Vehicle engine cranking

Abstract

A control system 200 for a vehicle (10, Fig. 1B), comprising one or more controllers 201, and configured to determine that a high voltage electric motor starting device (18, 24, Fig. 1B) start of an e

Description

TECHNICAL FIELD The present disclosure relates to vehicle engine cranking. In particular, but not exclusively, it relates to a control system, vehicle, method, and computer software for vehicle engine cranking. 5 BACKGROUND An engine of a vehicle can be cranked to start the engine. However, cranking in order to start the engine may not be done intelligently or efficiently. 10 It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide a control system, a vehicle, a method and computer software as claimed in the appended claims. 15 According to an aspect of the invention there is provided a control system for a vehicle, the control system comprising one or more controllers, wherein the control system is configured to: determine that a high voltage electric motor starting device start of an engine of the vehicle is to be performed; LO determine an amount of torque to be provided during the high voltage electric motor starting device start of the engine; CXJ20 determine an amount of torque available from at least one high voltage electric motor starting device of the vehicle; cranking the engine using the at least one high voltage electric motor starting device; and controlling a throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of an engine in dependence on the amount of torque to be provided during the high voltage electric motor starting device start of the । engine and the amount of torque available from the at least one high voltage electric motor starting device. ^25 This provides the advantage that the amount of air in the combustion chambers of the engine can be controlled to allow efficient starting of the engine. For example, the engine can benefit from low pumping losses by having lower pressure in the intake manifold and combustion chamber during compression and exhaust stroke of a four stroke cycle, providing efficient starting of the engine. 30 This also provides the advantage that a start of an engine / engine start with a closed throttle valve is possible. For example, this can ensure that the engine benefits from low pumping losses by ensuring low pressure in intake manifold and combustion chamber during compression and exhaust stroke of a four stroke cycle, providing efficient starting of the engine. 35 In some examples, the control system is configured to determine a difference between the amount of torque to be provided during the high voltage electric motor starting device vehicle start of the engine and the amount of torque available from the at least one high voltage electric motor starting device, wherein controlling the throttle valve comprises controlling the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the engine in dependence on the difference. 40 This provides the advantage that the throttle valve can be controlled in dependence on the amount of engine torque required from combustion of fuel (if any). In some examples, the control system is configured to determine that the at least one high voltage electric motor starting device can provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine, and wherein controlling the throttle valve of the engine comprises closing the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start. This also provides the advantage that the engine benefits from low pumping losses by having low pressure in intake manifold and combustion chamber during compression and exhaust stroke. In some examples, the control system is configured to determine that the at least one high voltage electric motor starting device cannot provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine, and wherein controlling the throttle valve of the engine comprises at least partially opening the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start to provide engine torque during the high voltage electric motor starting device start in dependence on the determination. This provides the advantage that engine torque from combustion of fuel can be provided during engine start if needed, but a throttle valve can be intelligently controlled to provide efficient engine start by allowing lower pressure in intake manifold and combustion chamber during compression and exhaust stroke of a four stroke cycle. In some examples, the control system is configured to determine an engine torque request prior to and / or during the high voltage electric motor starting device start of the engine and to control the throttle valve of the engine in dependence on the determined engine torque request. This provides the advantage that engine torque requests, such as driver demand, will be met. In some examples, determining an amount of torque to be provided during the high voltage electric motor starting device start of the engine comprises determining at least one engine parameter. In some examples, determining an amount of torque available from the at least one high voltage electric motor starting device comprises determining at least one of: a state of health of the at least one high voltage electric motor starting device; a state of health of a high voltage system of the vehicle; and input from battery management system of the vehicle. In some examples, the at least one high voltage electric motor starting device comprises an integrated starter generator. In some examples, the one or more controllers collectively comprise: at least one electronic processor having an electrical input for receiving information associated with vehicle engine cranking; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to perform and / or cause performance of any one or more methods described herein. According to a further aspect of the invention there is provided a vehicle comprising a control system as described herein and an engine and at least one high voltage electric motor starting device configured to start the engine. 5 According to a further aspect of the invention, there is provided a method of cranking an engine of a vehicle, the method comprising: determining that a high voltage electric motor starting device start of an engine of the vehicle is to be performed; determining an amount of torque to be provided during the high voltage electric motor starting device start of the engine; 10 determining an amount of torque available from at least one high voltage electric motor starting device of the vehicle; cranking the engine using the at least one high voltage electric motor starting device; and controlling a throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the engine in dependence on the amount of torque to be provided during the high voltage electric motor starting device start of the engine and the amount of torque available from the at least one high voltage electric motor starting device. In some examples, the method comprising: determining a difference between the amount of torque to be provided during the high voltage electric motor starting device vehicle start of the engine and the amount of torque available from the at least one high voltage electric motor starting device, wherein controlling the throttle valve comprises controlling the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the engine in dependence on the difference. In some examples, the method comprising: determining that the at least one high voltage electric motor starting device can provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine, and wherein controlling the throttle valve of the engine comprises closing the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start. 