Method for managing an air conditioning system in a motor vehicle and motor vehicle

Abstract

The invention relates to a method for managing an air conditioning system in a motor vehicle comprising the following steps: performing a relevance review by testing the veracity of several predefined conditions including at least one outside temperature condition and one humidity level condition in the passenger compartment and executing a command to open the air intake flaps according to the result of the tests performed, such that when all the tested conditions are met, then a default opening command is executed allowing a given volume of outside air to enter the passenger compartment and / or to renew the air in the passenger compartment according to a given air renewal rate;When at least one of the tested conditions is not met, then a modified opening command is executed, the modified opening command increasing the volume of outside air entering the vehicle and / or increasing the air exchange rate compared to the default opening command. Figure to be published with the abbreviation: Fig. 1;

Description

Title of the invention: Method for managing an air conditioning system in a motor vehicle and motor vehicle

[0001] The invention is in the field of air conditioning for vehicles such as hybrid or electric motor vehicles.

[0002] In the context of the fight against climate change, current policies tend to promote the production and use of hybrid or electric motor vehicles. It should be noted that a hybrid vehicle comprises both a thermal combustion engine and an electric motor.

[0003] Air conditioning is a comfort feature increasingly common in motor vehicles. A standard automotive air conditioning system comprises four main components: a compressor, a condenser, an expansion valve, and an evaporator. These four components are arranged within a closed circuit through which a refrigerant (or heat transfer fluid) circulates. Some vehicles are equipped with systems that provide both air conditioning (or cooling) and heating for the passenger compartment. In these systems, certain components have a dual function. For example, they include two heat exchangers that alternately act as condensers or evaporators depending on whether the system is operating in air conditioning or heating mode.Air conditioning systems consume electricity, and for electric or hybrid vehicles, this consumption impacts the vehicle's range. Therefore, there is a need to optimize the management of air conditioning systems to reduce their electricity consumption. It is nevertheless important to prevent window fogging and ensure user comfort through sufficient air exchange.

[0004] Document FR2845034 describes a motor vehicle air conditioning unit equipped with an air conditioning system and an electronic control device. The unit further includes a device for estimating the mass flow rate of a refrigerant in the system, first estimation means for providing a value for the air temperature at the evaporator inlet, and second estimation means for providing a value for the air temperature at the evaporator outlet. The electronic control device is adapted to estimate the atmospheric humidity at the evaporator inlet based on the value provided by the device estimating the refrigerant mass flow rate and the values ​​provided by the first and second estimation means. The described installation is interesting in that it It doesn't use a hygrometer to measure the air humidity level but instead estimates it based on the mass flow rate of the refrigerant. The goal is to control the relative humidity, particularly to prevent windows from fogging up. The proposed solution for reducing energy consumption is to dry the air, for example, by installing air conditioning and optimizing the air temperature at the evaporator outlet. While interesting, the proposed system can be improved, especially regarding the management of air renewal within the vehicle's cabin.

[0005] Document WO2018042961 describes a vehicle air conditioning system that prevents window fogging more precisely, taking into account the passengers' metabolism. A vehicle air conditioning system comprises an air conditioning unit, a humidity control unit, a control unit, and metabolic rate sensing units. The air conditioning unit has an air path that directs the air conditioning air into the vehicle's passenger compartment. The humidity control unit regulates the humidity in the vehicle's passenger compartment. The control unit controls the humidity control unit. The metabolic rate sensing units detect the metabolic rate of the passengers in the vehicle's passenger compartment. The control unit commands the humidity control unit based on the metabolic rate.The proposed system is interesting in terms of preventing fogging, but it involves significant costs due to the presence of metabolic rate detection units that must be installed in the seats. A more economical solution would be beneficial.

[0006] US patent 2012009859 relates to a system and method for selecting air intake between 100% fresh air and 100% recirculated air modes for optimal heating / cooling performance, fuel economy, and / or limited high-voltage battery power consumption. The system and method include a partial recirculation control strategy in which the air inlet door is progressively moved to any position taking into account the cooling / heating loads and the probability of fogging in the cabin. As the cooling / heating loads increase, the air inlet door switches to 100% recirculation mode. As the probability of fogging increases, the air inlet door switches to 100% fresh air mode.By selectively choosing a setting between 100% recirculation and 100% fresh air, fuel economy and / or high-voltage battery energy consumption are optimized without compromising passenger comfort or causing fogging on interior windows. The proposed solution is promising but could be further improved. particularly with regard to the management of air renewal in the vehicle's passenger compartment.

[0007] The invention aims to address at least one of the problems presented by the prior art by proposing a method and a system for managing an air conditioning installation in a motor vehicle, and the associated vehicle, which makes it possible to reduce the electrical energy consumption of an air conditioning installation while making it possible to guarantee the vehicle's performance in terms of comfort (including the rate of air renewal in the passenger compartment) and / or in terms of preventing the risk of fogging of the windows.

[0008] According to a first aspect, the invention relates to a method for managing an air conditioning system in a motor vehicle, the vehicle comprising a passenger compartment and being equipped with an electronic control unit configured to control the opening and closing of one or more air intake flaps of the air conditioning system. The method is remarkable in that it comprises the following steps: performing a relevance check by testing the veracity of several predefined conditions, including at least one outside temperature condition and one humidity level condition in the passenger compartment, and executing a command to open the air intake flap(s) based on the results of the tests performed, such that:

[0009] when all the tested conditions are met, then a default opening command is executed allowing a given volume of outside air to enter the passenger compartment and / or allowing the air in the passenger compartment to be renewed according to a given air renewal rate;

[0010] when at least one of the tested conditions is not met, then a modified opening command is executed, the modified opening command increasing the volume of outside air entering the vehicle and / or increasing the rate of air renewal compared to the default opening command.

