Controlling an active air inlet of a vehicle

Abstract

Aspects and embodiments of the invention relate to a control system (200), a system (3), a vehicle (1), a method (400), and computer readable instructions (208). The method (400) is for controlling an active air inlet (10, 12) of a vehicle (1). The method (400) comprises receiving (402) an airflow demand signal and receiving (404) vehicle speed information. The method (400) further comprises determining (406, 410) an opening amount for the active air inlet (10, 12) in dependence on the airflow demand signal and the vehicle speed information. The method (400) further comprises outputting a control signal (408, 412) to control an actuator (220, 222) of the active air inlet (10, 12) in dependence on the determined opening amount.

Description

[0001] CONTROLLING AN ACTIVE AIR INLET OF A VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to controlling an active air inlet of a vehicle. Aspects of the invention relate to a control system, to a system, to a vehicle, to a method, and to computer readable instructions.

[0004] BACKGROUND

[0005] Vehicles comprise heat exchangers, such as air-air heat exchangers or air-liquid heat exchangers. Some types of heat exchangers receive external airflow generated by movement of the vehicle relative to the air. Some vehicles comprise active vents which can be actuated between an open and a closed position. In the open position of the active vent, airflow can reach the heat exchanger inside the vehicle.

[0006] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

[0007] SUMMARY OF THE INVENTION

[0008] Aspects and embodiments of the invention provide a control system, a system, a vehicle, a method, and computer readable instructions as claimed in the appended claims.

[0009] According to an aspect of the present invention there is provided a control system for controlling an active air inlet of a vehicle, the control system comprising one or more processors collectively configured to:

[0010] receive an airflow demand signal;

[0011] receive vehicle speed information;

[0012] determine an opening amount for the active air inlet in dependence on the airflow demand signal and the vehicle speed information; and

[0013] output a control signal to control an actuator of the active air inlet in dependence on the determined opening amount.

[0014] An advantage is that the active air inlet, which affects airflow around the vehicle, is controlled based on multiple parameters. This allows improved arbitration of airflow through the active air inlet versus airflow around the vehicle.

[0015] The control system comprises one or more controllers collectively comprising at least one electronic processor having an electrical input for receiving an input signal; 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: receive the airflow demand signal and vehicle speed information; determine the opening amount; and output the control signal.

[0016] Optionally, for a given value or range of the airflow demand signal, the control signal is configured to request actuation of the active air inlet in a closing direction from a first open position to a second open position in dependence on the vehicle speed information indicating vehicle speed increasing from a first vehicle speed to a second vehicle speed. For example, this may be the case when the given value or range of the airflow demand signal is greater than a lower threshold. When the airflow demand signal is less than the lower threshold, the control signal may be configured to maintain the active air inlet in a substantially closed position for both the first and second vehicle speeds.An advantage is that a desired airflow is maintained, because as vehicle speed increases the active air inlet does not need to be as open to achieve the same airflow rate. If airflow demand is also low, the active air inlet could even be kept closed.

[0017] Optionally, for the given value or range of the airflow demand signal, the control signal is configured to request actuation of the active air inlet in the closing direction from the second open position to a substantially closed position in dependence on the vehicle speed increasing from the second vehicle speed to a third vehicle speed. For example, this may be the case when the given value or range of the airflow demand signal is greater than the lower threshold and less than an upper threshold. When the airflow demand signal is greater than the upper threshold, the control signal may be configured to maintain the active air inlet in an open position at a highest calibrated vehicle speed.

[0018] An advantage is a desired airflow around the vehicle is maintained, because at high vehicle speeds and medium airflow demands the active air inlet may not need to open.

[0019] Optionally, the control system is configured to:

[0020] determine a fan speed for a fan of the vehicle, the fan fluidly coupled to the active air inlet, in dependence on the airflow demand signal and the vehicle speed information; and

[0021] output a fan control signal to control the fan in dependence on the determined fan speed.

[0022] An advantage is that the fan and the active air inlet are controlled in dependence on multiple same parameters. This allows both the fan and the active air inlet to be co-calibrated, allowing more optimal performance.

[0023] Optionally, for the given value or range of the airflow demand signal, the fan control signal is configured to request a decrease of a speed of the fan from a first fan speed to a second fan speed in dependence on the vehicle speed increasing from the first vehicle speed to the second vehicle speed. For example, this may be the case when the given value or range of the airflow demand signal is greater than a lower threshold. When the airflow demand signal is less than the lower threshold, the fan control signal may be configured to request a substantially zero fan speed for both the first and second vehicle speeds.

[0024] An advantage is improved arbitration between forced and passive airflow, because control transitions from forced airflow towards passive airflow as vehicle speed increases and / or as airflow demand falls.

[0025] Optionally, for the given value or range of the airflow demand signal, the fan control signal is configured to request a decrease of the speed of the fan from the second fan speed to a substantially zero fan speed in dependence on the vehicle speed increasing from the second vehicle speed to the third vehicle speed. For example, this may be the case when the given value or range of the airflow demand signal is greater than the lower threshold and less than the upper threshold. When the airflow demand signal is greater than the upper threshold, the fan control signal may be configured to request a nonzero fan speed at the highest calibrated vehicle speed.

