Vehicle cabin thermal control system

Abstract

There is disclosed a control system (100) for controlling a climate control system (200) of a vehicle (10), the climate control system comprising a blower (810), the control system comprising one or more processors (120) collectively configured to: receive an external thermal indicator signal (155) indicative of an external ambient temperature sensed by an external ambient temperature sensor (150) of the vehicle; receive a cabin temperature setpoint signal (165) in response to a temperature setpoint input, the cabin temperature setpoint signal indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle; retrieve, in dependence on the desired cabin temperature setpoint and the external ambient temperature, a predetermined mapping relationship (175) mapping a blower speed to an energy error value, the energy error value indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint; determine an blower speed (350) based on the desired cabin temperature setpoint and the retrieved predetermined mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; and output a control signal (195) to the climate control system to cause the blower to operate at the blower speed.

Description

[0001] VEHICLE CABIN THERMAL CONTROL SYSTEM

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a vehicle cabin thermal control system. Aspects of the invention relate to a control system for controlling a climate control system of a vehicle, to a climate control system, a vehicle, a method for controlling a climate control system of a vehicle and to computer readable instructions for performing methods for controlling a climate control system of a vehicle.

[0004] BACKGROUND

[0005] It is known to provide climate control within a vehicle cabin by blowing air, which may be heated or cooled, and / or which may be provided from within the cabin (recirculation air), from outside the cabin (external air) or a mixture of the two. It can be challenging to provide climate control in an energy efficient way, which is particularly important for electric vehicles such as battery electric vehicles where air heating and air cooling are performed using energy drawn from the vehicle battery. Identifying a combination of parameters of a climate control system which can provide a desired climate in an energy efficient way is not straightforward.

[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 for controlling a climate control system of a vehicle, to a climate control system, a vehicle, a method for controlling a climate control system of a vehicle and to computer readable instructions for performing methods for controlling a climate control system of a vehicle, as claimed in the appended claims.

[0009] According to an aspect of the present invention, there is provided a control system for controlling a climate control system of a vehicle, the climate control system comprising a blower, the control system comprising one or more processors collectively configured to: receive an external thermal indicator signal indicative of an external ambient temperature; receive a cabin temperature setpoint signal indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle; retrieve, in dependence on the desired cabin temperature setpoint and the external ambient temperature, a blower speed from a predetermined blower speed mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; and output a control signal to the climate control system to cause the blower to operate at the blower speed. The predetermined blower speed mapping relationship maps possible blower speeds, desired cabin temperature setpoints, and energy input to operate the blower (and in some examples operate a temperature change element such as a heater or cooler), to achieve the desired cabin temperature setpoints for different external ambient temperatures. An energy efficient way of operating the blower can be identified and used to control the climate control system and provide the desired cabin temperature setpoint in an energy efficient, way.

[0010] According to an aspect of the present invention, there is provided a control system for controlling a climate control system of a vehicle, the climate control system comprising a blower, the control system comprising oneor more processors collectively configured to: receive an external thermal indicator signal indicative of an external ambient temperature sensed by an external ambient temperature sensor of the vehicle; receive a cabin temperature setpoint signal in response to a temperature setpoint input, the cabin temperature setpoint signal indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle; retrieve, in dependence on the desired cabin temperature setpoint and the external ambient temperature, a predetermined mapping relationship mapping a blower speed to an energy error value, the energy error value indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint; determine a blower speed based on the desired cabin temperature setpoint and the retrieved predetermined mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; and output a control signal to the climate control system to cause the blower to operate at the blower speed.

[0011] The predetermined mapping relationship maps various blower speeds to energy error values (which may also be called “energy difference values”) which provide an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint, at different external ambient temperatures. Advantageously, by using the predetermined mapping relationship to adjust the blower speed of the climate control system based on the desired cabin temperature setpoint, the cabin temperature of a vehicle can be adjusted to a desired cabin temperature in a manner identified as being particularly energy efficient through comparison of possible blower speeds and energy requirements of each blower speed as per the predetermined mapping relationship. As a result, an energy efficient way of controlling the climate control system is identified using the mapping, and can be used to control the blower.

[0012] The control system may comprise 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 external thermal indicator signal (as an electrical input signal) indicative of the external ambient temperature sensed by the external ambient temperature sensor of the vehicle; receive the cabin temperature setpoint signal (as an electrical input signal) in response to the temperature setpoint input, the cabin temperature setpoint signal indicative of the desired cabin temperature setpoint for the cabin temperature of the vehicle; retrieve, in dependence on the desired cabin temperature setpoint and the external ambient temperature, the predetermined mapping relationship mapping a blower speed to an energy error value, the energy error value indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint; determine a blower speed based on the desired cabin temperature setpoint and the retrieved predetermined mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; and output (e.g. via an electrical output for outputting an output signal) the control signal to the climate control system to cause the blower to operate at the blower speed.

[0013] The temperature setpoint input may comprise a user temperature setpoint input (e.g. according to a user input indicative of a desired cabin temperature) or a climate control system temperature setpoint (e.g. according toa temperature identified for the climate control system to provide e.g. by another vehicle system or by the climate control system).

[0014] The control system may be configured to retrieve the predetermined mapping relationship by selecting the predetermined mapping relationship from a set of predetermined mapping relationships based on a predetermined offset. The predetermined offset may be selected based on a difference between the desired cabin temperature setpoint and a fixed cabin temperature setpoint. For example, a predetermined relationship may be identified by determining an offset from a relationship representative of a fixed cabin temperature setpoint. That is, a default, standard, or starting, relationship may represent energy requirements for blower operation at a temperature of 15°C, and a relationship providing a more energy efficient blower operation to achieve the cabin temperature setpoint may be at a temperature of 22°C, so an offset of 22°C - 15°C = 7°C may be applied to use the more energy efficient relationship to identify a blower operation speed. Advantageously, an applicable predetermined mapping relationship can be selected from the set of predetermined mapping relationships, based on a desired cabin temperature setpoint and a fixed cabin temperature setpoint (i.e. a temperature setpoint taken as a fixed starting point, e.g. at an average comfort temperature, from which other temperature setpoints are some temperature difference away). This allows for adjustment of blower speed across a wider range of desired cabin temperature setpoints by using data stored in a storage-efficient manner, by using the set of predetermined mapping relationships.

[0015] The control system may be configured to select the predetermined mapping relationship corresponding to the climate control system operating using a lower blower speed compared to a climate control system operating according to a remainder of the set of predetermined mapping relationships. This may provide a most energy efficient blower operation. Advantageously, a predetermined mapping relationship is selected which uses a low blower speed to improve energy efficiency whilst maintaining the functionality of efficiently adjusting the cabin temperature towards the desired cabin temperature setpoint.

[0016] The control system may be configured to: receive a cabin temperature signal indicative of a sensed cabin temperature sensed by an internal temperature sensor of the vehicle; and determine the blower speed further based on the sensed cabin temperature to adjust the cabin temperature towards the desired cabin temperature setpoint. Advantageously, the blower speed may also be determined based on the current sensed cabin temperature. This may allow control of the blower speed dependent on a difference between the current actual cabin temperature and the desired cabin temperature. Hence, the blower speed can be adjusted to achieve the desired cabin temperature setpoint in an energy efficient way (e.g. in a way which uses a minimal fan speed / blower power input to achieve the desired cabin temperature).

