THERMAL MANAGEMENT SYSTEM FOR A MOTOR-VEHICLE PASSENGER COMPARTMENT

Abstract

The invention relates to a thermal management system for a motor-vehicle passenger compartment, this system comprising a processing unit arranged to: —acquire: —a datum (BA) representative of the respiratory amplitude of the passenger,—and/or a datum (BR) representative of the respiratory rhythm of the passenger, —a datum (HR) representative of the cardiac rhythm of the passenger, —optionally a datum on the age of the passenger, —optionally a time-related datum (T) that is representative of the moment during the day, the time of day for example, —determining a datum (MET) representative of the metabolic activity of the passage on the basis of the aforementioned data, —preferably then determining a value of a thermal-comfort index (PMV) associated with the passenger in the passenger compartment on the basis of the datum (MET) representative of the metabolic activity of the passenger.

Claims

1. A thermal management system for a motor vehicle interior, the system comprising: a processing unit arranged for acquiring: a datum representative of the passenger's respiratory amplitude, a datum representative of the passenger's respiratory rate, a datum representative of the passenger's heart rate, optionally, a datum on the passenger's age, optionally, a datum on the time that is representative of the moment during the day, for example the hour of the day, determining a datum representative of the passenger's metabolic activity on the basis of the aforesaid data, proceeding to determine a value of a thermal comfort index associated with the passenger in the interior, on the basis of the datum representative of the passenger's metabolic activity.

2. The system as claimed in claim 1, wherein the metabolic activity is also determined on the basis of the passenger's sex.

3. The system as claimed in claim 1, wherein the metabolic activity is also determined on the basis of the passenger's body mass index.

4. The system as claimed in claim 1, wherein the system comprises a sensor, of either the contact or contactless type, for supplying the datum on the heart rate.

5. The system as claimed in claim 1, wherein the system comprises a sensor, of either the contact or contactless type, for supplying the datum on the respiratory rate and/or the respiratory amplitude.

6. The system as claimed in claim 1, wherein the system is arranged for determining the sex and/or the age of the passenger, these data being automatically identified by a recognition algorithm, using one or more frontal cameras and a trained model, or data that are input by the passenger, in a set of profiles.

7. The system as claimed in claim 1, wherein the system is arranged for determining the weight and/or the height of the passenger, these data being automatically identified by a recognition algorithm, using one or more dome cameras and a trained model, or notably, data that are input by the passenger, in a set of profiles.

8. The system as claimed in claim 1, wherein the system is arranged so that the metabolism model can be adjusted, on the basis of the user's profile, for the region or for the make or model of vehicle.

9. A method of thermal management for a motor vehicle interior, the method comprising: acquiring: a datum representative of the passenger's respiratory amplitude, a datum representative of the passenger's respiratory rate, a datum representative of the passenger's heart rate, a datum on the passenger's age, a datum on the time that is representative of the moment during the day, determining a datum representative of the passenger's metabolic activity on the basis of the aforesaid data; and proceeding to determine a value of a thermal comfort index associated with the passenger in the interior, on the basis of the datum representative of the passenger's metabolic activity.

10. The method as claimed in claim 9, used for one of the following cases of utilization: managing the passenger's comfort in summer immediately after running on foot, managing the comfort of a passenger having a high body mass index, managing the comfort of the passenger immediately after reaction to a stressful situation, for example a risk of accident, managing comfort after lunchtime, managing the thermal comfort of men and women differently, managing the thermal comfort of young and old persons differently.

Description

[0116] The invention will be better understood and other details, features and advantages of the invention will become apparent on reading the following description, which is given by way of non-limiting example with reference to the appended drawings, in which:

[0117] FIG. 1 shows, in a schematic and partial manner, a thermal system according to the invention,

[0118] FIG. 2 shows steps in the method of managing thermal comfort in the system of FIG. 1,

[0119] FIG. 3 shows the different areas of the passenger involved in the method of FIG. 2.

[0120] FIG. 4 shows a processing system for embodiments disclosed herein.