[0026] An advantage is improved arbitration between forced and passive airflow as defined above. The third (high) vehicle speed may allow for the active air inlet to be closed and the fan to be inactive.Optionally, for a given value or range of the vehicle speed information, the control signal is configured to request actuation of the active air inlet in an opening direction in dependence on the airflow demand signal indicating increasing airflow demand. Optionally, for the given value or range of the vehicle speed information, the fan control signal is configured to request an increase of fan speed in dependence on the airflow demand signal indicating increasing airflow demand.

[0027] An advantage is improved arbitration between forced and passive airflow as defined above.

[0028] Optionally, the active air inlet is one of a first active air inlet and a second active air inlet of the vehicle, the first and second active air inlets both fluidly coupled to a same fan passage, and wherein the control system is further configured to:

[0029] determine an opening amount for the other one of the first active air inlet and the second active air inlet, in dependence on the airflow demand signal and the vehicle speed information;

[0030] output a further control signal to control an actuator of the other active air inlet in dependence on the determined opening amount for the other active air inlet.

[0031] An advantage is enabling optimisation of vehicle airflow, because the two air inlets can be controlled independently.

[0032] Optionally, the control signal and the further control signal have a different relationship to the airflow demand signal and vehicle speed information such that for a given combination of the airflow demand signal and vehicle speed information, the control signal and the further control signal are configured to request different opening amounts of the first and second active air inlets.

[0033] An advantage is enabling optimisation of vehicle airflow as described above.

[0034] Optionally, the first and second active air inlets are upper and lower active air inlets.

[0035] An advantage is enabling optimisation of vehicle airflow as described above, because the height of the air inlet on the vehicle affects its relationship with airflow around the vehicle.

[0036] Optionally, for a given value or range of the vehicle speed information, the determined opening amounts for the upper active air inlet and the lower active air inlet each have a different relationship with the airflow demand signal, optionally such that the lower active air inlet opens at a slower rate than the upper active air inlet as airflow demand increases.

[0037] An advantage is enabling optimisation of vehicle airflow as described above.

[0038] Optionally, for a given value or range of the airflow demand signal, the determined opening amounts for the upper active air inlet and the lower active air inlet each have a different relationship with the vehicle speed information, optionally such that the lower active air inlet closes at a faster rate than the upper active air inlet as vehicle speed increases.

[0039] An advantage is enabling optimisation of vehicle airflow as described above.

[0040] According to another aspect of the present invention there is provided a system comprising the control system, and the or each active air inlet, controllable as defined above. Optionally, the system further comprises the fan, controllable by the fan control signal.According to a further aspect of the present invention there is provided a vehicle comprising the system or the control system.

[0041] According to a further aspect of the present invention there is provided a method for controlling an active air inlet of a vehicle, the method comprising:

[0042] receiving an airflow demand signal;

[0043] receiving vehicle speed information;

[0044] determining an opening amount for the active air inlet in dependence on the airflow demand signal and the vehicle speed information; and

[0045] outputting a control signal to control an actuator of the active air inlet in dependence on the determined opening amount.

[0046] According to a further aspect of the present invention there is provided a control system or a method for controlling an active air shutter of a vehicle, the control system comprising one or more processors collectively configured to perform the steps of, or the method comprising:

[0047] receiving vehicle speed information and / or an airflow demand signal;

[0048] determining an opening amount for the active air shutter in dependence on the vehicle speed information and / or airflow demand signal; and

[0049] outputting a control signal to control an actuator of the active air shutter in dependence on the determined opening amount.

[0050] According to a further aspect of the invention there is provided computer readable instructions which, when executed by a computer, are arranged to perform any one or more of the methods described herein. 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.

[0051] 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 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.

[0052] Optionally, the one or more processors as defined earlier, are collectively configured to receive vehicle charging state information from a vehicle state determination module, wherein the determination of the opening amount and / or the fan speed is dependent on the vehicle charging state information.

[0053] Optionally, the vehicle charging state information indicates whether an electrical energy storage means of the vehicle is being charged. Optionally, the vehicle speed information comprises a parking brake signal indicative of the vehicle being parked, and / or the vehicle speed information is indicative of the vehicle being stationary. The vehicle speed information may be received as part of (or inferred from) the vehicle charging state information. For example, if the vehicle charging state information is indicative of an energy storagemeans of the vehicle being charged, then the control system is configured to behave in accordance with the vehicle speed information being indicative of the vehicle being stationary.

[0054] Optionally, the fan speed has a first value in dependence on the vehicle charging state information indicating that the electrical energy storage means of the vehicle is being charged, and a second value greater than the first value in dependence on the vehicle charging state information indicating that the electrical energy storage means of the vehicle is not being charged.

[0055] An advantage is reduced noise while the vehicle is stationary and being charged, due to the absence of background noise.

[0056] Optionally, the vehicle charging state information is indicative of which one of a first and second charging mode is active while vehicle charging is taking place, wherein the first and second charging modes control a charging speed of the vehicle. Optionally, the first charging mode is associated with a higher charging rate than the second charging mode. Optionally, the first and second charging modes comprise a direct current charge mode, and an alternative current charge mode, respectively. Optionally, the fan speed has a greater value in dependence on the vehicle charging state information indicating that the first charging mode is active, compared to the vehicle charging state information indicating that the second charging mode is active.