[0017] The control system may be configured to, in dependence on the cabin temperature signal reaching the desired cabin temperature setpoint, determine a balanced blower speed to maintain the cabin temperature at the desired cabin temperature setpoint. Advantageously, the blower may be controlled to operate at a different blower speed once the cabin temperature reaches the desired cabin temperature setpoint, which may be a lower fan speed / a different blower power mode than that used to achieve the desired cabin temperature setpoint, thereby improving energy efficiency of blower operation.The cabin temperature may be determined to reach the desired cabin temperature setpoint, for example, by determining that a rolling average of the cabin temperature over a predetermined temperature sensor time window is within a predetermined tolerance range of the desired cabin temperature.

[0018] The control system may be configured to determine the blower speed further based on the external thermal indicator signal to adjust the cabin temperature towards the desired cabin temperature setpoint. That is, the external temperature may be used to determine how to control the climate control system based on the external ambient temperature affecting the cabin. Advantageously, the external ambient conditions affecting the cabin temperature, such as hot sunny weather, can be accounted for, and the blower can be controlled to provide air to reach and / or maintain the desired cabin temperature setpoint in accordance with the effect of the external ambient conditions.

[0019] The control system may be configured to determine if the external temperature would have the effect of lowering the cabin temperature, and if the sensed cabin temperature is higher than the desired cabin temperature setpoint. If so, the control system may be configured to output the control signal to the climate control system to cause the blower to operate at a reduced blower speed than a current blower speed. Advantageously, the ambient conditions acting to cool the cabin temperature may be used to cool the cabin by lowering the blower speed. This action takes advantage of the cool ambient conditions to lower the cabin temperature and reduce the power used by the climate control system to use the blower to control the cabin temperature in an energy efficient way. A cooler external temperature can be used to cool the internal air by using a lower blower speed to pass the cool external air into the cabin at low blower speed.

[0020] The control system may be configured to determine if the external temperature would have the effect of increasing the cabin temperature, and if the sensed cabin temperature is lower than the desired cabin temperature setpoint. If so, the control system may be configured to output the control signal to the climate control system to cause the blower to operate at a reduced blower speed than a current blower speed. Advantageously, the ambient conditions acting to heat the cabin temperature may be used to heat the cabin by lowering the blower speed. This action takes advantage of the warm ambient conditions to adjust the cabin temperature and reduce the power used by the climate control system to control the cabin temperature. A warmer external temperature can be used to heat the internal air by using a lower blower speed to pass the heated external air into the cabin at low blower speed.

[0021] The climate control system may comprise a temperature change element (e.g. a heating element). The control system may be configured to: determine an adjusted discharge temperature based on the external ambient temperature and the desired cabin temperature setpoint, the adjusted discharge temperature determined to heat the cabin temperature towards the desired cabin temperature setpoint; and output the control signal to the climate control system to cause the heating element to operate at the adjusted discharge temperature. Advantageously, the climate control system can be further controlled to adjust the air discharge temperature based on the effect of the external ambient temperature on the cabin temperature by using a heating element. If adjusting the blower speed is determined not to be sufficient to achieve the desired cabin temperature (forexample by providing warmer external air into the cabin to warm it), the heating element may also be used to heat the air provided to the cabin. In short, if the blower speed change alone is not sufficient to obtain the desired in cabin air temperature, then the air provided by the blower can be heated as well.

[0022] The climate control system may comprise an air conditioning element. The control system may be configured to: determine an adjusted discharge temperature based on the external ambient temperature and the desired cabin temperature setpoint, the adjusted discharge temperature determined to cool the cabin temperature towards the desired cabin temperature setpoint; and output the control signal to the climate control system to cause the air conditioning element to operate at the adjusted discharge temperature. Advantageously, the climate control system can be further controlled to adjust the air discharge temperature based on the effect of the external ambient temperature on the cabin temperature by using an air conditioning element. If adjusting the blower speed (for example by providing more cooler external air into the cabin to cool it) is determined not to be sufficient to achieve the desired cabin temperature, the air conditioning element may also be used to cool the air provided to the cabin. In short, if the blower speed change alone is not sufficient to obtain the desired in cabin air temperature, then the air provided by the blower can be cooled as well.

[0023] According to an aspect of the invention, there is provided a system comprising any control system as disclosed herein; and a climate control system comprising a blower. The climate control system may further comprise a heating element. The climate control system may further comprise an air conditioning element.

[0024] According to an aspect of the invention, there is provided a vehicle comprising any system disclosed herein or any control system disclosed herein and an external ambient temperature sensor. The vehicle may comprise a user input element configured to receive a temperature setpoint input. The vehicle may comprise an internal temperature sensor. The vehicle may comprise a climate control system comprising a blower; the climate control system may comprise a heating element and / or an air conditioning element.

[0025] According to an aspect of the invention, there is provided a method for controlling a climate control system of a vehicle, the method comprising: receiving an external thermal indicator signal indicative of an external ambient temperature sensed by an external ambient temperature sensor of the vehicle; receiving a cabin temperature setpoint signal in response to a temperature setpoint input, the cabin temperature setpoint signal indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle; retrieving, in dependence on the desired cabin temperature setpoint and the external ambient temperature, a predetermined mapping relationship mapping a blower speed to an energy error value, the energy error value indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint; determining an blower speed based on the desired cabin temperature setpoint, and the predetermined mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; and outputting a control signal to the climate control system to cause the blower to operate at the blower speed. The retrieved predetermined mapping relationship may be selected by the control system from a set of predetermined mapping relationships based on a predetermined offset. The predetermined offset may be selected based on the difference between the desired cabin temperature setpoint and a fixed cabin temperature setpoint. The retrieved predetermined mapping relationship may correspond to the climate controlsystem operating using a lower blower speed compared to a climate control system operating according to a remainder of the set of predetermined mapping relationships.

[0026] According to an aspect of the invention, there are provided computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform any method disclosed herein.

[0027] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in anyway and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0030] Figure 1 shows a vehicle in accordance with an embodiment of the invention;

[0031] Figure 2 shows a control system in accordance with an embodiment of the invention;

[0032] Figure 3 shows a method which the control system may be configured to perform in accordance with an embodiment of the invention;

[0033] Figure 4 illustrates a series of constant power curves at different ambient temperatures for use in understanding use of the predetermined mapping relationship of Figures 5A-5C;

[0034] Figures 5Ato 5C illustrate predetermined mapping relationships in accordance with embodiments of the invention;

[0035] Figure 6 illustrates a method which the control system may be configured to perform in accordance with an embodiment of the invention; and

[0036] Figure 7 illustrates a system comprising the control system discussed above and a climate control system in accordance with an embodiment of the invention.