[0121] FIG. 1 shows a thermal management system 1 for a motor vehicle interior, the system comprising a processing unit 2 arranged for: [0122] acquiring a first datum (Clo) representative of the clothing level of a passenger in the interior, [0123] acquiring a second datum (MET) representative of the passenger's metabolic activity, [0124] acquiring a third datum representative of the thermal environment of the passenger in the interior, [0125] determining a value of a thermal comfort index (PMV) associated with the passenger in the interior on the basis of the three data thus acquired.

[0126] The system comprises a plurality of sensors arranged to measure a plurality of parameters serving to determine the first, second and third data.

[0127] These sensors comprise: [0128] a DMS camera 3 arranged for observing a passenger in the interior, [0129] an infrared dome 4 formed by a wide angle infrared camera placed on a ceiling of the interior, for measuring the temperature of the walls and windows of the interior, [0130] a sun sensor 5, [0131] an air temperature sensor 6 at the outlet of an air conditioning unit or of the HVAC 10, [0132] a sensor 7 of the current air temperature in the interior.

[0133] The system 1 is arranged to measure a parameter serving to determine the third datum representative of the thermal environment of the passenger in the interior, this parameter being related to the state of the air-conditioning device, and notably to the power of a blower of the air-conditioning device or the distribution of conditioned air from the air-conditioning device.

[0134] The first datum (Clo) representative of the clothing level of the passenger in the interior corresponds to a measured clothing insulation of the clothes worn by the passenger.

[0135] To this end, the system 1 is arranged to process an image taken by the camera 3 and to, from this image, determine the type of clothes (T-shirt and/or shirt and/or pullover and/or overcoat and/or scarf and/or hat) worn by the passenger notably via image recognition, the system 1 furthermore being arranged to determine clothing insulation from the type of clothes thus measured.

[0136] The second datum (MET) representative of the metabolic activity of the passenger depends on the heart rate HR of the passenger, which is notably measured by the camera 3, as may be seen in FIG. 3. This camera 3 is arranged to observe changes in the color of the face of the passenger due to the movement of blood under the skin of the face, and the system measures heart rate based on these images.

[0137] The second datum (MET) representative of the metabolic activity of the passenger is dependent on a physical characteristic of the passenger, which is measured by the camera 6 with a view to determining, by image processing, physical characteristics PC of the passenger, notably his sex, age, size and volume, and indirectly his weight.

[0138] The second datum MET representative of the metabolic activity of the passenger corresponds to a thermal power per unit area PS produced by the passenger, which is deduced using the datum PC.

[0139] A plurality of data (MET) representative of the metabolic activity of the passenger are used.

[0140] The system 1 is arranged to, from the temperatures of the walls and/or window, which are measured by the infrared dome 4, compute the radiative temperature of a plurality of parts of the body of the passenger, such as his head Z1, chest Z2, back Z3, legs Z4, feet Z5, arms Z6 and hands Z7, as shown in FIG. 3.

[0141] The system 1 is arranged to estimate the temperature of the air making contact with a part of the body of the passenger, and notably a plurality of parts of the body of the passenger, notably his head, chest, back, legs, calves, feet, and/or arms, notably based on the power of an air blower and/or of the distribution of the HVAC and/or of the temperature of the blown air and the temperature of the interior, notably on the basis of charts.

[0142] The system 1 is arranged, on the basis of the HVAC distribution and/or of the power of the air blower, to estimate, notably using charts, the speed of the air making contact with one part or a plurality of parts of the body of the passenger.

[0143] These temperatures and/or speeds TV are used to compute the third datum representative of the thermal environment of the passenger in the interior.

[0144] The system 1 is arranged to estimate the total thermal power (P_tot_theoritical) exchanged by the passenger with his environment by estimating the thermal power exchanged by each part of his body, notably his head, chest, back, legs, calves, feet and arms. This total exchanged thermal power (P_tot_theoritical) is dependent on the data Clo, Met and PS.

[0145] Specifically, the exchanged powers are dependent on the local air speed, on the local air temperature, on the local radiative temperature, on the surface area of the passengers, on the clothing level (Clo) of the passenger, and on the second datum (MET) representative of the metabolic activity of the passenger.

[0146] The system 1 is arranged to compare the total thermal power (P_tot_theoritical) exchanged with the environment with the theoretical power generated by the metabolism of the passengers, and, by multiplying this power difference by a coefficient, to determine a value of the thermal comfort index (PMV).

