Air conditioning system and air conditioning control method

Abstract

The objective is to provide an air conditioning system and air conditioning control method that can achieve both the avoidance of hypertension in users and the maintenance of comfort. [Solution] The control unit 3 controls the air conditioning unit 2 based on the user-specific comfort correlation curve and blood pressure table stored in the memory unit 5. Specifically, when the air conditioning unit 2 is operating, if the user's blood pressure table is within a predetermined blood pressure health range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature corresponding to a predetermined range on the line of the user's comfort correlation curve that includes a predetermined optimal value of the comfort index. Furthermore, if the blood pressure table is outside the blood pressure health range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature corresponding to the upper limit of a predetermined comfort tolerance range on the line of the comfort correlation curve.

Description

Technical Field

[0001] The present invention relates to an air conditioning system and an air conditioning control method.

Background Art

[0002] Patent Document 1 discloses a car air conditioner control device that measures a user's heart rate and blood pressure during vehicle operation and controls the temperature inside the vehicle cabin based on the heart rate and blood pressure as an apparatus for controlling the air conditioning inside the vehicle cabin such as an automobile. In this control device, when the user's heart rate is low, the room temperature is increased by a predetermined degree so that the heart rate becomes high, and when the heart rate is high, the room temperature is decreased.

[0003] Also, generally, during human activities, heat is carried away from the body by blood flow, so blood vessels dilate and blood pressure tends to be lower than during rest. However, when the room temperature is low, blood vessels constrict and blood pressure increases. Furthermore, since the elderly generally have a lower heat production amount and higher blood pressure than the young, they tend to be more prone to hypertension. Therefore, the elderly feel more comfortable and safe at a slightly higher room temperature than the young. Thus, in this control device, when the blood pressure is high, the room temperature is increased according to the increase in blood pressure to avoid hypertension.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The above-mentioned car air conditioning control system raises the room temperature by a predetermined rate in response to changes in heart rate and blood pressure. However, in actual use, each user has a different perception of whether a room temperature is comfortable or not, and the degree to which blood pressure changes in response to temperature changes also varies. Therefore, the above-mentioned control system has the problem of not being able to achieve both the avoidance of high blood pressure and the maintenance of comfort.

[0006] This invention has been made in view of the circumstances described above, and aims to provide an air conditioning system and air conditioning control method that can achieve both the avoidance of high blood pressure in the user and the maintenance of comfort. [Means for solving the problem]

[0007] To solve the aforementioned problems, the air conditioning system of the present invention comprises an air conditioning unit that provides air conditioning for a space where a user is present; an identification unit that identifies the user; a temperature sensor that acquires the ambient temperature, which is the temperature in the space; a storage unit that stores a comfort correlation curve relating to the correlation between the ambient temperature and a comfort index relating to comfort at the ambient temperature, and a blood pressure table relating to the correlation between the ambient temperature and blood pressure for each user, and further stores a predetermined comfort tolerance range, which is the range of blood pressure that allows for comfort in the comfort index, and a predetermined blood pressure health range, which is the range of blood pressure that maintains a healthy state; and a control unit that controls the air conditioning unit. The control unit controls the air conditioning unit so that, when the air conditioning unit is in air conditioning operation, if the user's blood pressure table is within the blood pressure health range, the ambient temperature becomes a temperature corresponding to a predetermined range including a predetermined optimal value of the comfort index on the line of the user's comfort correlation curve; and if the blood pressure table is outside the blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature becomes a temperature corresponding to the upper limit of the comfort tolerance range on the line of the comfort correlation curve.

[0008] In this configuration, the control unit controls the air conditioning unit based on the user-specific comfort correlation curve and blood pressure table stored in the memory unit. Specifically, when the air conditioning unit is operating, if the user's blood pressure table is within a predetermined blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature corresponds to a predetermined range on the user's comfort correlation curve that includes a predetermined optimal value of the comfort index. Furthermore, if the blood pressure table is outside the blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature corresponds to a predetermined upper limit of the acceptable comfort range on the comfort correlation curve.

[0009] This allows the control unit to control the air conditioning system to prevent excessively low ambient temperatures that could lead to hypertension. Simultaneously, the control unit evaluates the user's level of comfort at different ambient temperatures using a comfort correlation curve, and controls the air conditioning system to maintain comfort within a comfortable tolerance range. Therefore, it is possible to perform optimal air conditioning control to prevent excessive increases in ambient temperature for each user, thus avoiding hypertension. As a result, it is possible to achieve both the avoidance of hypertension and the maintenance of comfort.

[0010] In the above-described air conditioning system and air conditioning control method, it is preferable that the optimal value is the minimum value within the range of the user's comfort correlation curve.

[0011] With this configuration, the control unit can accurately control the air conditioning unit within the acceptable comfort range.

[0012] In the above-described air conditioning system and air conditioning control method, the comfort index is preferably the rate of human body exergy consumption.

