of the system.

[0019] The measureable operational parameters may comprise a measure of one or more engine operating point parameters. The measureable operational parameters may comprise one or more calculated variables.

[0020] The operational parameters may include any one or more selected from a group of: a temperature value, a pressure value, a gas concentration level, an operational speed of one or more operable components of the machine, a volume measurement, a torque measurement, etc. For example, the operational parameters may include an exhaust back pressure, a rail pressure, a boost pressure, a manifold upstream temperature, a diesel oxidation catalyst (DOC) upstream temperature, an oil temperature, a temperature upstream and/or downstream of a selective catalytic reduction (SCR) system, a temperature upstream or downstream of a diesel particulate filter (DPF), a coolant temperature, an exhaust mass flow, a NOx concentration, an oxygen concentration, injection parameters including a desired timing, a current injection quantity, a desired injection quantity, an engine speed and/or an engine torque. It will be appreciated that this list is not exhaustive, but may provide multiple inputs to the trained model for determining the predicted fuel characteristic.

[0021] The trained model may comprise a model of the relationships between each of the plurality of operating parameters for different fuel characteristics and/or under different operating conditions for the power generation unit and/or the agricultural machine. The training model may employ a hierarchical model, such as a decision tree or an ensemble method employing multiple decision trees. The training model may comprise a random forest model. The training model may comprise a Classification and Regression Trees (CART) model. [0022] The control system, or one or more components thereof, e.g. the one or more controllers, may be configured to access a storage means to retrieve data indicative of the trained model. The storage means may be a local storage means, such as a memory of the control system. The storage means may comprise a remote server. The trained model may be generated prior to operation of the control system. This may be referred to as the model being generated during a "training phase". For instance, the model may be generated and stored at a remote server for subsequent retrieval by control system(s) associated with the power generation unit. The training phase may include performance of an agricultural operation in a laboratory or test conditions with a variety of known fuel types or variants with given characteristics and analyzing the relationships between each of the plurality of operating parameters for different fuel types and/or variants and/or under different operating conditions for the power generation unit and/or the agricultural machine.

[0023] The trained model may comprise a base model for the control system. The control system may be configured to update the base model upon future generation of fuel characteristic predictions.

[0024] The control system may be operable to determine a confidence value for the predicted fuel characteristic. The confidence value may quantify a confidence level for the prediction. The control system may be operable to compare the confidence value with a threshold confidence value. The control system may be operable to generate and output the control signal(s) in dependence on the comparison. For example, in some embodiments the control system may be operable to automate control of the one or more operable components in dependence on the determined confidence value exceeding the threshold confidence value.

[0025] The control system may be operable to control operation of a user interface associated with the agricultural machine in dependence on the determined confidence value being less than the threshold confidence value. Advantageously, the control system may present a predicted fuel characteristic to an operator of the machine where the accuracy of the prediction is determined to be lower than an acceptable level. In embodiments, the control system may be operable to receive, e.g. via the user interface, an operator input indicative of the fuel characteristic used for the power generation unit. Advantageously, this may comprise a confirmatory input by an operator of the machine to confirm the predicted fuel characteristic. The control system may be operable to initiate control of the one or more operable components in dependence on receipt of the confirmatory operator input.

[0026] The one or more controllers may collectively comprise an input (e.g. an electronic input) for receiving one or more input signals indicative of the operating parameters. The one or more controllers may collectively comprise one or more processors (e.g. electronic processors) operable to execute computer readable instructions for controlling operation of the control system, for example to determine, from the received parameters, a predicted fuel characteristic for the power generation unit. The one or more processors may be operable to generate one or more control signals for controlling operation of the one or more operable components according to the predicted fuel characteristic. The one or more controllers may collectively comprise an output (e.g. an electronic output) for outputting the one or more control signals.

[0027] According to a further aspect of the invention there is provided a power generation unit comprising and/or being controllable under operation of a control system as described herein.

[0028] A further aspect of the invention provides an agricultural machine comprising the power generation unit and/or the control system of any preceding aspect.

[0029] According to a further aspect of the invention there is provided a method of monitoring operation of a power generation unit of an agricultural machine, comprising: receiving operational data indicative of a plurality of measurable operational parameters for the power generation unit; utilising a trained model to determine, in dependence on the operational parameters, a predicted fuel characteristic used by the power generation unit; and controlling one or more operable components associated with the power generation unit in dependence on the predicted fuel characteristic.