[0057] BRIEF DESCRIPTION OF THE DRAWINGS

[0058] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0059] FIG. 1A illustrates a perspective view illustrating an example vehicle;

[0060] FIG. 1 B illustrates a side cross-section view illustrating an example airflow apparatus;

[0061] FIG. 2 illustrates a schematic view illustrating an example control system;

[0062] FIG. 3 illustrates a schematic view illustrating an example non-transitory computer-readable storage medium;

[0063] FIG. 4 illustrates a flowchart illustrating an example method;

[0064] FIGS. 5A, 5B, 50 illustrate graphs illustrating example relationships between a fan speed, an upper active air inlet opening amount, and a lower active air inlet opening amount, with an airflow demand signal and vehicle speed; and

[0065] FIG. 6 illustrates a schematic view illustrating an example control system.

[0066] DETAILED DESCRIPTION

[0067] A vehicle 1 in accordance with an embodiment of the present invention is described herein with reference to the accompanying FIG.

[0068] 1A. In some, but not necessarily all examples, the vehicle 1 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.

[0069] The vehicle 1 can comprise any appropriate torque source for delivering tractive torque to vehicle wheels. For example, the vehicle 1 can comprise an electric drive unit. Additionally, or alternatively, the vehicle 1 can comprise an internal combustion engine. The vehicle 1 may be an electric vehicle, a hybrid electric vehicle, an internal combustion engine vehicle, or similar.

[0070] The vehicle 1 comprises, at its front end, a front bumper 66, a bonnet 22 (hood), an underfloor 24, front quarter panels (not shown) (fenders, front wings), wheel arches (not shown), and headlamp clusters (not shown).The front bumper 66 may be a panel covering a front section of the vehicle 1, extending up from a front lip 58, such as a front splitter, to the leading edge 34 of the bonnet 22 and to lower edges of the headlamp clusters. The front bumper 66 may extend laterally to cover substantially the whole frontal width of the vehicle 1 , and may comprise curved corners to extend back to the wheel arches and / or to the front quarter panels.

[0071] It would be appreciated that the above-described panels of the vehicle 1 could be implemented differently. Some panels could be merged and / or omitted.

[0072] In FIG. 1B, the vehicle 1 comprises an internal heat exchanger 18 in the under-bonnet compartment 23 of the vehicle 1 behind the front bumper 66. The heat exchanger 18 is also referred to as a radiator pack. The heat exchanger 18 may comprise an air-to-liquid heat exchanger, configured to transfer heat to airflow passing therethrough. The liquid to be cooled may comprise water and / or coolant.

[0073] If the vehicle 1 is an electric vehicle, the heat exchanger 18 may comprise a radiator configured as part of a cooling system for electric vehicle components such as an electric traction battery and / or an electric traction motor.

[0074] Additionally, or alternatively, the heat exchanger 18 comprises a condenser configured as part of a cabin heating ventilation and cooling system (HVAC system) for maintaining a user’s desired setpoint cabin temperature.

[0075] If the vehicle 1 comprises an internal combustion engine, the heat exchanger 18 may comprise an engine coolant heat exchanger.

[0076] Additionally, or alternatively, the heat exchanger 18 can comprise other types of heat exchangers such as oil coolers, intercoolers, exhaust gas coolers, etc.

[0077] The heat exchanger 18 may be configured as a log-law drag cooling system, wherein heat is conductively transferred from heat exchanger fluid to its fins and pipes which are parallel to airflow. A boundary layer of airflow along the heat exchanger fins and pipes transports heat to the airflow via convective heat transfer. The heated airflow is exhausted at an appropriate location of the vehicle 1.

[0078] As shown in FIG. 1 B, a fan 74 may be provided either upstream or downstream of the heat exchanger 18 to actively draw air through the heat exchanger 18 when natural airflow is insufficient, for example, when the vehicle 1 is stationary.

[0079] In order to control airflow through the heat exchanger 18, an airflow apparatus 2 suitable for use with the heat exchanger 18 is provided within the under-bonnet compartment 23 of the vehicle 1. The airflow apparatus 2 comprises one or more active air inlets 10, 12 aligned with corresponding grille apertures in a central region of the front bumper 66.

[0080] The central region of the front bumper 66 refers to a region laterally between the headlamp clusters, below the leading edge 34 of the bonnet 22, and above the front splitter 58. The active air inlets 10, 12 may optionally have a symmetrical shape about a vehicle longitudinal centreline.

[0081] In the Figures, but not necessarily in all examples, a first active air inlet 10 and a second active air inlet 12 are provided, which are fluidly connected to the same heat exchanger 18. In further examples, only one active air inlet is provided, or more than two active air inlets.In some examples, one of the active air inlets 10 is above the other active air inlet 12, as illustrated. Therefore, the first active air inlet 10 will be described as an upper active air inlet, and the second active air inlet 12 as a lower active air inlet.

[0082] In some, but not necessarily all examples, the upper active air inlet 10 is configured to provide airflow primarily or exclusively to an upper portion of the heat exchanger 18. In some, but not necessarily all examples, the lower active air inlet 12 is configured to provide airflow primarily or exclusively to a lower portion of the same heat exchanger 18.

[0083] In other examples, the upper and lower active air inlets 10, 12 each provide airflow to the whole heat exchanger 18 (airflow not segregated) or to different portions of the heat exchanger 18 from those given above.

[0084] The upper and lower active air inlets 10, 12 may be vertically separated from each other by a lateral bumper member 60. In some examples, the lateral bumper member 60 covers an internal front bumper crash beam. Optionally, the lateral bumper member 60 is configured to support a vehicle licence plate.