[0037] DETAILED DESCRIPTION

[0038] Usually, in a vehicle climate control system, when the climate control system (e.g. an automatic temperature controller (ATC)) sets an airflow level to be delivered to a cabin, to provide a requested cabin thermal comfort level I climate to the occupant(s), the system uses an increased airflow to drive the cabin towards the temperature setpoint and achieve the requested cabin thermal comfort level. This may be irrespective of the external conditions of the vehicle. Also usually, the system uses an airflow setting appropriate to a “midpoint setting” (the midpoint being an energy minimum in a relationship of energy expended in blower operation to achieve a particular temperature setpoint). This midpoint may not be the ideal setting if the system is instructed to run warmer or coolerthan the midpoint and is not the most energy efficient way to operate the climate control system.Operation of the ATC controller of a climate control system may be improved taking account of the external temperature as well as the thermal comfort setpoint to determine the correct blower level to deliver the required customer experience. Examples disclosed herein account for these thermal comfort setpoint and external temperature factors to more energy-efficiently operate the blower of the climate control system.

[0039] A vehicle 10 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1. The vehicle comprises a climate control system, such as the system 700 of Figure 7, and a control system, such as that of Figure 2. The vehicle 10 comprises an external ambient temperature sensor 150 (which need not be located as shown in Figure 1 but may be in any location of the vehicle suitable for detecting the external ambient temperature). The vehicle may be an internal combustion engine vehicle, hydrogen fuel cell vehicle, hybrid vehicle, or electric vehicle. For a hybrid or electric vehicle, energy used to power a climate control system is drawn from the vehicle energy store, so efficient use of energy is especially important in such vehicles but is beneficial in any vehicle. Furthermore, in a battery operated vehicle, any heating to be provided by the climate control system is most frequently generated by a heating element (e.g. a heat pump element and / or resistive heating element) which is powered by the energy store of the battery electric vehicle, as opposed to an internal combustion vehicle in which heat is generated as a byproduct of the engine operation and which may be used for climate control heating. This is another consideration in providing more energy efficient climate control in hybrid or electric vehicles.

[0040] With reference to Figure 2, there is illustrated a control system 100 fora climate control system 200 of a vehicle 10. The control system 100 comprises one or more controller 110. The control system 100 as illustrated in Figure 2 comprises one controller 110, although it will be appreciated that this is merely illustrative. The controller 110 comprises processing means 120 and memory means 130. The processing means 120 may be one or more electronic processing device 120 which operably executes computer-readable instructions. The memory means 130 may be one or more memory device 130. The memory means 130 is electrically coupled to the processing means 120. The memory means 130 is configured to store instructions, and the processing means 120 is configured to access the memory means 130 and execute the instructions stored thereon.

[0041] The control system 100 is configured to receive an external thermal indicator signal 155 indicative of an external temperature from an external temperature sensor 150, and receive a cabin temperature setpoint signal 165 in response to a temperature setpoint input, the cabin temperature setpoint signal 165 being indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle. The control system is configured to retrieve a predetermined mapping relationship 175 mapping a blower speed to an energy error value in dependence on the desired cabin temperature setpoint and the external temperature. The predetermined mapping relationship 175 maps a blower speed to an energy error value. The energy error value is indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint. This is explained in more detail with reference to Figures 5A-5C. The control system 100 is then configured to determine an blower speed, based on the desired cabin temperature setpoint and the retrieved predetermined mapping relationship 175, to adjust the cabin temperature towardsthe desired cabin temperature setpoint. The control system 100 may then output a control signal 195 to the climate control system 200 to cause the blower to operate at the blower speed.

[0042] The controller 110 comprises an input means 140 and an output means 190. The input means 140 may comprise an electrical input 140 of the controller 110. The output means 190 may comprise an electrical output 190 of the controller 110. The input 140 may be arranged to receive the external thermal indicator signal 155 and the cabin temperature setpoint signal 165 in response to a temperature setpoint input. The output 190 may be arranged to output a control signal 195 to the climate control system 200 to cause the blowerto operate at the blower speed.

[0043] The predetermined mapping relationship 175 may be retrieved from the controller memory 130, or another memory means 170 connected to the controller 110. The predetermined mapping relationship 175 maps various blower speeds to energy error values which provide an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint, at different setpoints. Examples are shown in Figures 5A-5C. Advantageously, by using the predetermined mapping relationship 175 to adjust the blower speed of the climate control system based on the desired cabin temperature setpoint, the cabin temperature of a vehicle can be adjusted to a desired cabin temperature in a manner identified as being particularly energy efficient through comparison of possible blower speeds and energy requirements of each blower speed as per the predetermined mapping relationship. As a result, an energy efficient way of controlling the climate control system blower is identified using the mapping, and can be used to control the blower.

[0044] In some examples, the control system 100 may be configured to receive a cabin temperature signal 185 indicative of a sensed cabin temperature sensed by an internal temperature sensor 180 of the vehicle, and determine the blower speed further based on the cabin temperature, to adjust the cabin temperature towards the desired cabin temperature setpoint.

[0045] The predetermined mapping relationship 175 may indicate a blower power level, such as those shown in Figures 5A to 5C, and these relationships may be derived by considering how to deliver the power needed to achieve a particular (for e.g. 22°C) temperature setpoint. That is, the relationships indicate how a particular power can be delivered to achieve a particular temperature setpoint. When the requested cabin temperature can be achieved using a different power, away from the power for delivering the midpoint 22°C temperature setpoint, then a different predetermined blower relationship curve appropriate to that power can be identified by assuming a different ambient temperature.

[0046] This selection of a different blower power level / fan speed which is more appropriate to meet the power delivery request is advantageous over the traditional approach, as blower levels are not traditionally selected in this way. Therefore, traditional climate control systems will not reduce the blower in response to a temperature setpoint change. They will instead change the air discharge temperature only, and provided the system is capable of achieving the new target, the blower will return to the same minimum blower as it would if the temperature setpoint had remained at 22°C. However, by implication, the balance between the blower power and discharge temperature is unlikely to be the most energy efficient way to operate the climate control system.Also, if the climate control system does not achieve the target temperature when the setpoint is away from 22°C, then the blower power usage will be higher, due to moving away from the minimum of the relationship curve 510 (of Figure 5A) (at 0 on the horizontal axis) and away from the midpoint to deliver the different temperature request. It should be noted that in the examples discussed here, 22°C is considered as a default, or central temperature setpoint, however, it could be different, depending on the settings of each vehicle or the climate control system.

[0047] Figure 3 shows a method 300 for controlling a climate control system 200 of a vehicle 10 which the control system 100 may be configured to perform in accordance with embodiments of the invention. The method 300 may be performed by computer readable instructions which, when executed by one or more processors 120, cause the one or more processors to perform the method 300.

[0048] The method 300 comprises receiving at step 302, an external thermal indicator signal 155 indicative of an external temperature sensed by an external temperature sensor of the vehicle. The method 300 further comprises receiving at step 304, a cabin temperature setpoint signal 165 in response to a temperature setpoint input. The cabin temperature setpoint signal 165 is indicative of a desired cabin temperature setpoint for a cabin of the vehicle. Steps 302 and 304 may be performed in any order, or simultaneously.