[0011] As will be understood from the definition just given, the invention consists of reducing electrical energy consumption by optimizing the volume of outside air entering the passenger compartment so that it is as low as possible while guaranteeing the vehicle's performance in terms of comfort (including the air exchange rate in the passenger compartment) and / or in terms of preventing the risk of window fogging. Threshold values ​​are parameterized, defining optimal conditions under which the volume of outside air entering the passenger compartment can be limited, and as long as these conditions are met, it is this minimum volume of air (i.e., reduced compared to known management methods) that enters the passenger compartment, thus reducing electrical energy consumption.

[0012] Thus, initially, the invention will define and parameterize a default opening command according to which a given volume of outside air enters the passenger compartment. The outside air entering the vehicle prevents the windows from fogging up and / or renews the air in the passenger compartment. This outside air intake into the passenger compartment is achieved by opening the air intake flap(s) of the air conditioning system. The control for opening the flap(s) can be either continuous to a given degree of opening, or intermittent according to a given opening frequency, defining an air renewal rate.

[0013] For example, the default opening command may be to fully open the air intake flap(s) every 80 minutes for a duration of 2 minutes to renew the air in the vehicle's passenger compartment. In another example, the air is continuously renewed, and the default opening command is to continuously open the air intake flap(s) to a degree of 40%.

[0014] The default opening command allows for the definition of a minimum volume of outside air entering the vehicle, by setting the longest possible opening frequency and / or by setting the smallest possible opening angle. According to the invention, the default opening command is only executed when conditions permit, that is, when this minimum volume of incoming air is considered sufficient to guarantee good vehicle performance in terms of comfort (including the air exchange rate in the passenger compartment) and in terms of preventing the risk of window fogging.

[0015] In a second step, the invention consists of identifying the situations in which this default opening command is unsuitable, that is to say, the conditions in which this minimum volume of incoming air is considered insufficient. The default opening command is considered unsuitable when its execution would not allow sufficient outside air to enter the vehicle's passenger compartment to guarantee the vehicle's performance in terms of comfort (including the air exchange rate in the passenger compartment) and / or in terms of preventing the risk of window fogging.

[0016] The appropriateness of executing the default opening command is verified by testing several conditions, including at least one outside temperature condition and one humidity condition. In preferred embodiments, the appropriateness of executing the default opening command is verified by testing several conditions, including an additional condition related to the number of people in the vehicle and / or a condition related to changes in the humidity level. When the default opening command is deemed unsuitable, the process will execute a modified opening command parameterized according to of the situation described by the test results. The volume of incoming air, although greater than the minimum required, remains as low as possible and therefore minimal relative to the vehicle's operating conditions. The process thus optimizes the volume of outside air entering the vehicle's passenger compartment, thereby reducing the amount of electrical energy consumed by the vehicle. When the vehicle is electric or hybrid, this reduction in electrical energy consumption increases the vehicle's driving range.

[0017] It has indeed been found that cooling or heating the air from outside the vehicle is one of the main causes of electrical energy consumption in a motor vehicle's air conditioning system. The method according to the invention makes it possible to optimize the volume of outside air entering the vehicle's passenger compartment by defining the situations in which a minimum volume of outside air is sufficient to ensure the vehicle's performance. This minimum volume of outside air used by the management method according to the invention is reduced compared to the volume of incoming air conventionally used by prior art management methods.

[0018] Furthermore, the method according to the invention is remarkable in that it offers the possibility of modifying (i.e., increasing) the volume of incoming outside air when necessary, while keeping it as low as possible, and even of defining situations in which it is not necessary to bring outside air into the vehicle. The method according to the invention thus allows for precise management of the incoming volume of outside air and / or the appropriateness of an outside air intake in the vehicle.

[0019] Preferably, the test of the outside temperature condition includes measuring the outside temperature of the vehicle and comparing it to a reference temperature, and the condition is met when the measured outside temperature is greater than or equal to the reference temperature; preferably, the reference temperature is chosen between 15 and 25 °C; more preferably, between 17 and 22 °C or between 18 and 20 °C.

[0020] Preferably, the humidity level condition test includes measuring the humidity level in the passenger compartment and the condition is met when the measured humidity level is equal to or greater than an initial reference humidity level; preferably, the initial reference humidity level is between 80 and 90%; more preferably between 82 and 88%.

[0021] According to one embodiment, the vehicle comprising doors, the method is notable in that the tested conditions further include a condition for the evolution of the humidity level when the vehicle doors are closed. Preferably, the test of the humidity level evolution condition It includes at least two measurements of the humidity level in the passenger compartment over a given time interval and their comparison to determine a humidity differential, and the condition is met when the determined humidity differential is less than or equal to a reference differential. For example, the given time interval is between 1 and 120 seconds; preferably, between 10 and 90 seconds; more preferably, between 30 and 50 seconds.

[0022] Alternatively, the test of the condition of evolution of the humidity level in the passenger compartment is carried out continuously so as to determine a continuous humidity differential, and the condition is met when the determined humidity differential is less than or equal to a reference differential.