0^25 In some examples, the method comprising: determining that the at least one high voltage electric motor starting device cannot provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine, and wherein controlling the throttle valve of the engine comprises at least partially opening the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start to provide engine torque during the high voltage electric motor 30 starting device start in dependence on the determination. In some examples, the method comprising: determining an engine torque request prior to and / or during the high voltage electric motor starting device start of the engine and to control the throttle valve of the engine in dependence on the determined engine torque request. According to a further aspect of the invention there is provided computer software that, when executed, is arranged to perform any one or more of the methods described herein. According to a further aspect of the invention there is provided computer software that, when executed, is arranged to perform any one or more of the methods described herein. 21 03 25 According to a further aspect of the invention there is provided a non-transitory computer readable medium comprising computer readable instructions that, when executed by one or more electronic processors, causes the one or more electronic processors to carry out any one or more of the methods described herein. 5 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 falls within the scope of the appended claims. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination that falls within the scope of 10 the appended claims, 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. 15 BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 20 FIG. 1A illustrates an example of a vehicle; FIG. 1B illustrates an engine and related components of the vehicle; FIG. 2A and 2B illustrate an example of a control system and of a non-transitory computer readable storage medium; FIG. 3 illustrates an example of a method; and FIG. 4 illustrates an example of engine starting strategy. 25 DETAILED DESCRIPTION FIG. 1A illustrates an example of a vehicle in which embodiments of the invention can be implemented. In some, but not necessarily 30 all examples, the vehicle is a passenger vehicle, also referred to as a passenger car or as an automobile. In other examples, embodiments of the invention can be implemented for other applications, such as commercial vehicles. FIG. 1A is a front perspective view and illustrates a longitudinal x-axis between the front and rear of the vehicle representing a centreline, an orthogonal lateral y-axis between left and right lateral sides of the vehicle, and a vertical z-axis. A forward / fore 35 direction typically faced by a driver’s seat is in the negative x-direction; rearward / aft is +x. A rightward direction as seen from the driver’s seat is in the positive y-direction; leftward is -y. These are a first lateral direction and a second lateral direction. The vehicle 10 comprises a control system 200 comprising one or more controllers (see, for example, 2A) configured to control one or more functions and / or features of the vehicle 10. In the example of FIG. 1B, the vehicle comprises an engine 12, which can be considered an internal combustion engine. The vehicle 10 can comprise any suitable engine or engines 12. For example, the vehicle 10 can comprise any suitable internal combustion engine, such as a petrol or diesel internal combustion engine, which is configured to be cranked to start the engine. In the example of FIG. 1B, the vehicle 10 also comprisesan electronically controlled throttle valve 20 configured to control airflow into the engine 12. FIG. 1B also illustrates a starter motor 26 in the form of a pinion starter. This is an example of a low voltage electric motor starting device, as the starter motor 26 may be configured to operate at a voltage less than or equal to 12 volts or 24 volts. In the example of FIG. 1B, the vehicle 10 comprises at least one high voltage electric motor starting device 18, which, in the illustrated example, comprises an integrated starter generator (ISG) 24 or other electric motor / generator, configured to crank the engine 12. FIG 2A illustrates a control system 200 as described herein. The control system 200 is configured to implement, at least part of, any one or more of the methods described herein. FIG. 2A illustrates an example control system 200 configured to implement one or more aspects of the invention. The control system 200 of FIG. 2 comprises a controller 201. In other examples, the control system 200 may comprise a plurality of controllers on-board and / or off-board the vehicle 10. In examples, any suitable control system 200 can be used. The controller 201 of FIG. 2A includes at least one processor 204; and at least one memory device 206 electrically coupled to the electronic processor 204 and having instructions (e.g. a computer program 208) stored therein, the at least one memory device 206 and the instructions configured to, with the at least one processor 204, cause any one or more of the methods described herein to be performed. The controller 201 may have an interface 202 comprising an electrical input / output I / O 210, 212, or an electrical input 210 / an electrical output 212, for receiving information and interacting with external components. FIG. 2A therefore illustrates a control system 200, wherein the one or more electronic controllers 201 collectively comprise: at least one electronic processor 204 having an electrical input 210 for receiving information associated with vehicle engine cranking; and at least one electronic memory device 206 electrically coupled to the at least one electronic processor 204 and having instructions 208 stored therein; and wherein the at least one electronic processor 204 is configured to access the at least one memory device 206 and execute the instructions thereon so as to cause the control system 200 to perform and / or cause performance of any one or more methods described herein. Also illustrated in the example of FIG 2A, are one or more input devices 214. In some examples, the one or more input devices 214 comprise one or more vehicle systems. 21 03 25 Information can be communicated between the one or more input devices 214 and the control system 200 and / or controller 201. There can be any number of intervening elements between the one or more input devices 214 and the control system 200 (including no intervening elements). 5 In examples, the input device(s) 214 can comprise any suitable input device(s) 214, for example any suitable vehicle system(s). For example, the input device(s) 214 can comprise one or more systems and / or at least one element of one of one or more systems involved in the engine cranking. 10 In examples, the input device(s) 214 can comprise any suitable input device(s) 214 from which information can be received that can be used in one or more methods described herein. Also illustrated in the example of FIG. 2A are one or more output devices 216. 15 The one or more output devices 216 can comprise any suitable output device(s) 216 having any suitable form. For example, the at least one or more output devices 216 can comprise one or more actuators, one or more displays, one or more separate devices and so on. 20 In examples, at least one or more output devices 216 can be used to provide information to a user, such as a driver, of the vehicle 10. FIG. 2B illustrates a non-transitory computer-readable storage medium 218 comprising the instructions (computer software). 25 Accordingly, FIG. 2B illustrates a non-transitory computer-readable storage medium 218 comprising computer readable instructions 208 that, when executed by a processor, 204, cause performance of at least method of one or more of FIG. 3, and / or FIG. 4, and / or as described herein. FIG. 3 illustrates an example of a method 300 of cranking an engine 12 of a vehicle 10. 30 In examples, the method 300 is performed by the control system 200 of FIGS 2A, 2B. That is, in some examples, the control system 200 described herein comprises and / or provides means for performing the method 300. However, any suitable means may be used to perform method 300. 35 In examples, method 300 can be considered a computer implemented method 300 for a vehicle 10, such as the vehicle 10 of FIG. 1A. One or more of the features discussed in relation to FIG. 3 can be found in one or more of the other figures. 