[0085] In FIG. 1 B, but not necessarily all examples, the upper active air inlet 10 has a larger frontal area than the lower active air inlet 12.

[0086] Each of the upper and lower active air inlets 10, 12 can be covered by an individual grille 30 mounted to the front bumper 66, an example of which is shown in cross-section in FIG. 1 B. Either the same grille 30 or different grilles 30, 31 may cover the respective upper and lower active air inlets 10, 12. In some examples, the grilles 30, 31 may comprise a honeycomb arrangement of apertures, or may comprise parallel bars or any other suitable arrangement. In some examples, some of the apertures in the grilles 30, 31 are blanked to control airflow, and / or in some examples, airflow may be able to enter the airflow apparatus 2 around a periphery of the grille(s) 30, 31.

[0087] The airflow apparatus 2 may comprise a fan passage 44 (duct) as shown in FIG. 1 B. The fan passage 44 comprises the upper active air inlet 10 and lower active air inlet 12, wherein the upper active air inlet 10 and lower active air inlet 12 are aligned with corresponding grille apertures and grille(s) 30, 31 in the front bumper 66.

[0088] The upper and lower active air inlets 10, 12 may be secured to an interior side of the front bumper 66 and / or the fan passage 44 may be secured to various mounts within the vehicle 1. For example, the upper and lower active air inlets 10, 12 may seal against the interior side of the front bumper 66 via a seal, with or without additional fixings. Airflow may be guided to the heat exchanger 18 by the fan passage 44. The fan passage 44 may be a molded component such as a molded polymeric housing, for example.

[0089] In some examples, the fan passage 44 segregates airflows from the upper active air inlet 10 and from the lower active air inlet 12 and then merges the airflows in a chamber just upstream of the heat exchanger 18. This merging allows the airflows to mix when entering the heat exchanger 18. This arrangement also allows for coordinated use of the active air inlets 10 & 12, opening only one inlet at a time or progressively both in tandem to meet the cooling airflow demand in a calibrated optimal manner.

[0090] If multiple heat exchanger circuits are provided, such as a radiator circuit and a condenser circuit, the airflows from the upper and lower active air inlets 10, 12 reaching each heat exchanger circuit may be segregated. In other examples, the first active air inlet 10 and the second active air inlet 12 are separate and fluidly connected to different heat exchanger circuits.The fan passage 44 also extends downstream of the heat exchanger 18, as the same or a separate connected molded part. After the heat exchanger 18, the airflow may flow along a downstream chamber of the fan passage 44 just downstream of the heat exchanger 18. The airflow then travels to one or more air outlets to be exhausted. For instance, the airflow can travel through downstream duct extensions 45 and exhaust through one or more air outlets 14.

[0091] FIG. 1 B illustrates a first air outlet 14. The first air outlet 14 is configured to exhaust airflow through an aperture 23 in an exterior surface body panel of the vehicle 1 to define a surface air outlet. In some examples, the outlet air can find a "natural" outlet within the engine bay, for example in a wheel arch opening, where the suspension arms are, etc. The exterior surface body panel may be an underbody panel (e.g., underfloor 24 or wheel arch liner) of the vehicle 1, or an upper body panel (e.g., bonnet 22). In some examples, the first air outlet 14 is covered by a grille.

[0092] The upper active air inlet 10 of the airflow apparatus 2 further comprises a variable opening device 20A, configured to be positioned upstream of the heat exchanger 18 to control airflow to the heat exchanger 18. Additionally, or alternatively, the lower active air inlet 10 of the airflow apparatus 2 further comprises a variable opening device 20B, configured to be positioned upstream of the heat exchanger 18 to control airflow to the heat exchanger 18.

[0093] The variable opening devices 20A, 20B are configured to control the upper and lower active air inlets 10, 12 upstream of the heat exchanger 18. The variable opening devices 20A, 20B may each comprise one or more air guiding elements 70 in the form of at least one air valve, air louvre, or any other appropriate air shutter. The variable opening devices 20A, 20B may each comprise an actuator 220, 222 (FIG. 2) to control the air guiding elements 70 of the respective active air inlet 10, 12.

[0094] The actuator 220 of the variable opening device 20A of the upper active air inlet 10 may be a separate actuator 222 from the variable opening device 20B of the lower active air inlet 12. The actuators 220, 222 may be controllable individually.

[0095] When the variable opening device 20A, 20B is in a closed position, the respective active air inlet 10, 12 is at least partially blinded. In some examples, the active air inlet 10, 12 is substantially blinded, but not necessarily fully sealed unless required by the implementation. This configuration is efficient for directing airflow around the outside of the vehicle 1 rather than into the fan passage 44. The proximity of the variable opening devices 20A, 20B to the front end of the vehicle 1 particularly assists with deflecting airflow around the vehicle 1.

[0096] When the variable opening device 20A, 20B is in a fully open position in-service, equal to or less than a hardware-limited maximum possible open position, the respective active air inlet 10, 12 may be open to increase total airflow capacity relative to the closed position. Therefore, opening the second air outlet 16 increases a rate of heat transfer through the heat exchanger 18 by allowing a greater rate of airflow through the heat exchanger 18.