[0023] Advantageously, the reference differential is between 2 and 5% per minute, preferably between 3 and 4% per minute.

[0024] In a preferred embodiment, when the humidity change condition is not met, the determined humidity differential is compared to a critical humidity differential. When the determined humidity differential is greater than or equal to the critical humidity differential, the air intake flap(s) are opened according to a modified command that is executed when the cabin humidity is equal to or greater than an adjusted reference humidity level, the adjusted reference humidity level being chosen to be lower than the initial reference humidity level. For example, the critical humidity differential is between 5 and 8% per minute, preferably between 6 and 7% per minute. Advantageously, the adjusted reference humidity level is between 60 and 80%; more preferably between 65 and 75%.

[0025] Preferably, when the humidity level change condition is not met, the determined humidity differential is compared to a critical humidity differential, and when the determined humidity differential is less than the critical humidity differential, the air intake flap(s) are opened according to a modified command that is executed when the cabin humidity level is equal to or greater than an intermediate reference humidity level, the intermediate reference humidity level being chosen to be lower than the initial reference humidity level and higher than the adjusted reference humidity level. Advantageously, the intermediate reference humidity level is between 70 and 85%; more preferably between 75 and 82%.

[0026] According to one embodiment, the tested conditions further include a condition for the number of people present. Preferably, the test of the condition for the number of people present includes determining the number of people in the vehicle and comparing it to a reference number, and said condition is This field is filled in when the number of people in the vehicle is equal to or less than the reference number. Preferably, the reference number is 1 or 2.

[0027] According to one embodiment, the control for opening the damper(s) is a continuous opening control, such that the default opening control defines a continuous opening of the damper(s) according to a given initial degree of opening and the modified opening control(s) define a continuous opening of the air inlet damper(s) according to an adjusted degree of opening greater than the initial degree of opening.

[0028] Alternatively, the control for opening the flap(s) is an intermittent opening control, such that the default opening control defines an intermittent opening of the flap(s) according to a given initial frequency and the modified opening control(s) define an intermittent opening of the air inlet flap(s) according to an adjusted opening frequency higher than the initial frequency.

[0029] In a preferred embodiment, the control for opening the air inlet flap(s) is an intermittent opening control, and when the condition of the number of people present is not met, then the adjusted opening frequency corresponds to the initial frequency divided by a divisor corresponding to the number of people present in the vehicle divided by the reference number; preferably, the initial frequency corresponds to an opening of the flap(s) in a unit of time chosen to be between 30 and 100 minutes.

[0030] Advantageously, given that the vehicle has doors, the method is notable in that the control for opening the flap(s) is an intermittent opening control and in that, after the vehicle doors are closed, when the humidity level condition is not met, the air conditioning system is activated with the flap(s) closed and the opening of the flap(s) is initiated after a predetermined latency period; preferably, the latency period is less than or equal to the period associated with the opening frequency of the flap(s); for example, the latency period is less than or equal to 0.8 times said period. The invention is notable in that there is no outside air intake in the vehicle during short journeys when conditions permit, thus reducing the electrical energy consumption of the air conditioning system as much as possible while allowing the air to be dehumidified.

[0031] Preferably, the control for opening the flap(s) is a continuous opening control and the initial degree of opening given corresponds to a partial opening of said air inlet flap(s) which is less than or equal to 70% of the total opening; preferably a partial opening between 40 and 60% of the total opening.

[0032] Advantageously, since the vehicle has doors, the method is notable in that the control for opening the flap(s) is a continuous opening control and in that, after the vehicle doors are closed, the opening of the flap(s) is initiated after a predetermined delay; preferably, the delay is between 10 and 38 minutes, more preferably between 15 and 30 minutes. The invention is notable in that there is no outside air intake in the vehicle during short journeys when conditions permit, thus reducing the electrical energy consumption of the air conditioning system as much as possible.

[0033] According to a second aspect, the invention relates to a management system for an air conditioning installation of a motor vehicle, the vehicle comprising a passenger compartment, the system comprising an electronic control unit configured to control the opening and closing of one or more air inlet flaps of the air conditioning installation, the system is remarkable in that it is configured to implement the management method according to the first aspect.

[0034] According to one embodiment, the system includes or uses a temperature sensor configured to determine the temperature outside the vehicle; a humidity sensor arranged to determine the humidity level inside the passenger compartment and, optionally, a means for determining the number of people present in the passenger compartment of the vehicle.

[0035] According to a third aspect, the invention relates to a vehicle comprising a passenger compartment and an air conditioning system having at least one air inlet flap that can be opened so that outside air can enter the passenger compartment or that can be closed, the vehicle further comprising an electronic control unit configured to control the opening of the air inlet flap(s) of the air conditioning system, the vehicle is notable in that it includes test equipment including a temperature sensor configured to determine the temperature outside the vehicle; a humidity sensor arranged to determine the humidity level inside the passenger compartment and, optionally, a means for determining the number of people present in the passenger compartment of the vehicle;and the electronic control unit is configured to implement the process according to the first aspect using data from the test equipment; preferably, the vehicle is an electric or hybrid powered vehicle.

[0036] According to a fourth aspect, the invention relates to a vehicle comprising a passenger compartment and an air conditioning system having at least one air inlet flap that can be opened so that outside air can enter the passenger compartment or being able to be closed, the vehicle is remarkable in that it also includes a system according to the second aspect.