[0049] Further, the method 300 comprises retrieving at step 310, in dependence on the desired cabin temperature setpoint and the external temperature, a predetermined mapping relationship 175 mapping a blower speed to an energy error value. The predetermined mapping relationship 175 may be retrieved from a storage 130 of the control system 100 performing the method, or another storage 170 in communication with the control system 100. The energy error value is indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint.

[0050] The method 300 comprises determining at step 312 a blower speed 350 based on the desired cabin temperature setpoint, and the predetermined mapping relationship, to adjust the cabin temperature towards the desired cabin temperature setpoint. The method 300 then comprises outputting 314 a control signal 195 to the climate control system 200, to cause the blower to operate at the blower speed 350.

[0051] In some examples, the method 300 may comprise a step 306 of receiving a cabin temperature signal 185 indicative of a cabin temperature sensed by an internal temperature sensor 180 of the vehicle, and determining the blower speed 350 further based on the cabin temperature. The blower speed 350 may be used to use to adjust the cabin temperature towards the desired cabin temperature setpoint. Advantageously, the blower speed to use is also determined based on the current sensed cabin temperature. This may allow control of the blower speed dependent on a difference between the current actual cabin temperature and the desired cabin temperature.

[0052] Figure 4 illustrates a series of constant power curves 400 at different ambient temperatures for delivery of a 26 °C cabin temperature by a climate control system. Blower airflow level as a percentage of maximum blower airflow is plotted on the horizontal axis. Climate control system air discharge temperature in °C is plotted onthe vertical axis. These curves provide a background for understanding the predetermined mapping relationships of Figures 5A-5C. There is a dynamic balance between the environment and the cabin temperatures. Airflow delivered into the vehicle cabin will need to be at a temperature which is offset from the cabin temperature in order to change the cabin air temperature. In order to reduce the blower speed (and therefore expend less energy) to provide a desired cabin air temperature, the temperature of the air delivered into the cabin by the blower needs to be at a different temperature than the external air temperature.

[0053] The curves represent power required at different ambient temperatures outside the vehicle to provide a desired cabin temperature (in this example, 26°C): -30°C (curve 402); -15°C (curve 404); 0°C (curve 406); 10°C (curve 408); 15°C (curve 410); 20°C (curve 412); 30°C (curve 414); and 45°C (curve 416). For example, the curve 410 for an external temperature of 15°C shows that, no matter what the blower speed / % is, the difference in discharge temperature is zero and a cabin temperature of 26°C is achieved. That is, curve 410 does not substantially vary in the vertical direction, as blower speed / % increases and / or decreases. For other external temperatures, some power transfer is required to achieve the 26°C setpoint, and the larger the temperature difference, the larger the power required. As shown in Figure 4, as the blower speed tends to 0%, then the discharge temperature (on the vertical axis) to reach a desired cabin temperature (in this example, 26°C) tends to infinity (in positive and negative directions on the vertical axis). That is, the lower the blower speed / % is, the more a discharge temperature of the climate control system must be changed to deliver the desired cabin temperature of 26°C. It is desirable to have a constant power transfer / exchange which can be achieved by selecting a blower speed / % and an air temperature allowing for constant power transfer (and sit on one of the curves shown in Figure 4).

[0054] A theoretical ‘ideal’ calibration would deliver the same power into the cabin to provide a dynamic balance of energy transfer between the external environment and the cabin. The example of Figure 4 is a theoretical representation to represent realistic values. Note that for a 45°C ambient temperature, per curve 416, the required vent temperature (on the vertical axis) is below 5°C for airflow levels (on the horizontal axis) below about 45%. This is in agreement with practical examples. Also, in practice, the ‘balanced’ tune might be around 60% air flow, such that the discharge target temperature is around 10°C. If a lower airflow than 60% is chosen then the blower intensity would not be sufficient to maintain the desired cabin temperature (26 °C for Figure 4), which again, matches with practical examples. Similarly, if we consider the -30°C ambient temperature curve 402, we see that the vent temperature is greater than 80°C for airflow less than around 23%. From Figure 4, it should be understood that the magnitude of the energy transfer between the air from the blower and the cabin air may be indicated by the curvature of the illustrated curves.

[0055] These curves are determined using a “dark calibration” i.e. there are no solar heating effects to consider. The term “dark calibration” may be understood to relate to the process of finding a dynamic thermal equilibrium of the vehicle, while in dark conditions. Obtaining the dark calibration stability points (i.e. points, not shown, which sit on the curves shown in Figure 4), is performed by trying to maintain a target temperature setpoint of 26°C while varying the blower airflow level as widely as possible at each of the different tested external temperatures respectively giving each of the illustrated curves. The stability points correspond to points on thecurves where a target temperature setpoint of 26 C is maintained for a specific, and stable, blower airflow level.

[0056] Note as an aside in relation to temperature perception, that a target cabin temperature setpoint of 22°C (which may also be called a T-Set of 22°C and is a temperature desired by a user, e.g. as set using a dial in the vehicle; 22°C is chosen as a default, or central, temperature setpoint) may actually correspond to a target cabin air temperature of between 23°C to 30°C, depending on the external ambient temperature (26°C is the temperature setpoint used in this Figure 4 example). For example, at an external ambient temperature of 15°C, to maintain the T-Set of 22°C selected by the user, the cabin air temperature may actually be 26°C, while the blower level may be set to a minimal value, giving a perception of a temperature of 22°C to a vehicle occupant. In another example, in which the external ambient temperature / ”balance point” is colder than (i.e. less than) 15°C, the cabin air temperature may be set to 30°C to provide a perceived desired target temperature setpoint of 22°C; this cabin temperature is higher than the requested 22°C but provides a perception of a cabin temperature of 22°C by countering the thermal effects of a vehicle occupant radiating heat to cold glass of the vehicle. In another example, in which the external ambient temperature is hotter than (i.e. greater than) 15°C, the cabin air temperature / ”balance point” may be set to 23°C to provide a perceived cabin temperature of 22°C to counter the thermal effects of a vehicle occupant receiving radiating heat from the hot glass of the vehicle. In this way, it should be understood that the “balance point” temperature may vary depending on the external ambient temperature. Further variability of the balance point temperature may result based on the determination of the cabin air temperature. For example, the cabin air may be received through one or more vents of the climate control system 100, through which the blower air is delivered to the cabin. The cabin air temperature may be determined based on a weighted average at the one or more vents (e.g. a face vent, configured to provide air in the direction of a user’s face, and / or a foot vent, configured to provide air in the direction of a user’s feet). Thus where in some examples a 15°C “balance point” temperature is provided as an example, in other examples, the “balance point” temperature may be 14°C, 16°C, 13°C, 17°C, or another temperature.