[0097] In some, but not necessarily all examples, one or more of the variable opening devices 20A, 20B can be actuated into one or more selectable intermediate open positions between the fully open position and the closed position. In some examples, there are three or more, or five or more intermediate positions. Intermediate positions enables a controller 201 (FIG. 2) to optimise the balance between cooling performance and deflecting airflow around the vehicle 1.In some examples, the fan speed of the fan 74 can be varied. When ram airflow is low, for example due to low vehicle speed, the fan speed can be increased to increase the mass airflow rate through the heat exchanger 18. When passive ram airflow is high, for example due to high vehicle speed, the fan speed can be decreased while maintaining a desired mass airflow rate through the heat exchanger 18.

[0098] With reference to FIG. 2, there is illustrated a control system 200 for a vehicle 1. The control system 200 comprises one or more controllers 201. For example, the controller 201 may be a Thermal Management controller 201. The control system 200 and the airflow apparatus 2 may collectively define a system 3.

[0099] The control system 200 is configured to receive an airflow demand signal from a demand calculator 214 and receive vehicle speed information from a vehicle speed sensor 216, and in dependence thereof determine an opening amount for the or each active air inlet 10, 12, as well as a fan speed for the fan 74. The control system 200 may then output a control signal to control the or each actuator 220, 222 of the respective active air inlet 10, 12 in dependence on the determined opening amount, and may output a fan control signal to control the fan 74 in dependence on the determined fan speed.

[0100] The demand calculator 214 may comprise a function hosted inside or outside the control system 200, configured to calculate an airflow demand and send an airflow demand signal indicating the airflow demand to the Thermal Management controller 201. The determined airflow demand may be calculated in dependence on one or more inputs such as a temperature setpoint error. The temperature setpoint error may be dependent on a setpoint, and on a sensed temperature. The sensed temperature may be indicative of a fluid temperature in the heat exchanger circuit, or of a cabin air temperature if the heat exchanger 18 is for an HVAC system. The sensed temperature may be received from any appropriate temperature sensor. Optionally, the determined airflow demand may be dependent on other or further inputs.

[0101] The vehicle speed sensor 216 may comprise wheel speed sensors and a vehicle speed calculator, for example. The vehicle speed calculator may determine the vehicle speed in dependence on wheel speeds detected by the wheel speed sensors. Alternatively, a different vehicle speed sensor 216 is used.

[0102] The control system 200 as illustrated in FIG. 2 comprises one controller 201, although it will be appreciated that this is merely illustrative. The controller 201 comprises processing means 204 and memory means 206. The processing means 204 may be one or more electronic processing device 204 which operably execute computer-readable instructions. The memory means 206 may be one or more memory device 206. The memory means 206 is electrically coupled to the processing means 204. The memory means 206 is configured to store instructions, and the processing means 204 is configured to access the memory means 206 and execute the instructions stored thereon.

[0103] The controller 201 comprises an input means 210 and an output means 212. The input means 210 may comprise an electrical input 210 of the controller 201. The output means 212 may comprise an electrical output 212 of the controller 201. The controller 201 may have an interface 202 comprising an electrical input / output I / O 210, 212, or an electrical input 210, or an electrical output 212, for receiving information and interacting with external components. The input 210 is arranged to receive the airflow demand signal from the demand calculator 214, and vehicle speed information from the vehicle speed sensor 216. The signals are electrical signals which are indicative of a required airflow demand, and a vehicle speed of the vehicle 1, respectively. The output 212 is arranged to output an active air inlet control signal, indicative of a required position of the variable opening device 20A, 20B, for controlling the actuator220, 222 of the respective active air inlet 10, 12. The output 212 is also arranged to output a fan control signal, indicative of a required speed of the fan 74, for controlling a motor of the fan 74.

[0104] FIG. 3 illustrates a non-transitory computer-readable storage medium 300 comprising the instructions (computer software).

[0105] FIG. 4 illustrates a method 400 according to an embodiment of the invention. The method 400 is a method of controlling an active air inlet 10, 12 and optionally a fan 74 of a vehicle 1, such as the vehicle 1 illustrated in FIG. 1A, 1B. In particular, but not exclusively, the method 400 is a method of controlling the active air inlets 10, 12 and the fan 74 in dependence on a plurality of common variables 402, 404. The method 400 may be performed by the control system 200 illustrated in FIG. 2. In particular, the memory 206 may comprise computer-readable instructions 208 which, when executed by the processor 204, perform the method 400.

[0106] At block 402, the method 400 comprises receiving an airflow demand signal. The airflow demand signal may be received from the demand calculator 214, as described above. The airflow demand signal may be a variable indicating a zero or more airflow demand. The airflow demand signal may be a variable capable of having a plurality of different nonzero values, such as three or more nonzero values or five or more nonzero values.

[0107] At block 404, the method 400 comprises receiving vehicle speed information. The vehicle speed information may be received from the vehicle speed sensor 216, as described above. The vehicle speed information is a variable indicating a zero or more vehicle speed.

[0108] At block 406, the method 400 comprises determining an opening amount for the upper active air inlet 10 in dependence on both the airflow demand signal of block 402 and the vehicle speed information of block 404. The determination may comprise determining the opening amount from a lookup table or map stored in the memory means 206, or executing a transfer function or algorithm or equivalents thereof.

[0109] Then, at block 408, the method 400 comprises outputting a control signal to control an actuator 220 of the upper active air inlet 10 in dependence on the determined opening amount. The control signal may request an opening amount such as a closed position, a fully open position, or an intermediate position of the one or more air guiding elements 70 of the upper active air inlet 10. In response, the actuator 220 controls the one or more air guiding elements 70 into the requested determining opening amount. An example relationship between the control signal 408 and the inputs 402, 404 is described later in relation to FIG. 5B.