[0037] The invention will be well understood and other aspects and advantages will become clear upon reading the following description given with reference to the attached drawing plate on which

[0038] [Fig-1] [Fig.1] is a graph illustrating the variations in autonomy of different Electric vehicles depending on the outside temperature.

[0039] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other elements or means in the vehicle to which it relates, or other steps in the use considered. It is understood that the term "include" includes the terms "consist of".

[0040] The invention relates to a method for managing an air conditioning system in a motor vehicle, the vehicle comprising a passenger compartment and equipped with an electronic control unit configured to control the opening and closing of one or more air intake flaps of the air conditioning system. The invention also relates to a system and a vehicle equipped with an electronic control unit configured to implement said method. The method, the system, and the vehicle are described jointly.

[0041] The functions for opening or closing the air conditioning system's flap(s) are implemented by sending instructions from the electronic unit or the system to said flaps, for example via a multiplexed network onboard the vehicle, or via a control device specific to said system. The electronic unit will typically include at least one memory and at least one computer.

[0042] It should be noted, if necessary, that multiplexed networks are digital communication networks that allow electrical equipment or subsets of electrical equipment to communicate with each other using a reduced number of wires. The implementation of such multiplexed networks in a vehicle is known to those skilled in the art and will not be described in further detail. By way of example, the invention can implement a CAN (Controller Area Network), LIN (Local Interconnect Network), MOST (Media Oriented System Transport), Flexray, or other types of multiplexed networks.

[0043] The method according to the invention is remarkable in that it comprises the following steps: performing a relevance examination by testing the veracity of several predefined conditions, including at least one outside temperature condition and one humidity level condition for the passenger compartment, and executing an opening command. of the air intake flap(s) depending on the results of the tests carried out, such that:

[0044] when all the tested conditions are met, then a default opening command is executed allowing a given volume of outside air to enter the passenger compartment and / or allowing the air in the passenger compartment to be renewed according to a given air renewal rate;

[0045] when at least one of the tested conditions is not met, then a modified opening command is executed, the modified opening command increasing the volume of outside air entering the vehicle and / or increasing the air renewal rate compared to the default opening command.

[0046] The vehicle's air conditioning system is configured to blow air at a given temperature into the vehicle's passenger compartment. The blown air can be selected to consist of air already present in the passenger compartment (100% recirculated air and 0% incoming air), for example, when the air intake flap(s) are closed. It can consist of incoming outside air only (0% recirculated air and 100% incoming air), for example, when the air intake flap(s) are fully open. It can consist of a mixture of incoming and recirculated air (for example, 40% incoming air and 60% recirculated air), for example, when the air intake flap(s) are partially open to a given degree.

[0047] According to one embodiment, the control for opening the flap(s) is an intermittent opening control such that the default opening control defines an intermittent opening of the flap(s) according to a given initial frequency and the modified opening control(s) define an intermittent opening of the air inlet flap(s) according to an adjusted opening frequency higher than the initial frequency.

[0048] Preferably, the initial frequency corresponds to the opening of the flap(s) within a time unit chosen to be between 30 and 100 minutes, more preferably between 40 and 90 minutes or between 50 and 80 minutes. The initial frequency is determined based on the passenger compartment volume. In one embodiment of the invention, the initial frequency also depends on the reference number of people present in the vehicle and corresponds to an estimate of the amount of carbon dioxide in the passenger compartment. It is chosen to allow for air renewal when the estimated carbon dioxide content in the passenger compartment has reached approximately 2%. Preferably, the intermittent opening of the flaps is carried out to a degree of opening between 80 and 100% of the total opening; more preferably between 90 and 100% of the total opening.Intermittent opening allows for air renewal in the passenger compartment, and the opening time is calculated accordingly based on the volume of the passenger compartment. The opening time of the shutter(s) is, for example, between 1 and 5 minutes, preferably between 2 and 4 minutes.

[0049] According to one embodiment, the control for opening the damper(s) is a continuous opening control, such that the default opening control sets the damper(s) to open continuously to a given initial degree, and the modified opening control(s) set the air inlet damper(s) to open continuously to an adjusted degree of opening greater than the initial degree. The use of a continuous opening control is advantageous in that it limits the noise generated by the closing of the damper(s).

[0050] Preferably, the control for opening the flap(s) is a continuous opening control and the initial degree of opening given corresponds to a partial opening of said air inlet flap(s) which is less than or equal to 70% of the total opening; preferably a partial opening between 30 and 60% of the total opening or between 40 and 50% of the total opening.

[0051] Advantageously, since the vehicle has doors, the method is remarkable in that the control for opening the flap(s) is a continuous opening control and in that, after the vehicle doors are closed, the opening of the flap(s) is initiated after a predetermined delay; preferably, the delay is between 10 and 40 minutes, more preferably between 15 and 30 minutes. It has been determined that the majority of journeys made are short, i.e., less than 40 minutes, or even less than 30 or 20 minutes. Not allowing air in for an initial period saves electrical energy and thus increases the range of electric or hybrid vehicles. It will be understood that the delay begins when the doors are closed.

[0052] The invention will, firstly, determine optimal opening conditions for the air intake flap(s) allowing the minimum quantity of air necessary to ensure proper vehicle performance to enter. These conditions are then tested, and the default opening command is confirmed when the vehicle is in these minimum operating conditions.