[0013] With this configuration, the control unit can accurately determine the comfort index and control the air conditioning unit with precision.

[0014] In the above-described air conditioning system, the space where the user is located is the passenger compartment of a vehicle, and it is preferable that the system further includes a vehicle speed sensor that acquires the speed of the vehicle, and that the control unit corrects the blood pressure table to increase blood pressure in accordance with the increase in vehicle speed, determines whether the corrected blood pressure table is within the range of healthy blood pressure, and controls the air conditioning unit based on the determination result.

[0015] A user's blood pressure tends to increase with increasing vehicle speed. Therefore, in the above configuration, the control unit corrects the blood pressure table to increase blood pressure in accordance with the increase in vehicle speed, determines whether the corrected blood pressure table is within the healthy blood pressure range, and controls the air conditioning unit based on the determination result. This allows the control unit to accurately determine the blood pressure table corresponding to the increase in vehicle speed and control the air conditioning unit with high precision.

[0016] In the above-described air conditioning system, the space where the user is located is the vehicle's cabin, and it is preferable that the system further includes an acceleration sensor to acquire the vehicle's acceleration, and that the control unit corrects the blood pressure table to increase blood pressure in accordance with the increase in the vehicle's acceleration, determines whether the corrected blood pressure table is within the blood pressure health range, and controls the air conditioning unit based on the determination result.

[0017] A user's blood pressure tends to increase with increasing acceleration during vehicle operation. Therefore, in the above configuration, the control unit corrects the blood pressure table to increase blood pressure in accordance with the increase in vehicle acceleration, determines whether the corrected blood pressure table is within the healthy blood pressure range, and controls the air conditioning unit based on the determination result. This allows the control unit to accurately determine the blood pressure table corresponding to the increase in acceleration and control the air conditioning unit with precision.

[0018] In the above-described air conditioning system, it is preferable to further include a blood pressure sensor that acquires the user's blood pressure, and a blood pressure table generation unit that generates a blood pressure table for each user based on the ambient temperature and the user's blood pressure, and updates the blood pressure table stored in the storage unit.

[0019] With this configuration, a blood pressure table for each user is generated while the user is in the space, and the blood pressure table stored in the memory unit is updated, making it possible to control the air conditioning unit with high precision using the latest blood pressure table.

[0020] In the above-described air conditioning system, it is preferable to further include a comfort correlation curve generation unit that generates a comfort correlation curve for each user based on the ambient temperature and at least one of the humidity, wind speed, and radiant temperature inside the vehicle cabin, and updates the comfort correlation curve stored in the storage unit.

[0021] With this configuration, a comfort correlation curve for each user is generated while the user is in the space, and the comfort correlation curve stored in the memory unit is updated, making it possible to control the air conditioning unit with high precision using the latest comfort correlation curve.

[0022] The air conditioning control method of the present invention is an air conditioning control method using the above-described air conditioning system, characterized in that it includes: a first step of identifying the user by the identification unit; a second step of acquiring the ambient temperature by the temperature sensor; a third step of determining whether the user's blood pressure table stored in the storage unit is within the range of the blood pressure health range; and a fourth step in which, while the air conditioning unit is operating, if the user's blood pressure table is within the range of the blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature becomes a temperature corresponding to a predetermined range including a predetermined optimal value of the comfort index on the line of the user's comfort correlation curve, and if the blood pressure table is outside the range of the blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature becomes a temperature corresponding to the upper limit of the comfort tolerance range on the line of the comfort correlation curve.

[0023] By executing the air conditioning control method configured as described above, the control unit can control the air conditioning unit so that the environmental temperature is not too low and does not cause excessive high blood pressure. Also, at the same time, the control unit also evaluates the degree of user comfort at the environmental temperature using the comfort correlation curve, and controls the air conditioning unit to maintain comfort within the comfort tolerance range. Therefore, it is possible to perform optimal air conditioning control to avoid excessive increase in environmental temperature so that each user does not develop high blood pressure. As a result, it is possible to achieve both the avoidance of high blood pressure and the maintenance of comfort.

Effect of the Invention

[0024] As described above, according to the air conditioning system and the air conditioning control method of the present invention, it is possible to achieve both the avoidance of high blood pressure of the user and the maintenance of comfort.