[0030] The method of the present aspect of the invention may comprise performance of any one or more of the functional features of the control system of a preceding aspect discussed herein.

[0031] A further aspect of the invention comprises computer software which, when executed by one or more processors, causes performance of the method of the preceding aspect of the invention.

[0032] An aspect of the invention provides a computer readable storage medium comprising the computer software of the preceding aspect of the invention. [0033] Within the scope of this application it should be understood that the various aspects, embodiments, examples and alternatives set out herein, and individual features thereof may be taken independently or in any possible and compatible combination. Where features are described with reference to a single aspect or embodiment, it should be understood that such features are applicable to all aspects and embodiments unless otherwise stated or where such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] One or more embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0035] FIG. l is a simplified cross-sectional side view illustrating a tractor embodying aspects of the present disclosure;

[0036] FIG. 2 is a schematic illustration of an embodiment of a control system of the disclosure;

[0037] FIG. 3 is a flowchart illustrating an embodiment of a method in accordance with the disclosure;

[0038] FIG. 4 is a schematic illustration of aspects of the disclosure;

[0039] FIG 5 is a graph illustrating aspects of the present disclosure;

[0040] FIGs 6A and 6B show experimental data for a given scenario illustrating measureable operable parameters for standard diesel (FIG 6A) and HVO (FIG 6B); and

[0041] FIG 7 illustrates operational parameters for a given power unit and its variance for different injection timings for different fuel types.

DETAILED DESCRIPTION

[0042] Control systems and methods are provided for monitoring and optionally controlling operation of a power generation unit, e.g. power unit 54 of an agricultural machine, e.g. tractor 50. As discussed herein, operational data indicative of a plurality of measurable operational parameters for the power unit 54 is used to predict a fuel characteristic used by the power unit 54. Specifically, a trained model is used with the operational parameters as inputs thereto to determine a predicted fuel characteristic for the power unit 54. Advantageously, the fuel characteristic can be used to control aspects of operation of the power unit 54 or operable components associated therewith, e.g. a data logger 30 and/or user interface 32, accordingly. This may be used to ensure appropriate operating parameters or conditions for the power unit 54 for the predicted fuel characteristic, and/or can include logging a usage of specific fuel types, e.g. higher quality fuels, different generation diesel fuels, etc. for monetary or other incentives. This can include utilising the user interface 32 to provide an indication to an operator of the machine of the determined fuel characteristic - e.g. a notice / warning where low fuel quality is determined. Additionally or alternatively this can include preventing operation of the power unit 54 in dependence on the fuel characteristic - e.g. where an unsuitable or low quality fuel type is determined.

System

[0043] With reference to FIG. 1, an agricultural machine in the form of a tractor 50 is shown which embodies aspects of the invention.

[0044] Tractor 50 includes a power generation unit in the form of power unit 54 for providing (primarily) motive power to wheels 56 to propel the tractor 50. It will be appreciated that the power unit 54 may additionally power operative implements coupled to the tractor 50, e.g. via operation of a power take off shaft or the like. Tractor 50 additionally includes an operator cab 58 having, amongst other things, a user interface 32 for providing information to an operator of the tractor 50 information indicative of the tractor operation. In addition, the user interface 32 is configured for receiving (and transmitting) operator inputs in relation to the operation of the tractor 50, e.g. to adjust fluid pressure levels associated with operable components of the tractor 50 for performing an agricultural task.

[0045] Tractor 50 is provided with a controller 2 forming part of embodiments of a control system 1 of the invention - discussed in detail below. The controller 2 is hosted on board the tractor 50 and is therefore considered a local control unit. However, in alternative arrangements, one or more components of the control system 1 may be located remote from the tractor 50, including memory means, servers, processing modules etc.

[0046] It will be appreciated that the tractor 50 is shown as an example only. Aspects of the invention discussed herein have applications across multiple machines, including harvesting machines, seeding and spraying equipment, etc. In further extensions of the present disclosure, the machine may be a working machine, which may not necessarily be an agricultural machine, such as a commercial vehicle, construction machine, etc.