40 At block 302, method 300 comprises determining that a high voltage electric motor starting device start (e.g., ISG start / e-machine start) of an engine 12 of the vehicle 10 is to be performed. 21 03 25 As used herein, the term “determining” (and grammatical variants thereof) can include, at least; calculating, computing, processing, deriving, investigating, looking up (for example, looking up in a table, a data base or another data structure), ascertaining and the like. Also, “determining” can include receiving (for example, receiving information), accessing (for example, accessing data in a 5 memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing, and the like. Determining that an e-machine start of an engine 12 of the vehicle 10 is to be performed can be performed in any suitable way using any suitable method. 10 In some examples, determining that an e-machine start of an engine 12 of the vehicle 10 is to be performed comprises receiving one or more inputs, such as one or more signals indicating that an e-machine start of an engine 12 of the vehicle 10 is to be performed. One or more inputs can be received from any suitable source(s). For example, one or more inputs can be received from / result 15 from a user of the vehicle 10 and / or from one or more systems of the vehicle 10. In examples, an e-machine start of an engine 12 of the vehicle 10 can be considered a start, and / or attempted start, and / or cranking, of an engine 12 of the vehicle 10 by any suitable electric machine such as the ISG 24, other than the starter motor 26. 20 An ISG 24 can be considered any suitable high voltage electric device 18 configured to crank and / or start an engine 12 of the vehicle 10. In examples, a high voltage electric motor starting device 18, such as the ISG 24, can be considered an electric motor starting device configured to operate at a voltage greater than or equal to 30 volts. 25 In examples, an ISG 24 can be considered an electric motor starting device configured to operate at a voltage greater than or equal to 48 volts. In examples, an ISG 24 can be considered an electric motor starting device configured to operate at a voltage in the range 30 to 30 1000 VAC. In examples, a high voltage electric motor starter device 18 can be considered an electric motor starting device configured to operate at a voltage in the range 60 to 1500 VDC. 35 In examples, the at least one ISG 24 comprises an integrated starter generator 24. For example, the ISG 24 can comprise a belt starter generator and / or a crank integrated starter generator. At block 304, method 300 comprises determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12. 40 In some examples, block 304 can be considered to comprise determining an amount of torque 14 to be provided to facilitate the high voltage electric motor starting device start of the engine 12. In some examples, block 304 can be considered to comprise determining an amount of torque 14 to be provided by at least one ISG 24 and an engine 12, from combustion of fuel, during the high voltage electric motor starting device start of the engine 12. An action occurring during a start of an engine 12 / an engine start can be considered to occur before the end of a start phase of the engine 12. A start phase can be considered to end when the engine 12 is up to a desired speed. For example, the start phase can be considered ended when the engine 12 is up to idle speed. In some examples, the start phase can be considered ended when engine speed and / or torque control is handed over to an engine idle controller or driver torque controller. Determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 can be performed in any suitable way using any suitable method. In some examples, determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 comprises determining torque needed and / or required by one or more systems and / or components involved in and / or during the high voltage electric starting device start of the engine 12. In some examples, determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 comprises determining and / or considering torque requirements of one or more systems involved during the high voltage electric starter starting the engine 12. In some examples, determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 comprises determining and / or monitoring one or more engine parameters. In some examples, determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 comprises determining and / or monitoring engine parameters for example, Engine Speed, Engine Temperature (for example oil sump or engine head temperature), Engine Off Time (for example Duration Engine has not been running) and by calculating / determining total torque required. In examples, engine at its stopped position will have higher torque required to rotate compared to when engine speed is at higher speed or idle speed. In examples, determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine comprises determining Engine Speed Target. In examples, engine Speed Target is the engine speed determined by, for example control system 200, for the engine 12 to achieve to determine end of engine starting phase. Higher the delta (Engine target speed minus current engine speed) higher the torque required. In some examples, method 300 comprises determining what engine rate / engine gradient / engine acceleration is required to achieve Engine speed target. Based on various inputs from different control systems different engine speed accelerations can be determined for engine starting phase. 5 A higher engine speed acceleration will require large torque but for a short time. A relatively lower engine speed acceleration will require less starting torque but for a longer time. In some examples, method 300 comprises determining and / or monitoring current / instantaneous engine speed acceleration which is used as input to reduce or increase the torque required to achieve correct engine speed acceleration. A higher than requested 10 engine speed acceleration will require less torque to achieve required engine speed acceleration. In examples, an estimated torque is referenced from control system memory with current engine speed and engine oil temperature and engine off time as input. Torque value in this reference table / memory is generated during extensive testing during engine development phase to determine mechanical losses, throttle / pumping losses. At block 306, method 300 comprises determining an amount of torque 16 available from at least one ISG 24 of the vehicle 10. In examples, determining an amount of torque 16 available from at least one ISG 24 of the vehicle 10 can be performed in any 0^25 suitable way using any suitable method. In some examples, determining an amount of torque 16 available from at least one ISG 24 of the vehicle 10 comprises determining how much torque can be provided by and / or can be generated by the at least one ISG 24. In some examples, determining an amount of torque 16 available from at least one high voltage electrical motor starting device 18 comprises determining at least one of: a state of health of the at least one ISG 24; a state of health of a high voltage system of the vehicle 10; and input from battery management system of the vehicle 10. 