[0110] Concurrently, at block 410, the method 400 comprises determining an opening amount for the lower active air inlet 12 in dependence on both the airflow demand signal of block 402 and the vehicle speed information of block 404. The determination may comprise determining the opening amount from a lookup table or map stored in the memory means 206, or executing a transfer function or algorithm or equivalents thereof.

[0111] Then, at block 412, the method 400 comprises outputting a control signal to control an actuator 222 of the lower active air inlet 12 in dependence on the determined opening amount. The control signal may request an opening amount such as a closed position, a fully open position, or an intermediate position of the one or more air guiding elements 70 of the lower active air inlet 12. In response, the actuator 222 controls the one or more air guiding elements 70 into the requested determining opening amount. An example relationship between the control signal 412 and the inputs 402, 404 is described later in relation to FIG. 5C.The relationship between the inputs 402, 404 and the output signal 412 for the lower active air inlet 12 may be different than the relationships between the inputs 402, 404 and the output signal 408 for the upper active air inlet 10. This allows independent control of the upper and lower active air inlets 10, 12.

[0112] The determined opening amounts for the upper and lower active air inlets 10, 12 may be different for a given pair of values of the airflow demand signal and the vehicle speed information.

[0113] Concurrently, at block 414, the method 400 comprises determining a fan speed for the fan 74 of the vehicle 1 , the fan 74 fluidly coupled to the or each active air inlet 10, 12, in dependence on both the airflow demand signal of block 402 and the vehicle speed information of block 404. The determination may comprise determining the fan speed from a lookup table or map stored in the memory means 206, or executing a transfer function or algorithm or equivalents thereof.

[0114] Then, at block 416, the method 400 comprises outputting a control signal to control a motor of the fan 74 in dependence on the determined fan speed. The control signal may request a zero or more fan speed. In response, the motor of the fan 74 controls the fan 74 to rotate blades of the fan 74 at the requested fan speed. An example relationship between the control signal 416 and the inputs 402, 404 is described later in relation to FIG. 5A.

[0115] Advantageously, the opening amounts of the or each active air inlet 10, 12, and the fan speed of the fan 74, are based on the same variables 402, 404. Therefore, the fan speed is appropriate for the given opening amount of the or each active air inlet 10, 12. Furthermore, the opening amount of the or each active air inlet 10, 12 is appropriate for the given fan speed. The fan speed and inlet opening amounts are coordinated to achieve a balance between heat exchanger performance and airflow around the vehicle 1.

[0116] Furthermore, the relationships between the inputs 402, 404 and the control signals 408, 412, 416 may be based on an offline cocalibration of the inputs and outputs, and / or on an online optimisation function outputting the three control signals 408, 412, 416 in dependence on the inputs 402, 404. This further optimises the fan speed and the determined opening amounts.

[0117] FIGS. 5A-5C graphically indicate examples of how the plurality of active air inlets 10, 12 and the fan 74 may be controlled by the control system 200 and method 400, for different combinations of cooling demand and vehicle speed.

[0118] The x-axis represents increasing airflow demand (‘AD’). In FIG. 5A, the y-axis represents an increasing value of the requested fan speed (‘FS’). In FIG. 5B, the y-axis represents an increasing determined opening amount ‘UAI’ of the upper active air inlet 10. In FIG.

[0119] 5C, the y-axis represents an increasing determined opening amount ‘LAI’ of the lower active air inlet 12.

[0120] The different line types represent increasing vehicle speed 'V, from top left (zero speed, solid line) to the lower right (long dash, highest speed). The graphs of FIGS. 5A-5C have the same normalised scale as each other, and the lines of given dash types represent the same vehicle speeds.

[0121] Table 1 sets out generally the nature of the illustrated relationships between vehicle speed and the outputs, for a given value or range of the airflow demand signal.

[0122]

[0123] Table 1

[0124] Table 2 sets out generally the nature of the illustrated relationships between the airflow demand and the outputs, for a given value or range of the vehicle speed.

[0125]

[0126] Table 2

[0127] Furthermore, FIG. 5A shows that when the airflow demand signal is positive / nonzero and less than a threshold value, the requested fan speed may be approximately zero for most vehicle speeds or regardless of vehicle speed, while at the same time FIG. 5B shows that the upper active air inlet 10 is in an open position dependent on vehicle speed. Therefore, passive airflow is relied upon at low airflow demands. When the airflow demand signal is greater than the threshold value, FIG. 5A shows that the fan speed may increase with increasing airflow demand, the increase being delayed and / or rate limited in dependence on increasing vehicle speed.

[0128] FIG. 5B shows that the determined opening amount of the upper active air inlet 10 is dependent on vehicle speed for most or all values of the airflow demand. Specifically, FIG. 5B shows that the determined opening amount of the upper active air inlet 10 decreases with increasing vehicle speed, for a given above-threshold value or range of the airflow demand signal. For a below-threshold value or range of the airflow demand signal, the upper active air inlet 10 may be in a substantially closed position for at least some vehicle speeds. FIG. 5B also shows that the determined opening amount of the upper active air inlet 10 may increase with increasing airflow demand, the increase being delayed and / or rate limited in dependence on increasing vehicle speed.