Control System

[0047] As discussed herein, a control system 1 is provided and configured to controlling operation of one or more operable components (e.g. data logger 30, power unit controller 52 user interface 32) associated with power unit 54 of tractor 50. In the illustrated embodiment the controllable components include a data logger 30 for logging use of fuels with different fuel characteristics for the power unit 54, a user interface 32 associated with the tractor 50, here provided as a display terminal of the tractor 50, or could equally be a handheld terminal or the like to provide an indication of the operation of the control system 1 and/or to receive one or more operator inputs for controlling operation of the control system 1 in the manner described herein, and a control unit 52 of the power unit 54 for controlling one or more operational parameters of the power unit 54 in dependence on the predicted fuel characteristic, determined in the manner discussed herein.

[0048] FIG 2 illustrates the control system 1 further. As shown, control system 1 comprises a controller 2 having an electronic processor 4, electronic input 6 electronic outputs 8, 12 and electronic input/output 10. The processor 4 is operable to access a memory 14 of the controller 2 and execute instructions stored therein to perform the steps and functionality of the present invention discussed herein, e.g. by controlling the data logger 30 to log use of particular fuel characteristics as determined by control system 1, and/or controlling a user interface 32 to display information indicative of predicted fuel characteristic and/or to receive an operator input for confirmation of a predicted fuel characteristic or to initiate an action based on the predicted fuel characteristic, through generation and output of one or more control signals.

[0049] Processor 4 is operable to receive via input 6 which, in the illustrated embodiment, takes the form of input signals 5 received from a control unit associated with a plurality of sensing units 29a, 29b, 29c etc. associated with the tractor 50, data indicative of the operational parameters associated with the power unit 54 as sensed by sensing units 29a, 29b, 29c. As discussed herein, in use, the sensing units 29a, 29b, 29c etc. are configured to measure, for example, a pressure, temperature or gas level associated with operation of the power unit 54. For instance, sensor 29a may comprise a temperature sensor for sensing an operating temperature associated with the power unit 54. Sensor 29b may comprise a pressure sensor for sensing an operating pressure associated with the power unit 54. Sensor 29c may comprise a gas sensor for sensing a concentration or absolute level of a particular gas generated by the power unit 54 during operation. Sensor 29c may comprise a NOx or O2 sensor, for example. Utilising this data, the processor 4 is operable to analyse the data and determine therefrom a predicted fuel characteristic for the power unit 54 in the manner discussed herein, e.g. using the learned model for the monitored operation. Example parameters which may be measured and used as inputs for the learned model may include any one or more of: an exhaust back pressure, a rail pressure, a boost pressure, a manifold upstream temperature, a diesel oxidation catalyst (DOC) upstream temperature, an oil temperature, a temperature upstream and/or downstream of a selective catalytic reduction (SCR) system, a temperature upstream or downstream of a diesel particulate filter (DPF), a coolant temperature, an exhaust mass flow, a NOx concentration, an oxygen concentration, injection parameters including a desired timing, a current injection quantity, a desired injection quantity, an engine speed and/or an engine torque. It will be appreciated that this list is not exhaustive, but may provide multiple inputs to the trained model for determining the predicted fuel characteristic.

[0050] FIGs 6A and 6B are illustrative of experimental data obtained for multiple operational parameters measured during multiple operational cycles of a power unit utilising fuel in the form of standard diesel (FIG 6A) and HVO (FIG 6B). Whilst scenario dependent, it can be seen that different operational parameters may exhibit different behaviors, levels, etc. depending on the type of fuel or other fuel characteristic associated with the fuel type used. One example shown here is that in the measured scenario the exhaust back pressure has been measured higher when using HVO when compared with standard diesel. Another difference in this particular scenario is the manifold temperature, which was measured in this instance to be higher when using HVO when compared with standard diesel. The measurements of these parameters and multiple others are fed into the learned model for determining the predicted fuel characteristic therefrom. It will be appreciated and is discussed in detail herein that each of these parameters are dependent on many factors and as such multiple different measured parameters are desirable to produce a more accurate prediction of the fuel characteristic. Accordingly, the present invention is configured to analyse multiple inputs are their interdependence to produce the prediction. [0051] As described above, the controller 2 includes an electronic output 8 configured to output control signals 9 generated by the processor 4 for controlling operation of one or more operable components associated with the power unit 54 and/or tractor 50. Specifically, in the illustrated embodiment, the processor 4 is operable to generate, and the controller 2 operable then to output via output 8, control signals 9 to local control unit 52 of the power unit 54 for controlling operable parameters thereof in a manner suited to a fuel type or variant with the predicted fuel characteristic. In practice, this may include adjusting an injection timing, for example. Controller 2 additionally includes an electronic output 12 for outputting control signals 13 to data logger 30 for logging / tracking usage of different fuel types by the power unit 54.