30 In some examples, method 300 comprises determining maximum available motoring torque based on inputs from high voltage electric motor starting device and total electrical power available from electrical storage unit (High Voltage Battery pack). In examples, high voltage electric motor starting device is controlled by its own dedicated controller which constantly monitors several input parameters to output best motoring and generating capability. For example, if the electric motor stators are very hot, 35 this will severely reduce its motoring capability. Also, for example, if the operating electrical voltage is less than optimal operating voltage, torque capability will be reduced. In some examples, electrical storage unit often has a control software to manage and determine health of storage pack and output the best available charging and discharging electrical power. For example, if the battery packs are very hot or very cold, charging 40 and discharging capability will be severely reduced. In this case a low electrical capability will be determined In some examples, inputs are taken from both of these high voltage systems and the safest torque for starting system determined. At block 308, method 300 comprises cranking the engine 12 using the at least one ISG 24. Cranking the engine 12 can be considered attempting to start the engine 12 and / or turning a crankshaft of the engine 12. At block 310, method 300 comprises controlling a throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start of the engine 12 in dependence on the amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 and the amount of torque available from the at least one ISG 24. Consequently, FIG 3 illustrates a method 300 comprising: determining that a high voltage electric motor starting device start of an engine 12 of the vehicle 10 is to be performed; determining an amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12; determining an amount of torque 14 available from at least one high voltage electric motor starting device 18 of the vehicle 10; cranking the engine 12 using the at least one high voltage electric motor starting device 18; and controlling a throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start of the engine 12 in dependence on the amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12 and the amount of torque 16 available from the at least one high voltage electric motor starting device 18. In examples, controlling a throttle valve 20 of the engine 12 at block 310 can be performed in any suitable way using any suitable method. Controlling a throttle value 20 of the engine 12 at block 310 can comprise controlling the throttle valve 20 of the engine 12 to meet a torque requirement / need / demand during the high voltage electric motor starting device start of the engine 12. Controlling a throttle valve 20 of the engine 12 at block 310 can comprise controlling the throttle valve 20 of the engine 12 to reduce and / or control relative pressure in one or more combustion chambers of the engine 12 during the start of the engine 12 / engine start. Relative pressure can be considered pressure inside combustion chamber or intake manifold factored by pressure outside the engine 12 or atmospheric pressure. Accordingly, in examples, relative pressure can be considered the pressure inside the combustion chamber or intake manifold of the engine 12 relative to the pressure outside the engine or atmospheric pressure. For example, a relative pressure of 0.25 represents 25 percent of the pressure outside the engine 12. Controlling a throttle valve 20 of the engine 12 at block 310 can comprise controlling the throttle valve 20 of the engine 12 to control an amount of air in one or more combustion chambers of the engine 12 during the start of the engine 12. Controlling a throttle valve 20 of the engine 12 at block 310 can comprise controlling the throttle valve 20 of the engine 12 to reduce and / or control relative pressure in one or more combustion changes of the engine 12 during the start of the engine 12 while ensuring that a torque demand for the start of the engine 12 is met. This allows, for example, the engine to benefit from low pumping losses in the intake manifold and combustion chamber during compression and exhaust stroke of a four stroke cycle, while ensuring sufficient torque is provided to start the engine. In examples, method 300 comprises determining a difference between the amount of torque 14 to be provided during the high voltage electric motor starting device vehicle start of the engine 12 and the amount of torque 16 available from the at least one high voltage electric motor starting device 18, e.g., ISG 24, wherein controlling the throttle valve 20 comprises controlling the throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start of the engine 12 in dependence on the difference. For example, if it is determined that the amount of torque 14 to be provided is greater than the amount of torque 16 available from the at least one ISG 24 the throttle valve 20 of the engine 18 can be controlled to allow additional torque to be provided by the engine 12, from combustion of fuel, during the engine start. Accordingly, in some examples, method 300 comprises determining that the at least one ISG 24 cannot provide the amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12, wherein controlling the throttle valve 20 of the engine 12 comprises at least partially opening the throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start to provide engine torque during the high voltage electric motor starting device start in dependence on the determination. In examples, the throttle valve 20 of the engine 12 can be intelligently controlled in dependence on the determined difference between the amount of torque 14 to be provided and the amount of torque 16 available during the engine start. For example, the throttle valve 20 can be controlled to provide engine torque to cover a shortfall in torque provision by the at least one ISG 24 during the engine start while reducing and / or minimising the amount of air and / or relative pressure in one or more combustion chambers of the engine 12 during the engine start, to ensure low pumping losses in the engine and provide efficient starting of the engine. Accordingly, in some examples, the throttle valve 20 of the engine 12 is kept as closed as possible during the high voltage electric motor starting device start of the engine, to keep pressure in the intake manifold and combustion chamber low during starting of the engine, to provide efficient starting of the engine. However, in some examples, method 300 comprises determining that the at least one ISG 24 can provide the amount of torque 14 to be provided during the high voltage electric motor starting device start of the engine 12, wherein controlling the throttle valve 20 of the engine comprises closing the throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start. Accordingly, in some examples the at least one ISG 24 is powerful enough to provide the full amount of torque 14 to be provided during the engine start and therefore the throttle valve 20 can be closed during the engine start. A throttle valve 20 can be considered an airpath control actuator of the engine 12 of the vehicle 10. 21 03 25 In some examples, block 310 comprises controlling one or more other airpath control actuators of the engine 12. For example, block 310 can comprise controlling one or more exhaust gas recirculation valves of the engine 12 and / or controlling one or more exhaust flaps of the engine 12. 5 In some examples, at block 310, at least one exhaust gas recirculation (EGR) valve of the engine 12 isopen and the exhaust flaps of the engine 12 are open. Keeping the EGR valve open can help recirculate air within the system to prevent creation of a vacuum which can force oil into the combustion chamber. In some examples, the amount of torque 14 to be provided and / or the amount of torque 16 available from the at least one ISG 24 10 can change / vary during the engine start. The determination at block 304, the determination at block 306 and / or the control at block 310 can be updated and / or repeated during the engine start. 15 The throttle valve 20 of the engine 12 of the vehicle 10 can be controlled in dependence on a change / variation in the amount of torque 14 to be provided and / or the amount of torque 16 available from the at least one ISG 24. For example, if the amount of torque 14 to be provided increases during the engine start, the throttle valve can be opened in dependence on the increase to provide an amount of engine torque from combustion of fuel. 20 For example, if the amount of torque 14 to be provided decreases during the engine start, the throttle valve can be closed in dependence on the decrease to reduce relative pressure in one or more combustion chambers of the engine 12 to allow efficient starting of the engine. 