[0057] Thus the example in Figure 4 is a family of curves obtained fora 26°C desired cabin temperature. If the target temperature setpoint I user desired temperature is changed away from 22°C, this will result in a change to the dynamic equilibrium power requirement. If a colder target temperature setpoint is selected (e.g. 21 °C (one degree lower)), then ‘more cold’ may be required in a hot environment and ‘less hot’ may be required in a cold environment. This may be represented in a constant power curve figures as in Figure 4 by, for example, simply applying an offset to the entire Y-axis of the curve set so that the target temperature moves away from 26°C cabin to, for example, 24°C cabin (note that in practice target temperature setpoints and cabin temperatures may not necessarily map in a 1 :1 linear way). This also means that the ‘balance point’ occurs at a lower ambient temperature than the 15°C that applies for the target temperature setpoint of 22°C. In other words, the point where ‘providing more cold air’ (if cooler air is being provided) and ‘providing less hot air’ (if warmer air is being provided) meet, occurs at a colder ambient temperature for a target temperature setpoint of 21 °C. Since moving the balance point to achieve a target temperature setpoint of 21 °C also implies a shift to all the other curves too, a family of curves for a target temperature setpoint of 21 °C may be imagined where the flat curve 410 has moved to, for example, 24°C discharge temperature, and all the curves now apply to lowerambient temperatures by, for example, 3 C (again, there may not necessarily be a 1 :1 trade-off between ambient and cabin temperatures). The same relationship as in Figure 4 may be envisaged, but wherein the Y-Axis is moved by -3°C and the curves now indicate ambient temperatures of -33°C (curve 402), -18°C (curve 404), -3°C (curve 406), 12°C (curve 410)... etc.

[0058] To take advantage of this change in power requirement for minimum energy consumption, the proposed control systems disclosed herein allow the selection of a more appropriate blower level / speed depending on the target temperature setpoint. This means that the control system may be configured to determine an offset that is applied to the ambient temperature that is fed to the blower level I discharge temperature relationships of Figure 4 to achieve a desired cabin temperature. In the example discussed above, for a target temperature setpoint of 21 °C, an offset of 3°C would be applied to the ambient temperature that is used to set the airflow level.

[0059] The size of the offset to select the most effective airflow level may be tuned effectively through experimental investigation of the power curve family during dark calibration. In practice, the curve family may be investigated for a target temperature setpoint of 22°C as well as at different T-Sets up to around 25°C and down to around 19°C, to establish how the curve family varies and to extrapolate between curves for different target temperature setpoints. This in turn may inform the correct offset level to apply to the ambient temperature so that a most energy efficient blower level is selected.

[0060] Figures 5A to 5C illustrate predetermined mapping relationships in accordance with embodiments of the invention.

[0061] Figure 5A illustrates a front airflow request relationship 510 (which may be called a “bathtub” curve or “blower bathtub” curve) plotting the energy error from the setpoint 502 in Joules on the horizontal axis against blower / airflow level 504 as a percentage (%) on the vertical axis for an ambient temperature of 15°C. The front airflow request is a request, for example following a user input, for air to be provided in the cabin at a particular temperature. The curve 510 may be thought of as an indication of energy difference 502 between the ideal operating condition at the curve minimum at 0J and 35% blower speed, and operation away from that minimum point which uses more energy than sitting at the minimum. The minimum of the curve 510 may be understood to sit at a point on a constant power curve as in Figure 4 for a 15°C ambient temperature (i.e. curve 410). Moving horizontally on the curve of Figure 5 which acts to increase the magnitude of energy error, or energy input being made, is equivalent to moving vertically in the plot of Figure 4 to change the blower air temperature (since changing the air blower temperature to move up ordown in blower temperature in Figure 4 uses energy per the horizontal axis of Figure 5A).

[0062] Figure 5B illustrates the front airflow request relationship 510 (which again may be called a series of “bathtub” curves or “blower bathtub” curves) plotting the energy error from the setpoint 502 in Joules on the horizontal axis against blower / airflow level 504 as a percentage on the vertical axis for a series of different ambient temperatures of-40°C (curve 522); -12°C (curve 524); -5 (curve 526); 5°C (curve 528); 15°C (curve 530); 25°C (curve 532); 35°C (curve 534); and 50°C (curve 536).Figure 5C illustrates the minimum blower power / fan speed with ambient (external) temperature relationship 540. Figure 5C is a plot of the ambient temperature 512 in °C on the horizontal axis against the blower airflow provided 514 as a percentage of maximum blower airflow provided to achieve the minimum in the plot of front airflow request against energy error (i.e. at zero energy error). The data in Figure 5C is obtained by looking at the point at which each curve in Figure 5B crosses the vertical axis at zero energy error (at the bottom I minimum of each curve in Figure 5B) and plotting that airflow percentage against the ambient temperature to which it corresponds. From Figure 5C, it can be seen that the minimum in the obtained data is at an ambient temperature of 15°C, which is why the cabin temperature of 15°C (which corresponds to a target temperature setpoint of 22°C) may be considered to be the start, or default temperature, from which the blower airflow may be selected.

[0063] Usually, the airflow to be provided by a blower to achieve a requested cabin temperature may be determined using a blower curve for a cabin temperature of 15°C (i.e. target temperature setpoint of 22°C) because this, at zero energy error, uses a minimum blower airflow of around 35%, as shown at point 550 in Figure 5C. The minimum blower airflow and energy error 502 occurs where the equilibrium power is zero (i.e. at 0 on the horizontal axis), as illustrated in Figure 5B. 15°C is approximately where the zero power balance is for a midpoint temperature setpoint of 22°C. This occurs because the required air delivery temperature to preserve a stable equilibrium cabin temperature is equal to the cabin temperature so the power transfer is minimal. If the setpoint is warmer, then the zero power balance will occur at a higher ambient temperature, and if the setpoint is colder, then the zero power balance will occur at a lower ambient temperature.

[0064] By considering the other curves at different ambient temperatures of Figure 5B, in various scenarios, there may be a lower energy path towards providing the requested cabin temperature. Selecting the ‘most appropriate’ blower level for balanced comfort (i.e. the cabin temperature matches the desired cabin temperature setpoint) and therefore the rest of the energy behaviour that comes with operating the blower at that blower level, according to the predetermined relationship as in Figures 5A and 5B, may allow the delivery of a more energy efficient solution to providing climate control using the blower. This is because, when the blower level is not sufficiently high, the air discharge temperature to achieve the desired air temperature becomes more extreme (e.g. hotter or colder than the cabin), making a thermal system (e.g. a heating element and / or an air conditioning element) work harder. Where the blower level would otherwise be too large, the requirement on the thermal system can be reduced by taking advantage of the external environment (allowing in cold air or hot air from outside the vehicle, where appropriate).

[0065] In general, the ATC (climate control system) airflow (i.e. from the blower level) is controlled by the relationship curves shown in Figures 5A and 5B. For example, in known ATC controllers, the blower level to be used may be selected in dependence on the sensed ambient temperature. A plurality of different relationship curves can be accessed for different ambient temperatures and an interpolation between them can be performed to generate data for a point matching the actual external temperature. As shown in Figure 5C, the lowest blower airflow level, corresponding to point 550, can be used when the external temperature is 15°C. In this case, the amount of energy the climate control system uses to maintain the midpoint comfort setting is at a minimum.However, in existing ATC controllers, the blower level is unchanged for different setpoints (requested cabin temperatures), so that if the occupant chooses a warmer or cooler setpoint than the midpoint, the same blower level is still used and air heating or cooling is performed. Starting from an external temperature of 15°C, if a warmer or cooler setpoint is selected, it can be seen that a higher blower would be needed for the setpoint to be reached without relying on heating e.g. by a heating element, since the 15°C ambient temperature curve has a minimum blower for the midpoint. This also implies that a cooler (i.e. a lower) temperature request setpoint could be achieved using a minimum blower in a lower ambient temperature, since the cooler ambient temperature may act to cool the provided air to the cabin. Similarly, a warmer (i.e. higher) temperature request setpoint could be achieved using a minimum blower in a warmer ambient environment, since the warmer ambient temperature may act to warm the provided air to the cabin.