[0129] FIG. 5C shows that when the airflow demand signal is positive / nonzero and less than a threshold value, the lower active air inlet 12 may be substantially in its closed position for most vehicle speeds or regardless of vehicle speed, while at the same time FIG. 5B shows that the upper active air inlet 10 is in an open position dependent on vehicle speed. When the airflow demand signal is greater than the threshold value, FIG. 5C shows that the determined opening amount of the lower active air inlet 12 may decrease withincreasing vehicle speed. FIG. 5C also shows that the determined opening amount of the lower active air inlet 12 may increase with increasing airflow demand, the increase being delayed and / or rate limited in dependence on increasing vehicle speed.

[0130] At high airflow demands greater than an upper threshold value, the respective active air inlet 10, 12 may be prevented from fully closing. This is illustrated by the lower-right most long-dashed line in the graphs, representing the highest calibrated vehicle speed.

[0131] An effect of keeping the fan speed zero and / or the lower active air inlet 12 closed for low airflow demands at a wide range of vehicle speeds is that the airflow apparatus 2 relies only on passive airflow through the upper active air inlet 10.

[0132] FIGS. 5B and 5C also show that for a given value or range of the airflow demand signal, the dependency of the determined opening amount of the upper active air inlet 10 on vehicle speed may be different than the dependency of the determined opening amount of the lower active air inlet 12 on vehicle speed.

[0133] An effect of independently controlling opening and closing of the upper and lower active air inlets 10, 12 is to allow the airflow around the vehicle 1 to be optimised relative to heat exchanger performance, based on the aerodynamic characteristics of the vehicle 1 and the inlets 10, 12. The extent of the difference depends on the vehicle body shape and the relative sizes and aerodynamic characteristics of the upper and lower inlets 10, 12.

[0134] As an example, the dependencies may be different such that lower active air inlet 12 closes with increasing vehicle speed at a faster rate than the upper active air inlet 10 closes with increasing vehicle speed, for the given value or range of the airflow demand signal. The lower active air inlet 12 may close with increasing vehicle speed to a lower zero or more percentage opening than the upper active air inlet 10. An effect is that at high vehicle speeds, the upper active air inlet 10 is more open than the lower active air inlet 12, for a given value or range of the airflow demand signal. Note that this example is not limited to all implementations, because it depends on the vehicle body shape and the relative sizes and aerodynamic characteristics of the upper and lower inlets 10, 12.

[0135] Furthermore, for a given value or range of the vehicle speed, the dependency of the determined opening amount of the upper active air inlet 10 on the airflow demand signal may be different than the dependency of the determined opening amount of the lower active air inlet 12 on the airflow demand signal. For example, the lower active air inlet 12 may open at a slower rate than the upper active air inlet 10 as airflow demand increases, for a given value or range of the vehicle speed.

[0136] 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. For example, the principles of independently controlling the two active air inlets fluidly coupled to the same heat exchanger can apply to implementations where at least one of the air inlets is at a location other than the front of the vehicle, or where the inlets are laterally offset from each other.

[0137] It is to be understood that the or each controller 201 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 201 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 201 to implement the control techniques described herein (including some or all of the functionality required for the method(s) described herein). The set of instructions 208 could be embedded in said one or more electronic processors 204 of the controller 201; or alternatively, the set of instructions 208 could be provided as software to be executed in the controller 201. 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.

[0138] The, or each, electronic processor 204 may comprise any suitable electronic processor (e.g., a microprocessor, a microcontroller, an ASIC, etc.) that is configured to execute electronic instructions 208. 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 described herein.

[0139] 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. Examples of the form include, 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 information / instructions.

[0140] It will be appreciated that embodiments of the present invention can be 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 nonprogrammable ASIC, Boolean logic circuitry, etc.

[0141] The blocks illustrated in FIG. 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.

[0142] Features described in the preceding description may be used in combinations other than the combinations explicitly described. Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

[0143] FIG. 6 schematically illustrates an example of the control system 200 further configured to receive vehicle charging state information from a vehicle state determination module 217. For example, the vehicle 1 may be a battery electric vehicle or hybrid electric vehicle comprising an electrical energy storage means 219 (e.g., traction battery) and an electric drive unit (not shown).The vehicle charging state information indicates whether the electrical energy storage means 219 of the vehicle 1 is being charged, for example by a charger external to the vehicle 1. Optionally, the vehicle charging state information further indicates which charging mode is active while the vehicle charging is taking place. For example, the vehicle charging modes may comprise a 'fast charge’ mode and a 'slow charge’ mode, if supported by the vehicle 1. The fast charge mode may comprise a DC (direct current) charge mode. The slow charge mode may comprise an AC (alternating current) charge mode. The DC charge mode is associated with a higher charging rate than the AC charge mode. The vehicle charging modes may be referred to more generically as first and second vehicle charging modes, controlling a charging speed of the vehicle 1.

[0144] The determination by the control system 200 of the fan speed may be dependent on the vehicle charging state information. If the vehicle charging state information indicates that the vehicle 1 is not being charged, the fan speed may be allowed to be higher than when the vehicle 1 is being charged. This is to reduce noise while the vehicle 1 is stationary and being charged, due to the absence of background noise. Furthermore, the fan speed may optionally be allowed to be higher in the DC charge mode than in the AC charge mode, to balance noise against cooling demands.