25 In some examples, method 300 comprises determining an engine torque request 22 prior to and / or during the high voltage electric motor starting device start of the engine 12 and controlling the throttle valve 20 of the engine 12 in dependence on the determined engine torque request 22. Determining an engine torque request can be performed in any suitable way using any suitable method. 30 For example, determining an engine torque request can comprise receiving one or more signals comprising information indicative of the engine torque request. The engine torque request can result from a driver of the vehicle 10 and / or a request from one or more systems of the vehicle 10. 35 In examples, controlling the throttle valve 20 of the engine 12 in dependence on a determined engine torque request can be performed in any suitable way using any suitable method. In some examples, the throttle valve 20 of the engine 12 is opened to provide engine torque from combustion of fuel sufficient to 40 meet the engine torque requested. For example, it can be determined that a ISG 24 is capable of providing the torque 14 to be provided during the start of the engine 12 and therefore that the throttle valve 20 can be closed during the start of the engine 12, However, if an engine torque request is received prior to and / or during the high voltage electric motor start device start, the throttle valve 20 can be controlled to open sufficiently to meet the engine torque request. One or more blocks of method 300 can be omitted and / or modified. For example, in some examples, it is known that the at least one ISG 24 can provide all of torque 14 to be provided during the start of the engine 12 and therefore, in some examples, blocks 304 and 306 can be omitted and block 310 can be modified accordingly. In some such examples, as it is known that, in the absence of an engine torque request 22, engine torque is not generally required during the engine start and therefore the throttle valve 20 of the engine 12 can be closed during the engine start. Accordingly, in some examples, there is provided a control system 200 for a vehicle 10, the control system 200 comprising one or more controllers 201, wherein the control system 200 is configured to: determine that a high voltage electric motor starting device start of an engine 12 of the vehicle 10 is to be performed; cranking the engine 12 using at least one high voltage electric motor starting device 18 of the vehicle 10; and closing a throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start of the engine 12 of the vehicle 10. In some examples, closing a throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start of the engine 12 comprises closing a throttle valve 20 of the engine 12 prior to and / or during the high voltage electric motor starting device start of the engine 12 in dependence on the determination that a high voltage electric motor starting device start of an engine 12 of the vehicle 10 is to be performed. Method 300 is advantageous and provides one or more technical benefits. For example, method 300 provides for intelligent control of a throttle valve to allow efficient starting of an engine of a vehicle by reducing relative pressure in one or more combustion chambers of an engine while sufficient torque for starting the engine is provided and / or any engine torque demands are met. For example, method 300 provides a robust method of cranking and starting an engine by ensuring sufficient torque is provided to start the engine. For example, method 300 provides for closed throttle engine starts allowing an engine to be started efficiently. For example, method 300 provides for a quiet engine start. For example, method 300 provides for turbulent intake air into the engine post opening of the throttle providing improved air / fuel mixture. For example, method 300 provides fast oil pressure build up and better lubrication of the engine. For example, method 300 provides controlled hand over to fuelled idle control. For example, method 300 provides for a delay in air path actuation which, for example, can assist pneumatically electrically 5 actuated actuators of the engine to operate better. FIG 4 schematically illustrates an example engine start strategy and / or vehicle control design. In examples, FIG 4 can be considered to illustrate a method 400. The method 400 may be a feedback-driven method. 10 In examples, method 400 can be performed by any suitable means. For example, method 400 can be performed by the control system 200 or FIG 2A and 2B. That is, in examples, the control system 200 described herein comprises and / or provides means for performing method 400. 15 However, any suitable means may be used to perform the method 400. The method 400 may be implemented in hardware and / or software. At block 402 ('Engine start request’), an engine start request is received. LO X 120 At block 404 (“E-Machine start"), it is determined whether a high voltage electric motor starting device start of the engine 12 of the vehicle 10 is to be performed. In some examples, determining that a high voltage electric motor starting device start (e.g., ISG start) of an engine 12 of the vehicle 10 is to be performed comprises receiving one or more inputs, such as one or more signals indicating that a high voltage electric motor starting device start of an engine 12 of the vehicle 10 is to be performed. A high voltage electric motor starting device start (e.g., ISG start) can be a default starting procedure and can be used in absence of any indication that a, for example, ISG start cannot be used. For example, a, for example, ISG start can be used unless at fault flag is received indicating that an ISG start is not possible. One or more inputs can be received from any suitable source(s). For example, one or more inputs can be received from / result 30 from a user of the vehicle 10 and / or from one or more systems of the vehicle 10. In a use case, block 404 comprises determining whether the ISG start is permitted. It may not be permitted in some situations such as a fault relating to the ISG 24. If it is determined that a high voltage electric motor starting device start of the engine 12 is not to be performed, the method 400 proceeds to block 406 and a standard start procedure is followed (see block 440). 35 If, however, at block 404 it is determined that a high voltage electric motor starting device start of the engine 12 is to be performed method 400 proceeds to block 408. Block 408 (“Hybrid start torque-split control”) systematically illustrates a torque-split controller for an e-machine start (e.g., ISG 40 start) of an engine 12 by the high voltage electric motor starting device. A torque-split controller can be considered as controlling an amount of torque to be provided by an ISG 24 and an amount of engine torque from combustion of fuel by the engine 12, to be provided simultaneously during start of the engine. In examples, the torque-split controller 408 is involved whenever a high voltage electric motor starting device start of an engine 12 or vehicle 10 is to be controlled. 5 Block 408 can be considered to represent logic that is configured to determine the torque split for an engine start between a torque provided by an engine 12 from combustion of fuel and the ISG 24 in dependence on various inputs, for example in dependence on various inputs from driver torque controller and high voltage components monitoring system. In the example of FIG. 4, inputs into block 408 are represented by blocks 422, 424, 426 and 428. 