[0066] Examples disclosed herein provide advantageous energy efficiencies in providing climate control airflow in a vehicle. By selecting the relationship curves for a different ambient temperature than the 15°C ambient temperature curve, the requested cabin temperature may still be achieved while using less energy than operating the climate control system according to the 15°C ambient relationship curve.

[0067] As an example, at an external ambient temperature of 15°C, the minimum power transfer may occur at a target temperature setpoint of 22°C, as indicated by curve 410 and, as such, the blower level may be set at a lowest setting. If a user changes the target temperature setpoint, from Figure 4, the target temperature setpoint may be achieved by increasing the blower level. The selected blower level may be determined using the constant power curves 402-416. For example, from curve 402, it may be considered impractical to use a blower level lowerthan ~35%, due to the required discharge temperature being high. As another example, from curve 416, it may be considered impractical to use a blower level lower than ~55%, due to the required discharge temperature being low. Therefore, the appropriate midpoint blower level for each given power level may be an approximately U-shaped curve, lying on its side in this diagram (e.g. as if using a curve to join a point at 35% on curve 402, a point at 0% on curve 410, and a point at 55% on curve 416). Such a curve may be comparable to curve 540, seen in Figure 5C (i.e. if curve 540 was appropriately transposed and superimposed on to Figure 4). In some examples, ~35% for curve 402, and ~55% for curve 416 may represent minimum practicable values forthe selected blower level and, as such, the midpoint may be a value above the minimum practicable values. In some examples, the midpoint value(s) may be a set percentage above the minimum practicable values (e.g. 15-20%). The midpoint value(s) may depend on the type of vehicle to which the climate control system 100 belongs. For example, for an internal combustion engine vehicle, due to heat energy being a by product of the operation of the internal combustion engine, a high vent temperature may be practicably achieved (e.g. it may be practicable to achieve, for curve 402, a minimum value of 28% blower level at a temperature of 70°C). From this, it should be understood that if the user changes the setpoint away from the midpoint then the blower level setting may move along the U-shaped curve / curve 540 to provide the most appropriate blower level for that power delivery. Since the curve is defined forthe midpoint, in order to move along the curve and find a new blower level, a different ambient temperature is assumed by the climate control system 100.For example, an occupant may choose to set the temperature in the cabin to be at a setpoint that is 1 C cooler (i.e. lower) than the midpoint. This can be achieved by using the lowest blower power / fan speed corresponding to a cooler ambient temperature, for example 12°C. So for a cooler setpoint, the relationship curve may be selected to be, for example, 3°C warmer. This means that if the setpoint is 1°C cooler and the ambient temperature is 12°C outside, the 15°C blower relationship curve may be used which can operate at the minimum blower power and is still capable of delivering the cooler requested setpoint temperature in a 12°C ambient environment.

[0068] In a similar example, if the occupant chooses to set the temperature in the cabin to be at a setpoint that is 1 °C warmer and it has been determined from the relationship curves of Figure 5B that the minimum blower energy which can be used to achieve this is when the external ambient is 18°C (i.e. the 18°C ambient temperature curve or extrapolated point form the curves at 18°C), then the ambient offset moves in the other direction to the previous example, and the 15°C blower relationship curve may be obtained in an 18°C ambient environment when the setpoint is increased by 1°C.

[0069] As such, from the above examples, it can be seen that using a lower blower level may reduce energy consumption of the climate control system 100.

[0070] The climate control system 100, operating according to the retrieved predetermined mapping relationship 175 to provide the desired cabin temperature setpoint, may thus operate using a lower blower speed, for more energy efficient blower operation. Advantageously, a predetermined mapping relationship is selected which uses a low blower speed to improve energy efficiency whilst maintaining the functionality of efficiently adjusting the cabin temperature towards the desired cabin temperature setpoint.

[0071] That is, the retrieved predetermined mapping relationship 175 used by the control systems discussed above may be selected by the control system 100 from a set of predetermined mapping relationships as shown in Figure 5B, and this may be based on a predetermined offset. The predetermined offset may be selected based on the difference between the desired cabin temperature setpoint and a fixed cabin temperature setpoint (e.g. between the 15°C blower relationship curve from which a fixed cabin temperature setpoint may be associated with and another blower relationship curve appropriate to the requested temperature). The retrieved predetermined mapping relationship may correspond to the climate control system operating using a lower blower speed compared to a climate control system operating according to a remainder of the set of predetermined mapping relationships, thereby providing a more energy efficient mode of operation for the blower and climate control system. Advantageously, an applicable predetermined mapping relationship can be selected from the set of predetermined mapping relationships, based on a desired cabin temperature setpoint and a fixed cabin temperature setpoint (i.e. a temperature setpoint taken as a fixed starting point, e.g. at an average comfort temperature, from which other temperature setpoints are some temperature difference away). This allows for adjustment of blower speed across a wider range of desired cabin temperature setpoints by using stored relationships, to provide energy-efficient climate control.The family of predetermined relationships in Figure 5B are determined to deliver the comfort midpoint of a temperature setpoint of 22°C. In the illustrated relationship curves, theoretical temperature setpoints are included which are a long way below 16°C, which may be the lowest selectable target temperature setpoint available to a user, to allow tolerance for extended solar correction (that is, for accommodating heating effects due to solar radiation warming the cabin). For example, for a temperature setpoint of 22°C, the 40°C predetermined relationships may be selected in a 40°C ambient temperature. However, if the temperature request is for a temperature setpoints of 21 °C, then more cooling may be required, and an interpolation between the predetermined relationships for 40°C and 45°C may be determined and used, corresponding to 43°C.

[0072] Generally, if one now considers the ambient environment of 15°C, if the occupant chooses a temperature setpoint away from the midpoint, they will get a blower power / fan speed that relates to different ambient temperature relationship curve midpoint (e.g. that for 18°C), which may be slightly higher than the midpoint blower level for an ambient temperature 15°C. This is the desired behaviour.

[0073] A further improvement may be made to midpoint relationship curves such as those of Figure 5B. When the external temperature is significantly colder than 15°C, it may not always be most appropriate (i.e. most energy efficient) to continue to increase the blower power / fan speed, if the cabin is warmer than the setpoint. In this case, reducing the blower power I fan speed may allow the cabin to cool using the external environmental influence, rather than using the energy store of the vehicle to provide power to the blower to provide this cooling. The converse of this example may apply for ambient conditions warmerthan 15°C. That is, if the cabin requires warming, this can be achieved by reducing the blower and allowing the external influence to provide the required heating.

[0074] The temperature setpoint input, which indicates the desired temperature that the climate control system is to deliver in the cabin, may comprise a user temperature setpoint input (e.g. according to a user input indicative of a desired cabin temperature) or a climate control system temperature setpoint (e.g. according to a temperature identified for the climate control system to provide by the climate control system and / or by another vehicle system).