[0052] Input/output 10 is operably connected to user interface 32. The control system 1 is operable to control operation of the user interface 32, e.g. through output of control signals 11 in order to display data to an operator of the tractor 50 indicative of the predicted fuel characteristic, as determined by processor 4. This can include simply providing an indication to the operator of the predicted fuel characteristic, or prompt the operator to confirm the predicted fuel characteristic. As discussed herein, in response to an operator confirming the predicted fuel characteristic, further actions may be taken by the control system 1 according to the confirmed fuel characteristic, e.g. utilising data logger 30 and/or controlling the power unit 54 accordingly in the manner discussed herein. For this purpose, the input/output 10 is additionally configured to receive input signals 11 from the user interface 32 indicative of an operator input at the user interface 32.

[0053] In an extension of the illustrated embodiment, the control system 1 and in particular the controller 2 may include an additional output for outputting control signals for controlling operation of an exhaust after treatment system of the tractor 50. Advantageously, and as discussed herein, control over the exhaust after treatment system may include control over the timing and/or volume of exhaust fluid supplied by an after treatment system as appropriate for the predicted fuel characteristic to improve efficiency in terms of time and cost for fuel types or variants requiring less after treatment and reduction in wear and tear for the exhaust after treatment system as a whole.

[0054] In a further extension, the control system 1 and in particular the controller 2 may include an additional output for outputting control signals for controlling operation of a regeneration system associated with a particulate filter system of the tractor 50. Advantageously and as discussed herein, control over the regeneration system may include control over the timing of a regeneration event performed by the regeneration system for the particulate filter system as appropriate for the predicted fuel characteristic. Advantageously, for example, for certain fuel types the interval between regeneration events may be lengthened compared with other fuel types, realising improvements in fuel consumption associated with performance of such events.

Method

[0055] FIG. 3 illustrates a method 100 in accordance with the present disclosure. Method 100 comprises, at step 102, receiving operational data indicative of measureable operational parameters for the power unit 54. As discussed herein, this comprises receiving, from sensing units 29a, 29b, 29c data indicative of various operational parameters associated with the power unit 54, including a temperature, pressure and/or gas level associated with the power unit's operation.

[0056] At step 104, a trained model is used to determine, based on the operational parameters, a predicted fuel characteristic for fuel used by the power unit 54. The trained model comprises a model of the relationships between each of the plurality of operating parameters for different fuel characteristics and/or under different operating conditions. Here, this includes (optionally amongst other things) a model of the relationships between operating temperatures and pressures for different fuel characteristics, along with an expected gas level/concentration expected for a given combustion process associated with different fuel characteristics. The training model employs a hierarchical model into which the operational parameters are input for determining the predicted fuel characteristic. This is illustrated schematically in FIG. 4, where each decision node represents a decision based on a comparison of the received operational parameter with, for example, learned operational ranges for said parameters for particular fuel characteristics under particular operating conditions. An output is given indicative of the predicted fuel characteristic, and this may be done once a confidence value associated with the respective decision node reaches or exceeds a threshold confidence value. FIG. 5 provides an example which graphically illustrates how the confidence value for a given fuel characteristic increases with the number of operational parameters assessed / utilised as inputs to the trained model. [0057] The trained model is stored in a memory means, e.g. memory 14 of the control system 1 or a remote server. The model is generated during a "training phase", prior to performance of method 100. The training phases include performance of an agricultural operation in a laboratory or test conditions with a variety of known fuel characteristics and analyzing the relationships between each of the plurality of operating parameters for different fuel characteristics and/or under different operating conditions for the power unit 54. In an extension of the method 100, the trained model may comprise a base model for the control system 1, which can be updated upon future generation of fuel characteristic predictions, including utilising operator confirmation of the predicted fuel characteristic during operational use of the tractor 50.