10 In the example of FIG. 4, a function of a torque-split controller is to determine a torque split between at least one ISG 24 of a vehicle 10 and an engine 12 of a vehicle 10 and / or provide initial / calibrated values for one or more air path actuators. In some examples, at block 410 (“Determine torque split”) a torque split is determined in real time in dependence on one or more inputs (torque target controller 422, and torque limit monitor 424, described later). Block 410 can be described as a torque split 15 controller. For example, at block 410 degradation of a high voltage system of the vehicle and / or failure of such a system can be anticipated and driver torque demand can be monitored / determined. Block 414 (“Stall monitoring”) of FIG. 4 represents stall monitoring. For example, monitoring can be performed of the delta between _ a requested engine speed gradient and an actual engine speed gradient so that failure recovery can be invoked if needed. The CM20 monitoring may be in dependence on one or more inputs 426, 428. Block 412 (“Primary actuator E-machine”) of the example of FIG. 4 represents at least one ISG 24 of the vehicle 10. In examples, this can be considered a primary actuator in the method 400. Block 412 is connected to the torque split controller 410 meaning that the torque split controller 410 can control the torque of the ISG 24. 0^25 Block 416 (“Secondary actuator - fuel") of the example of FIG. 4 represents the engine 12, in its capacity as an actuator for increasing its own speed via fuel combustion. In the illustrated example, this can be considered a secondary actuator in the method 400. Block 416 is connected to the torque split controller 410, meaning that the torque split controller 410 can control the torque of the engine 12 by controlling air, fuel, and ignition. 30 Block 420 (“Backup actuator pinion”) of the example of FIG. 4 represents a backup actuator, such as a starter motor 26 (FIG. 1B). In examples, a backup actuator can be used in case the at least one ISG 24 and engine 12 fail to start the engine 12 robustly. For example, a stall monitor at block 414 may indicate a failure to detect a robust start, where the stall monitor 414 receives inputs 35 from an engine speed controller 428 and engine speed gradient monitor 426. At block 422 (“Breakaway + PID / gradient limited torque calculation”), the total torque target required from the engine's rotating mechanics and parasitic losses are determined by a torque target controller. The total torque target can be considered as an amount of torque 14 to be provided during the ISG start of the engine 12. In some examples, torque required for a desired engine 40 or vehicle acceleration is determined. The determination is based on inputs from blocks 428 (engine speed controller) and 426 (engine speed gradient monitor) to form a total torque target. The total torque target may comprise a determined breakaway torque (torque required to overcome inertia of the vehicle). The total torque target may further comprise a feedback-driven component, such as a PID gain. This may be summed with the breakaway torque. The feedback-driven component may be gradient-limited, for example via an engine gradient monitor shown at block 426. The total torque target increases in dependence on the proportional (P) and integral (I) engine speed and / or torque error, and optionally the differential (D) error. At block 424 (“E-machine torque limit monitoring"), a torque limit(s) of the ISG 24 is determined. This is an indication of an amount of torque available from the ISG 24. This affects how much of the total torque target can be supplied by the ISG 24. The determination is based on inputs from the high voltage system of the vehicle 10, a battery management system of the vehicle 10, and / or information on the state of health of the ISG 24. The inputs affecting the torque limit may be based on a power availability, state of charge, state of health, ambient temperature, or a combination thereof, for example. At block 426 (“Engine gradient monitoring"), the engine instantaneous speed time gradient is determined by an engine speed gradient monitor 426. This gradient feeds into stall monitoring (block 414), idle handover (block 418), and the torque target controller (block 422), to limit the gradient of the total torque request to ensure smooth starts. At block 428 (“Engine speed target”), an engine speed target is determined by an engine speed controller 428. This target can be a synchronization speed between transmission and engine 12, so that the engine 12 can be smoothly connected to the transmission. The engine speed target is determined and provided for use in the torque split determination. Block 428 may define a speed target controller whose target is fed to the torque controller of block 422 to control the total torque target. The target may also be fed to the handover to idle control (block 418), and the stall monitor (block 414). For example, in the presence of a driver demanded restart or start at a high vehicle speed, transmission and engine synchronization can happen at an engine speed higher than idle. In use cases such as stationary engine starts, the engine speed target may be an idle speed target that is not necessarily for synchronisation with transmission speed. Now that the inputs (422, 424, 426, 428) have been further defined, the torque split controller 410 will be further defined. The torque split determination can comprise a determination of whether the ISG 24 can supply all of the total torque target from block 422, based on the amount of the total torque target and the torque limit from block 424. If the ISG 24 cannot supply all of the total torque target, the torque split controller 410 selects both the ISG 24 (block 412) and the engine 12 (block 416) and determines a split or relative proportion of torque to be supplied by each of them simultaneously during engine start. When zero fuel torque (block 416) is required, the throttle valve 20 may be kept closed throughout the engine start (later-defined block 438). If a contribution of fuel torque from the engine 12 is required, the throttle valve 20 may be opened relative to a target closed position to allow the engine 20 to produce the required contribution, but not fully opened (still block 438). Therefore, an advantage is that the throttle valve 20 is kept as closed as possible, and opened by no more than the minimum amount based on the torque split. In effect, the throttle valve 20 is being controlled in dependence on the torque split from block 410. Therefore, the throttle valve 20 is controlled not only in dependence on the total torque target (block 422), but is also controlled in dependence on the torque limit of the ISG 24 (block 424). The higher the torque limit of the ISG 24 is, the more closed the throttle valve 20 can be for a given total torque target. The lower the torque limit of the ISG 24 is, the more open the throttle valve 20 will have to be for the given total torque target. At block 430 (“Pedal input”), a pedal input from a driver can be determined and indicated to the speed target controller of block 5 428. Accordingly, an engine torque request 22 can result from a pedal input at block 430 as indicated towards block 428. Since block 428 is connected to the torque target controller 422, it can be said that the accelerator pedal input from the driver will affect the total torque target and therefore the torque split. If the resulting increase in total torque target exceeds or further exceeds the torque limit of the ISG 24, the throttle valve 20 may be opened relative to its target closed position. 10 The pedal input from block 430 is also fed to a decision block 432 (“Driver demand detected”), where it is determined if a driver torque demand is detected. If driver torque demand is detected, this is signalled to decision block 434 (“Fuel torque requested”) which determines if a fuel torque to satisfy the driver torque demand is requested. This fuel torque may be additional to the fuel consumed by the engine based on block 410. If a fuel torque to satisfy the driver torque demand is requested (block 434), then a standard start mode is required (later-described block 440). 