[0145] While the vehicle 1 is stationary and being charged, the vehicle speed information may be indicative of the vehicle 1 being stationary, and / or comprises a parking brake signal indicative of the vehicle being parked. The vehicle speed information may be received as part of (or inferred from) the vehicle charging state information. For example, if the vehicle charging state information is indicative of an energy storage means 219 of the vehicle 1 being charged, then the control system 200 is configured to behave in accordance with the vehicle speed information being indicative of the vehicle 1 being stationary.

[0146] The dependency of fan speed on vehicle charging state information can be implemented via separate maps setting out different relationships between fan speed and airflow demand, wherein the different maps are selected depending on whether charging is taking place or not. For example, a first map corresponding to FIG. 5A could be selected by the control system 200 when charging is not taking place, and a second map corresponding to a modified version of FIG. 5A could be selected when charging is taking place. The second map of FIG. 5A may have lower fan speeds for a given range of airflow demand, than the first map. Likewise, a DC charging map may vary from an AC charging map.

[0147] Alternatively, or additionally, the determination by the control system 200 of the opening amount of the active air inlet 10 and / or 12, may be dependent on the vehicle charging state information. For example, the active air inlet 10 and / or 12 may be moved in an opening direction in dependence on the vehicle charging state information indicating that the electrical energy storage means 219 is being charged, and in a closing direction in dependence on the vehicle charging state information indicating that the electrical energy storage means 219 is not being charged. The dependence of the opening amount on the vehicle charging state information can be implemented via separate maps, similarly to fan speed. There is also the possibility of opening the active air inlet 10 and / or 12 more during DC charging than AC charging, for example if the fan 74 requires more airflow.

Claims

CLAIMS1. A control system for controlling an active air inlet of a vehicle, the control system comprising one or more processors collectively configured to:receive an airflow demand signal;receive vehicle speed information;determine an opening amount for the active air inlet in dependence on the airflow demand signal and the vehicle speed information; andoutput a control signal to control an actuator of the active air inlet in dependence on the determined opening amount.

2. The control system of claim 1 , configured to:determine a fan speed for a fan of the vehicle, the fan fluidly coupled to the active air inlet, in dependence on the airflow demand signal and the vehicle speed information; andoutput a fan control signal to control the fan in dependence on the determined fan speed.

3. The control system of claim 2, wherein for a given value or range of the airflow demand signal, the control signal is configured to request actuation of the active air inlet in a closing direction from a first open position to a second open position in dependence on the vehicle speed information indicating vehicle speed increasing from a first vehicle speed to a second vehicle speed.

4. The control system of claim 3, wherein for the given value or range of the airflow demand signal, the fan control signal is configured to request a decrease of a speed of the fan from a first fan speed to a second fan speed in dependence on the vehicle speed increasing from the first vehicle speed to the second vehicle speed.

5. The control system of claim 3 or 4, wherein for the given value or range of the airflow demand signal, the control signal is configured to request actuation of the active air inlet in the closing direction from the second open position to a substantially closed position in dependence on the vehicle speed increasing from the second vehicle speed to a third vehicle speed.

6. The control system of claim 5, wherein for the given value or range of the airflow demand signal, the fan control signal is configured to request a decrease of the speed of the fan from the second fan speed to a substantially zero fan speed in dependence on the vehicle speed increasing from the second vehicle speed to the third vehicle speed.

7. The control system of any one of claims 2 to 6, wherein for a given value or range of the vehicle speed information, the control signal is configured to request actuation of the active air inlet in an opening direction in dependence on the airflow demand signal indicating increasing airflow demand.

8. The control system of claim 7, wherein for the given value or range of the vehicle speed information, the fan control signal is configured to request an increase of fan speed in dependence on the airflow demand signal indicating increasing airflow demand.

9. The control system of any one of claims 2 to 8, wherein the one or more processors are collectively configured to receive vehicle charging state information from a vehicle state determination module, wherein the determination of the opening amount and / or the fan speed is dependent on the vehicle charging state information.

10. The control system of any preceding claim, wherein the active air inlet is one of an upper active air inlet and a lower active air inlet of the vehicle, the upper and lower active air inlets both fluidly coupled to a same fan passage, and wherein the control system is further configured to:determine an opening amount for the other one of the upper active air inlet and the lower active air inlet, in dependence on the airflow demand signal and the vehicle speed information;output a further control signal to control an actuator of the other active air inlet in dependence on the determined opening amount for the other active air inlet.

11. The control system of claim 10, wherein for a given value or range of the vehicle speed information, the determined opening amounts for the upper active air inlet and the lower active air inlet each have a different relationship with the airflow demand signal, optionally such that the lower active air inlet opens at a slower rate than the upper active air inlet as airflow demand increases, and / or wherein for a given value or range of the airflow demand signal, the determined opening amounts for the upper active air inlet and the lower active air inlet each have a different relationship with the vehicle speed information, optionally such that the lower active air inlet closes at a faster rate than the upper active air inlet as vehicle speed increases.

12. A system comprising the control system of any one of the preceding claims, and the active air inlet.

13. A vehicle comprising the system of claim 12, or the control system of any one of claims 1 to 11.

14. A method for controlling an active air inlet of a vehicle, the method comprising:receiving an airflow demand signal;receiving vehicle speed information;determining an opening amount for the active air inlet in dependence on the airflow demand signal and the vehicle speed information; andoutputting a control signal to control an actuator of the active air inlet in dependence on the determined opening amount.

15. Computer readable instructions which, when executed by a computer, are arranged to perform a method according to claim 14.

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