[0147] According to an aspect of the invention, this model can then be used to estimate the instantaneous comfort of the passengers. Set points may also be defined for the thermal actuators in order to ensure passenger comfort. Adjustment of the thermal system is thus personalized.

[0148] The method is able to take into account heat exchange by respiration, sweating and perspiration, which depends on the ambient humidity and temperature and on metabolism, to estimate a comfort index.

[0149] Metabolic activity is determined depending on the date and/or time, sex, age and other personal characteristics of the passenger, and on the datum or knowledge of their current or previous activities.

[0150] In the example illustrated in FIG. 4, the thermal management system comprises a processing unit 100 arranged for: [0151] acquiring: [0152] a datum (BA) representative of the passenger's respiratory amplitude, [0153] a datum (BR) representative of the passenger's respiratory rate, [0154] a datum (HR) representative of the passenger's heart rate, [0155] optionally, a datum on the passenger's age, [0156] optionally, a datum (T) on the time that is representative of the moment during the day, for example the hour of the day, [0157] determining a datum (MET) representative of the passenger's metabolic activity on the basis of the aforesaid data, [0158] preferably, proceeding to determine a value of a thermal comfort index (PMV) associated with the passenger in the interior, on the basis of the datum (MET) representative of the passenger's metabolic activity.

[0159] The metabolic activity (MET) is also determined on the basis of the passenger's sex.

[0160] The metabolic activity (MET) is also determined on the basis of the passenger's body mass index (BMI), if known.

[0161] The system comprises a sensor, of either the contact or contactless type, for supplying the datum on the heart rate.

[0162] This sensor may be a sensor arranged for being worn by the passenger, for example a watch.

[0163] The system comprises a sensor, of either the contact or contactless type, for supplying the datum on the respiratory rate and/or the respiratory amplitude.

[0164] This sensor may be a sensor arranged for being worn by the passenger, for example a watch.

[0165] According to an aspect of the invention, the system is arranged for determining the sex and/or the age of the passenger, these data preferably being automatically identified by a recognition algorithm, preferably using one or more frontal cameras and a trained model, or, notably, data that are input by the passenger, preferably in a set of profiles.

[0166] According to an aspect of the invention, the system is arranged for determining the weight and/or the height of the passenger, these data preferably being automatically identified by a recognition algorithm, preferably using one or more dome cameras and a trained model, or, notably, data that are input by the passenger, preferably in a set of profiles.

[0167] The equations for calculating the value of MET may be of four types: on the one hand, an equation for men and an equation for women, and, on the other hand, an equation for situations with a low heart rate (HR<transition HR) and an equation for situations with a high heart rate (HR>transition HR), the “transition HR” between the two equations depending on physiological parameters specific to each passenger (sex, age and BMI if known).

[0168] These equations may be of the polynomial type.

[0169] The equation may, for example, be written as follows:

MET=a1×(HR).sup.a2+b1×(BR).sup.b2+c1×(BA).sup.c2+d1×(Age).sup.d2+e1×(T).sup.e2

[0170] The coefficients a1, b1, c1, d1 and e1, and a2, b2, c2, d2 and e2, are a function of the gender (male or female) and of the range of heart rate (lower than or higher than the transition HR).

[0171] If BA is unknown, a replacement equation may be used, in which only BR is active, with a dedicated coefficient and exponent bc1 and bc2:

MET=a1×(HR).sup.a2+bc1×(BR).sup.bc2+d1×(Age).sup.d2+e1×(T).sup.e2

[0172] If “Age” and/or “T” are unknown, a constant “de” may be used in place of one or both of the omitted terms:

MET=a1×(HR).sup.a2+b1×(BR).sup.b2+c1×(BA).sup.c2+de

[0173] The equation makes use of the following data: [0174] a datum (BA) representative of the passenger's respiratory amplitude, [0175] a datum (BR) representative of the passenger's respiratory rate, [0176] a datum (HR) representative of the passenger's heart rate, [0177] a datum (T) on the time that is representative of the moment during the day, for example the hour of the day.

[0178] The datum MET found in this way may then be used in the system described in the embodiment of FIGS. 1 and 2, for determining the value PMV.