[0075] Figure 6 illustrates a method 600 of operation of the control system 100 according to an embodiment of the invention. This example illustrates that once the desired cabin temperature setpoint 165 is achieved by the climate control system 200 by using a blower speed, a balanced blower speed 615 may then be determined and used to control the blower to maintain the desired cabin temperature. Changing the cabin climate temperature to a different temperature may require the blower to operate at a different (e.g. lower) power / fan speed than the power / fan speed that used to achieve the desired cabin temperature setpoint, to maintain the temperature, once reached. The cabin temperature may be determined to reach the desired cabin temperature setpoint, for example, by determining that a rolling average of the cabin temperature over a predetermined temperature sensor time window is within a predetermined tolerance range of the desired cabin temperature.According to the method in Figure 6, the control system 100 may receive an indication of the desired cabin temperature setpoint 165, and a sensed cabin temperature signal 185 indicative of a sensed temperature of the cabin (e.g. as detected by a temperature sensor in the cabin). At step 606, the control system may determine that the desired cabin temperature setpoint 165 matches the sensed cabin temperature 185 (e.g. if the sensed cabin temperature and the desired cabin temperature are within a tolerance of e.g. ±0.5°C to each other, and / or are within the tolerance over a rolling average fora predetermined time period of e.g. 15 seconds, or 30 seconds). If the match is determined in step 606, the control system 100 may proceed to step 610 and determine a balanced blower speed 615 which may be transmitted to the climate control system to provide climate control at that balanced blower speed 615 and maintain the desired cabin temperature setpoint 165. Advantageously, the blower may be controlled to operate at a different blower speed once the sensed cabin temperature reaches the desired cabin temperature setpoint, which may be a lower fan speed / blower power mode than that used to achieve the desired cabin temperature setpoint, thereby improving energy efficiency of blower operation.

[0076] The control system 100 in some examples may account for external thermal effects on the temperature in the vehicle cabin (for example due to strong sunshine, or cold winds). The control system 100 may be configured to determine the blower speed further based on the external thermal indicator signal 155, to adjust the cabin temperature towards the desired cabin temperature setpoint. The external thermal effect may act to change the cabin temperature. For example, strong sunshine, snowfall, cold winds, stopping the vehicle in shade or any other external temperature influence. In some examples the blower speed may be further based on the cabin temperature signal 185. For example, if the weather outside is very hot but the cabin temperature signal is also of high temperature then the external temperature influence may not contribute to determining the blower operation, but if the cabin temperature signal is of low temperature then the external temperature influence may contribute to how the blower is to operate to reach the desired cabin temperature setpoint. In some examples the blower speed may be further based on the desired cabin temperature setpoint 165. For example, if the desired cabin temperature setpoint is a high temperature and the external temperature is also hot, then the influence of the external temperature may not contribute to determining the blower operation, but if the desired cabin temperature setpoint is a low temperature and the external temperature is also hot, then the external temperature influence may contribute to how the blower is to operate to reach the desired cabin temperature setpoint.

[0077] Thus, the external temperature indicated by the external thermal indicator signal 155 may be used to select the predetermined mapping as above, but may additionally be used to determine how and when to control the climate control system based on the external temperature affecting the cabin, further to consideration in selecting the predetermined mapping. Advantageously, the external ambient conditions affecting the cabin temperature, such as hot sunny weather, can be accounted for, and the blower can be controlled to provide air to reach and / or maintain the desired cabin temperature setpoint in accordance with the effect of the external ambient conditions.

[0078] For example, the control system 100 may be configured to determine if the external temperature is lower than the sensed cabin temperature, and if the sensed cabin temperature is higher than the desired cabintemperature setpoint. If so, the control system may be configured to output the control signal 195 to the climate control system 200 to cause the blower to operate at a reduced blower speed than a current blower speed. Advantageously, the ambient conditions acting to cool the cabin temperature may be used to cool the cabin by lowering the blower speed. This action takes advantage of the cool ambient conditions to lower the cabin temperature and reduce the power used by the climate control system to use the blower to control the cabin temperature. A cooler external temperature may be used to cool the internal air by using a lower blower speed to pass the cool external air into the cabin at low blower speed. A higher blower speed may act to heat the air passing by the blower into the cabin or give the perception of warmer air.

[0079] As another example, the control system 100 may be configured to determine if the external temperature is higher than the sensed cabin temperature, and if the sensed cabin temperature is lower than the desired cabin temperature setpoint. If so, the control system may be configured to output the control signal 195 to the climate control system 200 to cause the blower to operate at a reduced blower speed than a current blower speed. Advantageously, the ambient conditions acting to heat the cabin temperature may be used to heat the cabin by lowering the blower speed. This action takes advantage of the warm ambient conditions to adjust the cabin temperature and reduce the power used by the climate control system to control the cabin temperature. A warmer external temperature may be used to heat the internal air by using a lower blower speed to pass the heated external air into the cabin at low blower speed. A higher blower speed may act to make the heated air, if provided at higher speed, feel cool to an occupant of the cabin.

[0080] Figure 7 illustrates a system 700 comprising the control system 100 discussed above and a climate control system 200. The climate control system 200 comprises a blower 810. In some examples, the climate control system 200 may comprise and / or control a heating element 820. In some examples, the climate control system 200 may comprise and / or control an air conditioning element 830. The climate control system 200 is configured to receive the control signal 195 output by the control system 100 and use that signal to generate a corresponding blower control signal 815 to cause the blower 810 to operate at the blower speed.

[0081] In some examples, the control system 100 may be configured to determine both the blower power level I fan speed and the discharge temperature (to be provided by the heating element 820 or air conditioning element 830) required. The greater the difference between the ambient temperature and the requested cabin temperature, the greater the power (amount of hot or cold) that the system needs to deliver. This difference is a combination of the temperature difference between the delivery air temperature and the cabin temperature on one hand, and the blower level on the other. The heating element 820 or air conditioning element 830 (which may be considered to be a thermal system) may be controlled to create the hot and cold sources for the climate control system to blend the desired air temperature from. Requesting extreme temperatures (very hot or very cold) from the thermal system alone is not energy efficient, so larger blower levels may also be used to make the air temperature request on the thermal system less extreme and deliver the requested temperature.

[0082] However, when the power transfers are smaller (e.g. the cabin temperature request is closer to the current ambient temperature), a lower blower level can be selected. The examples disclosed herein allow for intelligentcontrol of the blower level request, by intelligent selection of a blower level, for example based on selecting the default (22°C) temperature setpoint blower operational curve 510 from a different ambient temperature curve. When a different temperature setpoint is requested, if the temperature request is for more cooling than the current ambient and midpoint temperature setpoint would need, then it is appropriate to assume the ambient temperature is hotter and so more cooling is required. Likewise, if the temperature request is for more heating than the midpoint temperature setpoint, then it may be assumed that the ambient temperature is colder than the cabin temperature and it is appropriate to generate more heating.