[0053] According to a preferred embodiment of the invention, the tested conditions further include a condition related to the number of people present in the passenger compartment of the vehicle, and / or a condition related to the evolution of the humidity of the passenger compartment.

[0054] It should be recalled, if necessary, that the hygrometry rate is the ratio of the amount of water vapor contained in the air to the maximum possible amount of water vapor and corresponds to the relative humidity. The air saturation threshold (i.e., the maximum possible amount of water vapor) increases with temperature in a manner known to those skilled in the art. The humidity level is expressed as a percentage. 100% corresponds to air saturated with water vapor, 0% to perfectly dry air (never achieved). According to the invention, the desired humidity level in the vehicle is between 30 and 60%, preferably between 40 and 60%.

[0055] According to the invention, the tested conditions include at least one outside temperature condition, the condition is met when the outside temperature of the vehicle is greater than or equal to a reference temperature.

[0056] The vehicle therefore includes at least one temperature sensor configured to determine the temperature outside the vehicle and to transmit the result of the measurements taken to the electronic control unit.

[0057] Indeed, it has been found that the outside temperature is a good indicator for assessing the risk of vehicle fogging. Thus, when the outside temperature is sufficiently high (for example, when it is 20°C or higher), the risk of fogging is low or even non-existent. It is therefore possible to introduce only a minimal amount of outside air into the vehicle. Conversely, the lower the outside temperature (for example, when it is below 15°C), the greater the risk of fogging becomes, and it is preferable to introduce a larger quantity of outside air into the vehicle to combat the risk of fogging.

[0058] For example, the reference temperature can be the dew point temperature below which condensation naturally forms on the inner surface of the vehicle windows, i.e., the surface of the windows facing the interior of the passenger compartment. The dew point temperature is determined by the electronic control unit based on the humidity level inside the passenger compartment and the window temperature, which is determined by the outside temperature of the vehicle; such that the temperature condition is met when the outside temperature is higher than the dew point temperature. In this embodiment of the method, the reference temperature is determined in situ and at a predetermined frequency or continuously during the implementation of the method.

[0059] Alternatively, the reference temperature is pre-recorded and compared to the outside temperature of the vehicle. When the reference temperature is chosen (pre-recorded) and not determined in situ, a person skilled in the art would benefit from choosing a reference temperature between 15 and 25 °C; more preferably, between 17 and 22 °C or between 18 and 20 °C. The choice of the reference temperature may be dependent on or independent of measurements of the humidity level in the passenger compartment and / or the number of people in the vehicle.

[0060] According to one embodiment, the process comprises two reference temperatures, namely a first reference temperature and a second reference temperature The condition is met when the outside temperature is greater than or equal to the second reference temperature. This variant of the process allows the default opening command to be executed when temperature conditions permit, but also allows for the definition of critical conditions (i.e., below the first reference temperature) in which the risk of fogging is high enough to necessitate drawing in a significant amount of outside air. Between the two reference temperatures, the process will modulate the amount of incoming air based on one or more factors chosen from among the number of people in the vehicle, the humidity level inside the passenger compartment, and changes in the humidity level. For example, the first reference temperature is between 13 and 17 °C, and the second reference temperature is between 19 and 25 °C.Preferably, the first reference temperature is between 14 and 16 °C and / or the second reference temperature is between 20 and 23 °C.

[0061] The choice and / or determination of the value of the reference temperature(s) is part of the parameters of the process according to the invention.

[0062] According to the invention, the tested conditions include at least one humidity level condition. Preferably, the humidity level condition test includes measuring the humidity level in the passenger compartment, and the condition is met when the measured humidity level is equal to or greater than an initial reference humidity level; preferably, the initial reference humidity level is between 80 and 90%; more preferably between 82 and 88%.

[0063] The vehicle therefore includes at least one humidity sensor arranged to determine the humidity level inside the passenger compartment and to transmit the result of the measurements taken to the electronic control unit.

[0064] According to the invention, the reference humidity level constitutes a trigger threshold. When this threshold is exceeded, i.e., when the humidity level condition is not met, the opening or increasing of the degree of opening of the air inlet damper(s) can be controlled. When the control for opening the damper(s) is an intermittent opening control, exceeding the trigger threshold can generate an immediate opening of the damper(s) to a predetermined degree of opening (i.e., without waiting for the end of the period) and maintain the damper(s) open until the measured humidity level is again lower than the reference humidity level.

[0065] According to one embodiment, the vehicle comprising doors, the method is notable in that the opening control of the flap(s) is an intermittent opening control and in that after the vehicle doors are closed, when the humidity level condition is not met, the air conditioning system is The system is activated with the flaps closed, and the opening of the flap(s) is initiated after a predetermined delay. Indeed, after the doors are closed, the need for air renewal in the passenger compartment is not immediate. The air conditioning system can therefore operate with 100% recirculated air. During this initial period, the process will dehumidify the air without drawing in outside air, thus minimizing the electrical energy consumption of the air conditioning system while simultaneously dehumidifying the air.

[0066] Preferably, the latency time is less than or equal to the period associated with the opening frequency of the shutter(s); for example, the latency time is less than or equal to 0.8 times said period, preferably less than or equal to 0.6 times, and preferably even less than or equal to 0.4 times. The latency time starts when the doors are closed.