15 Looking at the right-hand side of FIG. 4, the outputs from blocks 408 and 434 of method 400 are input to block 436 (“Airpath control”). In the illustrated example, block 436 represents air path control modes of the engine 12 during the engine start. If it is determined that the at least one ISG 24 can provide the torque 14 that is to be provided during the engine start, Block 438 (“Close throttle, open EGR, open exhaust flaps”) can be applied. Block 438 can be regarded as a closed throttle start mode. At block 438 the throttle valve 20 is closed during the engine start. If a contribution of fuel torque is required by the torque split 0^25 controller 410, then the throttle valve 20 may be variably / continuously variably controlled but not fully open. In the closed throttle start mode 438, the position of the throttle valve 20 is dependent not only on the total torque target but also on the torque limit of the ISG 24. This enables the throttle valve 20 to be ‘as closed as possible’ based on the requirements of the torque split controller 410. In some examples, at block 438, exhaust gas recirculation valve of the engine 12 is open and the exhaust flaps of the engine 12 are open. 30 At block 440 (“Follow standard start procedure”) a standard start mode is applied. Standard start mode 440 differs from closed throttle start mode 438 in that the throttle valve 20 may be fully open, or at least not variably controlled in dependence on the torque limit 424 of the ISG 24. 35 In the example of FIG. 4, in the standard start mode air path valves of the engine 12 are controlled by a base engine torque model / controller which adjusts, for example, the throttle control 20 to achieve the total torque target. In order to initiate engine rotation, either the starter motor may be used, or the ISG 24 may be used. No torque split logic may be employed, or at least no form of torque control based on the torque limit of the ISG 24. Therefore, the throttle valve 20 is not variably or continuously variably controlled based on the torque limit. The throttle valve 20 may even be kept at a static fully open position. This would however 40 increase pumping losses and forego the advantages of the closed throttle start mode 438. If at any point in method 400 fuel torque is requested by, for example, the driver of the vehicle, method 400 will proceed to block 440 and, in examples will not return to block 438 until next engine start request. This logic is implemented in the decision block 434. 5 When the engine start phase is finished, method 400 proceeds to block 442 (“Normal mode") and the engine 12 can be considered to be started. For example, engine 12 can be in idle mode when the start phase is finished. Block 418 (“Handover to idle control”) of FIG. 4 represents handover to idle control. Block 418 is based on inputs from blocks 426 and 428. 10 Examples of the disclosure provide technical benefits and / or are advantageous. For example, examples of the disclosure provide an engine start strategy that reduces noise, vibration, harshness and energy consumption. As used herein “for” should be considered to also include “configured or arranged to”. For example, “a control system for*’ should 15 be considered to also include “a control system configured or arranged to”. LO X 120 It is to be understood that the or each controller 200 can comprise a control unit or computational device having one or more electronic processors (e.g., a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), etc.), and may comprise a single control unit or computational device, or alternatively different functions of the or each controller 200 may be embodied in, or hosted in, different control units or computational devices. As used herein, the term “controller,” “control unit,” or “computational device” will be understood to include a single controller, control unit, or computational device, and a plurality of controllers, control units, or computational devices collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause the controller 200 to implement the control techniques described herein (including some or all of the functionality required for the method described herein). The set of instructions could be embedded in said one or more electronic processors of the controller 200; or alternatively, the set of instructions could be provided as software to be executed in the controller 200. A first controller or control unit may be implemented in software run on one or more processors. One or more other controllers or control units may be implemented in software run on one or more processors, optionally the same one or more processors as the first controller or control unit. Other arrangements are also useful. 30 In the example illustrated in Figure 2A, the or each controller 200 comprises at least one electronic processor 204 having one or more electrical input(s) 210 for receiving one or more input signal(s), and one or more electrical output(s) 212 for outputting one or more output signal(s). The or each controller 200 further comprises at least one memory device 206 electrically coupled to the at least one electronic processor 204 and having instructions 208 stored therein. The at least one electronic processor 204 is configured to access the at least one memory device 206 and execute the instructions 208 thereon so as to, for example, 35 determine that a high voltage electric motor starting device start of an engine of the vehicle is to be performed; determine an amount of torque to be provided during the high voltage electric motor starting device start of the engine; and determine an amount of torque available from at least one high voltage electric motor starting device of the vehicle. The, or each, electronic processor 204 may comprise any suitable electronic processor (e.g., a microprocessor, a microcontroller, 40 an ASIC, etc.) that is configured to execute electronic instructions. The, or each, electronic memory device 206 may comprise any suitable memory device and may store a variety of data, information, threshold value(s), lookup tables or other data structures, and / or instructions therein or thereon. In an embodiment, the memory device 206 has information and instructions for software, firmware, programs, algorithms, scripts, applications, etc. stored therein or thereon that may govern all or part of the methodology described herein. The processor, or each, electronic processor 204 may access the memory device 206 and execute and / or use that or those instructions and information to carry out or perform some or all of the functionality and methodology describe herein. 5 The at least one memory device 206 may comprise a computer-readable storage medium (e.g. a non-transitory or non-transient storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors / computational devices, including, without limitation: a magnetic storage medium (e.g. floppy diskette); optical storage medium (e.g. CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g. EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such 10 information / instructions. Example controllers 200 have been described comprising at least one electronic processor 204 configured to execute electronic instructions stored within at least one memory device 206, which when executed causes the electronic processor(s) 204 to carry out the method as hereinbefore described. However, it will be appreciated that embodiments of the present invention can be 15 realised in any suitable form of hardware, software or a combination of hardware and software. For example, it is contemplated that the present invention is not limited to being implemented by way of programmable processing devices, and that at least some of, and in some embodiments all of, the functionality and or method steps of the present invention may equally be implemented by way of non-programmable hardware, such as by way of non-programmable ASIC, Boolean logic circuitry, etc. 0^25 It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. The blocks illustrated in the FIG 3 and / or 4 may represent steps in a method and / or sections of code in the computer program 208. The illustration of a particular order to the blocks does not necessarily imply that there is a required or preferred order for the blocks and the order and arrangement of the block may be varied. Furthermore, it may be possible for some steps to be omitted. Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. 30