[0083] In some cases, the control system may determine that a higher blower level should be used because this reduces the temperature differences that the thermal system needs to generate, and in some cases the control system may choose a lower blower because the temperatures are less extreme. But the knowledge of which blower level is appropriate to the power delivery to achieve the requested temperature setpoint is built into I derivable from the 22°C temperature setpoint blower operational curve family of Figure 5B. By selecting a blower relationship curve 522, 524, 526, 528, 530, 532, 534, 536 from a different ambient temperature from the 22°C temperature setpoint blower operational curve 510 (of Figure 5A), there is provided a way of selecting the relationship appropriate to the current power delivery required to achieve the requested cabin temperature setpoint. The blower level curve families such as that in Figure 5B may be derived by considering how to deliver the power needed to achieve a 22°C temperature setpoint. That is, they indicate how a particular power can be delivered to achieve a particular temperature setpoint. When the requested cabin temperature can be achieved using a different power, away from the power for delivering the 22°C temperature setpoint, then the blower relationship curve appropriate to that power can be identified by assuming a different ambient temperature.

[0084] In examples, the climate control system 200 may comprises or may be configured to control a heating element 820. The control system 100 may be configured to determine an adjusted discharge temperature based on the external temperature and the desired cabin temperature setpoint 165. The adjusted discharge temperature may be determined so that it would cause the climate control system to heat the cabin temperature towards the desired cabin temperature setpoint. The control system 100 may be configured to output the control signal 195 to the climate control system 200 to cause the heating element 820 to operate at the adjusted discharge temperature (e.g. by way of the climate control system 200 outputting a heating element control signal 825 to the heating element 820). Advantageously, the climate control system may be further controlled to adjust the air discharge temperature based on the effect of the external temperature on the cabin temperature by using a heating element 820. If adjusting the blower speed is determined not to be sufficient to achieve the desired cabin temperature, the heating element may also be used to heat the air provided to the cabin.

[0085] In examples, the climate control system 200 may comprises or may be configured to control an air conditioning element 830, the control system 100 may be configured to determine an adjusted discharge temperature based on the external temperature and the desired cabin temperature setpoint 165. The adjusted discharge temperature may be determined to cool the cabin temperature towards the desired cabin temperature setpoint. The control system 100 may be configured to output the control signal 195 to the climate control system 200 to cause the air conditioning element 830 to operate at the adjusted discharge temperature (e.g. by way of theclimate control system 200 outputting an air conditioning element control signal 835 to the heating element 830). Advantageously, the climate control system 200 may be further controlled to adjust the air discharge temperature based on the effect of the external temperature on the cabin temperature by using an air conditioning heating element. If adjusting the blower speed is determined not to be sufficient to achieve the desired cabin temperature, the air conditioning element may also be used to cool the air provided to the cabin.

[0086] 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.

Claims

CLAIMS1. A control system for controlling a climate control system of a vehicle, the climate control system comprising a blower, the control system comprising one or more processors collectively configured to:receive an external thermal indicator signal indicative of an external ambient temperature sensed by an external ambient temperature sensor of the vehicle;receive a cabin temperature setpoint signal in response to a temperature setpoint input, the cabin temperature setpoint signal indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle;retrieve, in dependence on the desired cabin temperature setpoint and the external ambient temperature, a predetermined mapping relationship mapping a blower speed to an energy error value, the energy error value indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint;determine a blower speed based on the desired cabin temperature setpoint and the retrieved predetermined mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; andoutput a control signal to the climate control system to cause the blower to operate at the blower speed.

2. The control system of claim 1 , wherein:the control system is configured to retrieve the predetermined mapping relationship by selecting the predetermined mapping relationship from a set of predetermined mapping relationships based on a predetermined offset, the predetermined offset selected based on a difference between the desired cabin temperature setpoint and a fixed cabin temperature setpoint.

3. The control system of claim 2, wherein the control system is configured to select the predetermined mapping relationship corresponding to the climate control system operating using a lower blower speed compared to a climate control system operating according to a remainder of the set of predetermined mapping relationships.

4. The control system of any preceding claim, wherein the control system is configured to:receive a cabin temperature signal indicative of a sensed cabin temperature sensed by an internal temperature sensor of the vehicle; anddetermine the blower speed further based on the sensed cabin temperature to adjust the cabin temperature towards the desired cabin temperature setpoint.

5. The control system of claim 4, wherein the control system is configured to, in dependence on the sensed cabin temperature signal reaching the desired cabin temperature setpoint, determine a balanced blower speed to maintain the cabin temperature at the desired cabin temperature setpoint.

6. The control system of any preceding claim, wherein the control system is configured to:determine the blower speed further based on the external thermal indicator signal to adjust the cabin temperature towards the desired cabin temperature setpoint.

7. The control system of any of claims 4 to 6, wherein, if the external temperature is lowerthan the sensed cabin temperature, and the sensed cabin temperature is higher than the desired cabin temperature setpoint, the control system is configured to output the control signal to the climate control system to cause the blower to operate at a reduced blower speed than a current blower speed.

8. The control system of any of claims 4 to 7, wherein, if the external temperature is higher than the sensed cabin temperature, and the sensed cabin temperature is lower than the desired cabin temperature setpoint, the control system is configured to output the control signal to the climate control system to cause the blower to operate at a reduced blower speed than a current blower speed.

9. The control system of any preceding claim, wherein the climate control system comprises a temperature change element, and wherein the control system is configured to:determine an adjusted discharge temperature based on the external ambient temperature and the desired cabin temperature setpoint, the adjusted discharge temperature determined to heat the cabin temperature towards the desired cabin temperature setpoint; andoutput the control signal to the climate control system to cause the temperature change element to operate at the adjusted discharge temperature.

10. A system comprising:the control system of any preceding claim; anda climate control system comprising a blower.

11. A vehicle comprising the system of claim 10 or the control system of any of claims 1 to 9.

12. A method for controlling a climate control system of a vehicle, the method comprising:receiving an external thermal indicator signal indicative of an external ambient temperature sensed by an external ambient temperature sensor of the vehicle;receiving a cabin temperature setpoint signal in response to a temperature setpoint input, the cabin temperature setpoint signal indicative of a desired cabin temperature setpoint for a cabin temperature of the vehicle;retrieving, in dependence on the desired cabin temperature setpoint and the external ambient temperature, a predetermined mapping relationship mapping a blower speed to an energy error value, the energy error value indicative of an amount of energy required to be transferred to or from the vehicle cabin to achieve the desired cabin temperature setpoint;determining a blower speed based on the desired cabin temperature setpoint, and the predetermined mapping relationship to adjust the cabin temperature towards the desired cabin temperature setpoint; and outputting a control signal to the climate control system to cause the blower to operate at the blower speed.

13. The method of claim 12, wherein:the retrieved predetermined mapping relationship is selected from a set of predetermined mapping relationships based on a predetermined offset; and the predetermined offset is selected based on the difference between the desired cabin temperature setpoint and a fixed cabin temperature setpoint.

14. The method of claim 12 or claim 13, comprising selecting the predetermined mapping relationship corresponding to the climate control system operating using a lower blower speed compared to a climate control system operating according to a remainder of the set of predetermined mapping relationships.

15. Computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method according to any of claims 12 to 14.

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