[0067] The method includes at least one reference humidity level, namely the initial reference humidity level. However, in preferred embodiments, those skilled in the art will benefit from using additional reference humidity levels chosen or determined to be lower than the initial reference humidity level; for example, an adjusted reference humidity level and one or more intermediate reference humidity levels. As will be seen in detail later, the use of a plurality of reference humidity levels (in addition to the initial reference humidity level) makes it possible to increase the initial reference humidity level and therefore the trigger threshold for opening the air flap(s), while also allowing this trigger threshold to be adapted according to the conditions in which the vehicle is located.

[0068] The choice and / or determination of the value of the reference humidity level(s) is part of the parameters of the process according to the invention.

[0069] According to a preferred embodiment of the method, the tested conditions further include a condition related to the number of people present in the vehicle's passenger compartment and / or a condition related to the change in humidity when the vehicle doors are closed. Preferably, the tested conditions further include both the condition related to the number of people present in the vehicle's passenger compartment and the condition related to the change in humidity when the vehicle doors are closed. The condition relating to the change in humidity level involves measuring the humidity level inside the vehicle's passenger compartment at regular intervals or continuously to determine its change over time when the doors are closed.

[0070] Thus, preferably, the test of the humidity level evolution condition includes at least two measurements of the humidity level in the passenger compartment over a given time interval and their comparison to determine a humidity differential, and the condition is met when the humidity differential determined is less than or equal to a reference differential. For example, the given time interval is between 1 and 120 seconds; preferably, between 5 and 100 seconds or between 10 and 90 seconds; more preferably, between 20 and 70 seconds or between 30 and 50 seconds.

[0071] Alternatively, the test of the humidity level evolution condition in the passenger compartment is performed continuously so as to determine a continuous humidity differential, and the condition is met when the determined humidity differential is less than or equal to a reference differential. A continuous test allows the system to react more quickly when a rapid increase in humidity level is detected.

[0072] Advantageously, the reference differential is between 2 and 5% per minute, preferably between 3 and 4% per minute.

[0073] The condition regarding the evolution of the humidity level makes it possible to assess the fogging time and intervene as quickly as possible. It may or may not be linked to determining the number of occupants in the vehicle, as seen later.

[0074] Indeed, it has been found that a person normally loses approximately 0.05 kg of water per hour through respiration and perspiration. After physical activity, this same person can lose more than 0.5 kg of water per hour. For a vehicle with an interior volume of approximately 2.7 m³, opening the air intake flap(s) of the air conditioning system to allow outside air into the passenger compartment should maximize the fogging time (i.e., the time it takes for the windows to fog up). However, this fogging time can vary from 40 minutes to less than one minute, as shown in Table 1.

[0075] Table 1 summarizes the collected data on fogging time, assuming an indoor temperature of 23-26°C and an initial humidity level of 50%, as a function of the difference with the outdoor temperature and the number of people

[0076] [Tables 1] Normal activities (0.05 kg / h) Sports activities (0.5 kg / h) 1 person 2 people 4 people 1 person 2 people 4 people 0° 40' 20' 10' 4' 2' 1' 5° 30' 15' 7.5' 3' 1.5' 0.8' 10° 25' 12.5' ​​6.3' 2.5' 1.3' 0.6'

[0077] The fogging time varies depending on the number of occupants but also on the amount of water they evacuate. The variation in the humidity level Over time, once the vehicle doors are closed, the system provides an estimate of the condition of the vehicle's occupant(s), for example, whether they have just engaged in physical activity. The detection of the occupants' condition is defined by the rate of change in humidity level after the vehicle doors are closed. During "normal" activity, the increase in humidity level is small. During "intense" activity, the increase in humidity level is rapid.

[0078] The method, the system and the vehicle according to the invention are more robust in that they can adapt to the particularities of each situation.

[0079] According to the invention, the analysis of the evolution of the humidity level makes it possible to adjust the trigger threshold beyond which outside air is injected into the passenger compartment of the vehicle by adjusting the reference humidity level.

[0080] For example, under "normal" conditions with 1 to 4 people in the vehicle, the humidity differential will be small. For instance, if the reference differential is 4% per minute, and the change is measured over a one-minute interval, and the humidity level increases from 50% to 51% after the doors are closed, the resulting humidity differential will be 1% per minute, and therefore lower than the reference differential. The condition is met, and the threshold criterion for triggering the opening of the outside air intake flap(s), namely the initial reference humidity level, can be set to be high because the vehicle is operating under conditions where fogging is prolonged. Thus, an initial reference humidity level of 85% can be the threshold value used to verify the appropriateness of executing the default opening command.The energy savings associated with a trigger threshold of 85% humidity rather than 80% humidity is in the order of 0.1 to 0.25 kW / 100 km.

[0081] Conversely, if "intense" occupant activity is detected, the threshold for triggering the opening of the outside air intake must be lowered because the fogging time is faster. When the condition for humidity level evolution is not met, that is, when the humidity level changes rapidly once the vehicle doors are closed, the process will use a reference humidity level (adjusted or intermediate) lower than the initial reference humidity level as the threshold value for triggering the opening of the flap(s). This allows for earlier opening of the flap(s) or an increase in the opening of the flap(s), and thus anticipates window fogging.

[0082] The process may use a single adjusted reference humidity level or, according to a preferred embodiment, several reference humidity levels modified, namely an adjusted reference humidity level and one or more intermediate reference humidity levels.