Claims

1. A control system for a vehicle, the control system comprising one or more controllers, wherein the control system is configured to:5 determine that a high voltage electric motor starting device start of an engine of the vehicle is to be performed;determine an amount of torque to be provided during the high voltage electric motor starting device start of the engine; determine an amount of torque available from at least one high voltage electric motor starting device of the vehicle; cranking the engine using the at least one high voltage electric motor starting device; andcontrolling a throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the10 engine in dependence on the amount of torque to be provided during the high voltage electric motor starting device start of the engine and the amount of torque available from the at least one high voltage electric motor starting device.

2. The control system of claim 1, wherein the control system is configured to determine a difference between the amount of torque to be provided during the high voltage electric motor starting device start of the engine and the amount of torque15 available from the at least one high voltage electric motor starting device, wherein controlling the throttle valve comprises controlling the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the engine in dependence on the difference.LO 3. The control system of claim 2, wherein the control system is configured to determine that the at least one high voltageCXJ20 electric motor starting device can provide the amount of torque to be provided during the high voltage electric motor startingdevice start of the engine, and wherein controlling the throttle valve of the engine comprises closing the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start.

4. The control system of claim 2 or claim 3, wherein the control system is configured to determine that the at least one 25 high voltage electric motor starting device cannot provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine, and wherein controlling the throttle valve of the engine comprises at least partially opening the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start to provide engine torque during the high voltage electric motor starting device start in dependence on the determination.30 5. The control system of any preceding claim, wherein the control system is configured to determine an engine torquerequest prior to and / or during the high voltage electric motor starting device start of the engine and to control the throttle valve of the engine in dependence on the determined engine torque request.

6. The control system of any previous claim, wherein determining an amount of torque to be provided during the high 35 voltage electric motor starting device start of the engine comprises determining at least one engine parameter.

7. The control system of any previous claim, wherein determining an amount of torque available from the at least onehigh voltage electric motor starting device comprises determining at least one of:a state of health of the at least one high voltage electric motor starting device;40 a state of health of a high voltage system of the vehicle; andinput from battery management system of the vehicle.

8. The control system of any previous claim, wherein the at least one high voltage electric motor starting device comprises an integrated starter generator.

9. A vehicle comprising a control system as claimed in at least one of claims 1 to 8 an engine and at least one high voltage electric motor starting device configured to start the engine.

10. A method of cranking an engine of a vehicle, the method comprising:determining that a high voltage electric motor starting device start of an engine of the vehicle is to be performed; determining an amount of torque to be provided during the high voltage electric motor starting device start of the engine;determining an amount of torque available from at least one high voltage electric motor starting device of the vehicle; cranking the engine using the at least one high voltage electric motor starting device; andcontrolling a throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the engine in dependence on the amount of torque to be provided during the high voltage electric motor starting device start of the engine and the amount of torque available from the at least one high voltage electric motor starting device.

11. The method of claim 10, comprising determining a difference between the amount of torque to be provided during the high voltage electric motor starting device start of the engine and the amount of torque available from the at least one high voltage electric motor starting device, wherein controlling the throttle valve comprises controlling the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start of the engine in dependence on the difference.

12. The method of claim 11, comprising determining that the at least one high voltage electric motor starting device can provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine 12, and wherein controlling the throttle valve of the engine comprises closing the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start.

13. The method of claim 11 or claim 12, comprising determining that the at least one high voltage electric motor starting device cannot provide the amount of torque to be provided during the high voltage electric motor starting device start of the engine, and wherein controlling the throttle valve of the engine comprises at least partially opening the throttle valve of the engine prior to and / or during the high voltage electric motor starting device start to provide engine torque during the high voltage electric motor starting device start in dependence on the determination.

14. The method of any of claims 10 to 14, comprising determining an engine torque request prior to and / or during the high voltage electric motor starting device start of the engine and to control the throttle valve of the engine in dependence on the determined engine torque request.

15. Computer software that, when executed, is arranged to perform a method according to at least one of claims 10 to 14.

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