[0058] The output from the model here triggers control over the one or more operable components associated with the power unit 54. In the illustrated embodiment, the method 100 includes three potential steps once a determination of the predicted fuel characteristic has been made.

[0059] At step 106A the predicted fuel characteristic is logged, e.g. utilising data logger 30 in the manner discussed herein, to log a time and/or volume of usage of a particular fuel with the predicted characteristic(s). This may, in an optional step 108, be used to calculate a level of CO2 emissions associated with use of a specific fuel type, specific to the operation of tractor 50. This can be determined through use of an average CO2 emission per unit time, per unit power, or unit volume of the given fuel type. Logging use of particular fuel types can be used by the operator or owner of the tractor 50 as evidence to support claims for monetary or other incentives or benefits, for example, or used to track use of lower carbon technologies for offsetting purposes and the like.

[0060] At step 106B, the predicted fuel characteristic is used to control operation of an exhaust after treatment system of the tractor 50. The exhaust after treatment system typically regeneration system utilises an after treatment, such as a diesel exhaust fluid (e.g. AdBlue®) for reduction in NOx emissions. Here, the method 100 comprises controlling operation of the exhaust after treatment system through control over the timing and/or volume of the after treatment fluid supplied by an after treatment regeneration system as appropriate for the predicted fuel characteristic. Advantageously, improvements in efficiency in terms of time and cost for fuel types requiring less after treatment and reduction in wear and tear for the exhaust after treatment system as a whole can be realized. [0061] In a variant, some machines may utilise a Diesel Particulate Filter system having a particulate filter for reducing particulate emissions and a regeneration system for periodically clearing the particulate filter during a regeneration event. During a regeneration event, the engine airflow is decreased and extra fuel is injected into the exhaust system. Accordingly, such events results in a temporary increase in fuel consumption. However, it is known that for particular fuel types/characteristics, the particulate build up on the particulate filter may be slower or quicker depending on the fuel type. For instance, it has been shown in the field that the use of HVO compared with standard "market" diesel demonstrates a slower build-up of particulates on a particulate filter. Accordingly, the present invention may be configured, upon prediction of the use of HVO, to extend the interval between regeneration events to realise these potential improvements in efficiency.

[0062] At step 106C, the predicted fuel characteristic is used to adjust operational parameters of the power unit 54 itself. Here, this includes controlling an injection timing, or other fuel injection parameters, including volume or distribution across a given engine stroke, for example, based on the predicted fuel characteristic. For example, it has been shown in the field - see FIG 7 - that operational factors for a power unit including Fuel Consumption/CO2 emissions, CO emissions, NOx emissions, etc. vary with both injection timing and fuel type - between HVO and "Market" diesel. Accordingly, upon prediction of a given fuel characteristic, and specifically here the fuel type it may be possible to adjust the injection timing / crank angle to achieve a desired level / measure for such parameters. For instance, in one example, it may be desirable to minimize NOx emissions by adjusting Main Injection Timing (see FIG 7). If it is predicted that the fuel characteristic, here fuel type is HVO then it may be possible to adjust the Injection Timing further to realise greater reduction in NOx output whilst still maintaining an acceptable Fuel Consumption when compared with use of "Market" diesel, which is shown to increase with said adjustment in the Injection Timing (FIG 7). Additionally or alternatively it may be possible to adjust the Injection Timing to maintain an acceptable NOx output but at the same time reducing fuel consumption and/or reduced CO2 emissions. In this way, the present invention utilises this to adjust operational parameters of the power unit 54 based on the predicted fuel characteristic to realise operational improvements.

General [0063] Any process descriptions or blocks in flow diagrams should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included within the scope of the embodiments in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present disclosure.

[0064] It will be appreciated that embodiments of the present invention can be realized in the form of hardware, software or a combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape. It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs that, when executed, implement embodiments of the present invention. Accordingly, embodiments provide a program comprising code for implementing a system or method as set out herein and a machine readable storage storing such a program. Still further, embodiments of the present invention may be conveyed electronically via any medium such as a communication signal carried over a wired or wireless connection and embodiments suitably encompass the same.

[0065] All references cited herein are incorporated herein in their entireties. If there is a conflict between definitions herein and in an incorporated reference, the definition herein shall control.