[0083] In a preferred embodiment, when the humidity level change condition is not met, the process will use an adjusted reference humidity level to test the humidity level condition. Preferably, when the humidity level change condition is not met, the process will use an adjusted reference humidity level or an intermediate reference humidity level to test the humidity level condition. Advantageously, the adjusted reference humidity level is between 60 and 80%; more preferably between 65 and 75%.

[0084] It is understood that the trigger threshold for opening the shutter(s), based on an initial reference humidity level of 85% in our previous example, can be lowered to a threshold value of 70%. Lowering the threshold value allows for faster action and prevents the windows from fogging up.

[0085] To further refine the threshold for triggering the opening of the flap(s), the method can use several humidity differential values. In a preferred embodiment, when the humidity level change condition is not met, the determined humidity differential is also compared to a critical humidity differential. When the determined humidity differential is greater than or equal to the critical humidity differential, the air intake flap(s) open according to a modified command that is executed when the cabin humidity level is equal to or greater than an adjusted reference humidity level, the adjusted reference humidity level being chosen to be lower than the initial reference humidity level. For example, the critical humidity differential is between 5 and 8% per minute, preferably between 6 and 7% per minute.

[0086] Preferably, when the humidity level change condition is not met, the determined humidity differential is compared to a critical humidity differential, and when the determined humidity differential is less than the critical humidity differential, the air intake flap(s) are opened according to a modified command that is executed when the cabin humidity level is equal to or greater than an intermediate reference humidity level, the intermediate reference humidity level being chosen to be lower than the initial reference humidity level and higher than the adjusted reference humidity level. Advantageously, the intermediate reference humidity level is between 70 and 85%; more preferably between 75 and 82%.

[0087] In one embodiment of the invention, the parameterization of the trigger threshold, taking into account the evolution of the humidity level, may include a reference humidity differential of 4% per minute and a critical humidity differential of 6% per minute;

[0088] when the increase in humidity level is less than 4% per minute, the reference humidity level used is the initial reference humidity level; for example, it is set at 85%;

[0089] when the increase in humidity level is between 4 and 6% per minute, the reference humidity level used is the intermediate reference humidity level; for example, it is set at 80%;

[0090] when the increase in humidity level is greater than 6% per minute, the reference humidity level used is the adjusted reference humidity level; for example, it is set at 70%.

[0091] By allowing air into the vehicle earlier through a lower trigger threshold, the overall volume of air entering the vehicle is increased.

[0092] Determining the evolution of the humidity level inside the vehicle can be enhanced by determining the number of people present in the vehicle. Determining the number of people in the vehicle can also be used to adjust the air exchange rate.

[0093] Indeed, according to a preferred embodiment of the invention, the tested conditions include at least one condition related to the number of people present in the vehicle's passenger compartment, and said condition is met when the number of people in the vehicle is equal to one or less than or equal to a reference number; for example, less than or equal to two.

[0094] The vehicle is preferably equipped with a means for determining the number of people present in the passenger compartment. This means can be of any type; for example, the means for detecting the number of people in the passenger compartment may include one or more means selected from an interior camera, an interior radar, seatbelt detection sensors, pressure sensors located in the seats, and a human-machine interface through which the driver enters the number of occupants in the vehicle.

[0095] This condition allows, among other things, for the optimization of the air exchange rate criteria for the passenger compartment based on the number of people present in the passenger compartment and the volume of said passenger compartment. Indeed, for a given volume, the carbon dioxide content in the passenger compartment will vary depending on the number of occupants in the vehicle; the air exchange rate must therefore be adjusted.

[0096] Choosing a minimum number of occupants present in the vehicle as an execution parameter for the default opening command is one of the parameters of the method according to the invention. For example, it is possible to optimize the method so that the default opening command applies only when the driver is alone in the vehicle (i.e., when the number of occupants in the vehicle is equal to one) or when the driver is alone or accompanied by only one passenger (e.g., the number of occupants in the vehicle is less than or equal to two).

[0097] It is indeed advantageous for the method to be configured to implement the default opening command only when the vehicle contains only one or two occupants, since these are the most common situations and the conditions under which the need for air renewal in the passenger compartment is lowest. When the vehicle is traveling with only one occupant, namely the driver, it is clear that the amount of air required for air renewal in the passenger compartment is minimized compared to the case where four or more people are in the vehicle. The method is remarkable in that it adapts the air renewal rate and / or the amount of outside air entering according to the number of people in the vehicle.

[0098] In one embodiment of the invention, the control for opening the air intake flap(s) is an intermittent opening control, and when the condition regarding the number of people present is not met, the adjusted opening frequency corresponds to the initial frequency divided by a divisor corresponding to the number of people present in the vehicle divided by the reference number. In an example embodiment, if the reference number is 1 and the initial frequency is 75 minutes, when 3 people are present in the vehicle, the method will modify the opening frequency of the flap(s) to use an adjusted frequency of 25 minutes. The air exchange rate will be multiplied by 3, thus increasing the comfort of the vehicle's occupants.In an example implementation, if the reference number is 2 and the initial frequency is 40 minutes, when 3 people are present in the vehicle, the process will modify the opening frequency of the flap(s) to use an adjusted frequency of 27 minutes.

[0099] It is advantageous for the opening duration when implementing an adjusted opening frequency to remain the same as when implementing an initial opening frequency. The opening duration of the shutter(s) is, for example, between 1 and 5 minutes, preferably between 2 and 4 minutes.

[0100] It has been found that optimizing the amount of air entering the vehicle and adjusting the resulting air exchange rate reduces electrical energy consumption, particularly when outside temperatures are low. This is illustrated in [Fig. 1]. Curves A and C are comparative. Curve A illustrates, as a function of outside temperature, the variations in the driving range of a vehicle with the air conditioning system switched off. Curve C is a similar curve but for a vehicle with the air conditioning system switched on. The air conditioning is switched on and a conventional management system is in operation. Curve B is a similar curve but for a vehicle according to the invention with its air conditioning system switched on and implementing the system according to the invention. When the outside temperature is -7°C, the vehicle according to the invention (curve B) benefits from an increased range of approximately 40 km compared to the vehicle in curve C.

[0101] Although described in the context of an application to a hybrid or electric vehicle, the invention can be applied to a vehicle with a thermal engine since a reduction in the electrical energy consumption of the air conditioning system leads to a reduction in fuel consumption.

Claims

1. Demands A method for managing an air conditioning system in a motor vehicle, the vehicle comprising a passenger compartment and doors and being equipped with an electronic control unit configured to control the opening and closing of one or more air intake flaps of the air conditioning system, said method comprising the following steps: perform a relevance review by testing the veracity of several predefined conditions including at least one outside temperature condition and one cabin humidity level condition and execute an opening command for the air intake flap(s) based on the results of the tests performed, such that: when all the tested conditions are met, then a default opening command is executed allowing a given volume of outside air to enter the cabin and / or allowing the air in the cabin to be renewed at a given air renewal rate; when at least one of the tested conditions is not met, then a modified opening command is executed, the modified opening command increasing the volume of outside air entering the vehicle and / or increasing the air renewal rate compared to the default opening command;said test of the outside temperature condition comprising the measurement of the outside temperature of the vehicle and its comparison to a reference temperature; the condition being met when the measured outside temperature is greater than or equal to the reference temperature; and / or said test of the humidity level condition comprising the measurement of the humidity level in the passenger compartment; the condition being met when the measured humidity level is equal to or greater than an initial reference humidity level; said management method is characterized in that the tested conditions further include a condition for the evolution of the humidity level when the vehicle doors are closed; preferably, the test of the humidity level evolution condition includes at least two measurements of the humidity level in the passenger compartment over a given time interval and their comparison to determine a humidity differential, and the condition is filled when the determined humidity differential is less than or equal to a reference differential.

2. The management method according to claim 1, characterized in that when the condition for the evolution of the humidity level is not met, the determined humidity differential is compared to a critical humidity differential and in that when the determined humidity differential is greater than or equal to the critical humidity differential, the opening of the air inlet flap(s) is done according to a modified command which is executed when the humidity level of the passenger compartment is equal to or greater than an adjusted reference humidity level, the adjusted reference humidity level being chosen to be less than the initial reference humidity level.

3. The management method according to any one of claims 1 to 2, characterized in that the tested conditions further include a condition for the number of people present; preferably, the test of the condition for the number of people present includes determining the number of people in the vehicle and comparing it to a reference number, and said condition is met when the number of people in the vehicle is equal to or less than said reference number.

4. The management method according to any one of claims 1 to 3, characterized in that the opening control of the damper(s) is a continuous opening control such that the default opening control sets a continuous opening of the damper(s) according to a given initial degree of opening and the modified opening control(s) sets a continuous opening of the air inlet damper(s) according to an adjusted degree of opening greater than the initial degree of opening; or in that the opening control of the damper(s) is an intermittent opening control such that the default opening control sets an intermittent opening of the damper(s) according to a given initial frequency and the modified opening control(s) sets an intermittent opening of the air inlet damper(s) according to an adjusted opening frequency greater than the initial frequency.

5. The management method according to claims 1, 3 and 4, characterized in that the control for opening the air inlet flap(s) is an intermittent opening command, and in that when the condition of the number of persons present is not met, then the adjusted opening frequency corresponds to the initial frequency divided by a divisor corresponding to the number of persons present in the vehicle divided by the reference number; preferably, the initial frequency corresponds to an opening of the flap(s) in a unit of time chosen to be between 30 and 100 minutes.

6. The management method according to claim 4, characterized in that the opening control of the flap(s) is a continuous opening control and in that the initial degree of opening given corresponds to a partial opening of said air inlet flap(s) which is less than or equal to 70% of the total opening; preferably a partial opening between 40 and 60% of the total opening.

7. The management method according to any one of claims 4 or 6, characterized in that the opening command of the flap(s) is a continuous opening command and in that after the vehicle doors are closed, the opening of the flap(s) is initiated after a latency period of a predetermined duration; preferably, the latency period is between 15 and 30 minutes.

8. A vehicle comprising a passenger compartment and an air conditioning system having at least one air inlet flap that can be opened so that outside air can enter the passenger compartment or that can be closed, the vehicle further comprising an electronic control unit configured to control the opening of the air inlet flap(s) of the air conditioning system, the vehicle is characterized in that it comprises test equipment including a temperature sensor configured to determine the temperature outside the vehicle; a humidity sensor arranged to determine the humidity level inside the passenger compartment and, optionally, a means for determining the number of persons present in the passenger compartment of the vehicle; and in that the electronic control unit is configured to implement the method according to any one of claims 1 to 7 using the data from the test equipment;Preferably, the vehicle is an electric or hybrid vehicle.

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