Brief Description of the Drawings

[0025] [Figure 1] It is a block diagram showing an air conditioning system according to an embodiment of the present invention. [Figure 2] (a) is a graph showing the relationship between the environmental temperature and the comfort index, and shows that there are individual differences in the comfort correlation curve for each user. (b) is a graph showing the relationship between the environmental temperature and blood pressure, and shows that there are individual differences in the blood pressure table for each user. [Figure 3] It is the first half of a flowchart showing the procedure of an air conditioning control method using the air conditioning system of FIG. 1. [Figure 4] It is the second half of a flowchart showing the procedure of an air conditioning control method using the air conditioning system of FIG. 1. [Figure 5] (a) is a graph showing the relationship between the environmental temperature and the comfort index, and shows that the environmental temperature is set so that the comfort index becomes the minimum value corresponding to the optimal value on the comfort correlation curve for each user. (b) is a graph showing the relationship between the environmental temperature and blood pressure, and shows that the blood pressure table for each user is sufficiently low and within the blood pressure healthy range. [Figure 6](a) is a graph showing the relationship between ambient temperature and comfort index, indicating that the ambient temperature should be set so that it lies on the line of the comfort correlation curve for each user, corresponding to the upper limit of the comfort tolerance range. (b) is a graph showing the relationship between ambient temperature and blood pressure, indicating that the blood pressure table for each user is outside the healthy blood pressure range. [Figure 7] This graph shows the relationship between ambient temperature and blood pressure, and illustrates how the blood pressure table is corrected to increase in accordance with the increase in vehicle speed or acceleration. [Figure 8] As a variation of the present invention, here is an explanatory diagram for illustrating stress estimates for correcting a blood pressure table, where (a) is a graph showing the relationship between the k-th heart rate interval and the subsequent k+1-th heart rate interval in a person with low stress, showing that the variability of heart rate intervals is large, and (b) is a graph showing the relationship between the k-th heart rate interval and the subsequent k+1-th heart rate interval in a person with high stress, showing that the variability of heart rate intervals is small. [Modes for carrying out the invention]

[0026] Hereinafter, an air conditioning system and an air conditioning control method according to embodiments of the present invention will be described in detail with reference to the drawings.

[0027] (Air conditioning system configuration) The air conditioning system 1 shown in Figure 1 controls the air conditioning based on each user's degree of comfort with respect to ambient temperature (specifically, the comfort correlation curve LC in Figure 2(a)) and the degree of blood pressure increase in response to changes in ambient temperature (blood pressure table LB in Figure 2(b)), thereby enabling both the avoidance of hypertension and the maintenance of comfort for each user. In this embodiment, the air conditioning system 1 controls the air conditioning of a vehicle cabin as an example of a space where a user is present, but it can also be applied to the air conditioning control of other spaces (for example, theaters or airplane cabins).

[0028] The air conditioning system 1 comprises, as its main components, an air conditioning unit 2 that provides air conditioning for the vehicle compartment where the user is located, a control unit 3 that controls the air conditioning unit 2, an identification unit 4 that identifies the user, a temperature sensor 6 that acquires the ambient temperature, which is the temperature inside the vehicle compartment, and a storage unit 5.

[0029] The air conditioning system 1 of this embodiment further includes a blood pressure sensor 7 and a blood pressure table generation unit 8 for acquiring the user's blood pressure in order to create and update a blood pressure table LB.

[0030] Furthermore, the air conditioning system 1 includes a comfort correlation curve generation unit 9 for creating and updating the comfort correlation curve LC, and also includes a humidity sensor 10, a wind speed sensor 11, and a radiant temperature sensor 12 for obtaining humidity, wind speed, and radiant temperature inside the vehicle cabin. The radiant temperature sensor 12 obtains, for example, the radiant temperature of the body surface of a user sitting in the seat or its vicinity as the radiant temperature.

[0031] Furthermore, the air conditioning system 1 includes a vehicle speed sensor 13 that acquires the vehicle's speed and an acceleration sensor 14 that acquires the vehicle's acceleration.

[0032] The features of the air conditioning system 1 of this embodiment will be described in more detail below.

[0033] The memory unit 5 stores, as unique information for each user, a comfort correlation curve LC relating to the correlation between ambient temperature and a comfort index related to comfort at ambient temperature, and a blood pressure table LB relating to the correlation between ambient temperature and blood pressure, as shown in Figures 2(a) and (b).

[0034] As shown in Figure 2(a), the comfort correlation curve LC is a curve relating to the correlation between ambient temperature and the comfort index, which relates to comfort at that ambient temperature. The comfort correlation curve LC is a unique curve for each user, where the degree of comfort (comfort index) in relation to ambient temperature varies from user to user. As shown by the dashed and dotted lines in the figure, individual differences among users (e.g., age and physique) can cause shifts in the direction of the horizontal axis (ambient temperature) and vertical axis (comfort index) or changes in curvature.

[0035] The comfort correlation curve LC in this embodiment is a downward-convex curve, and its minimum value, i.e., the pole of the curve, is the optimal value at which the user requires the least amount of internal adjustment of thermal energy to maintain comfort. The user can be most comfortable at or near the ambient temperature corresponding to the minimum value (optimal value) of the comfort correlation curve LC.

[0036] Comfort indices are indicators of comfort at ambient temperature, and a typical example is the rate of human exergy consumption. The rate of human exergy consumption is the rate at which all thermal energy released from the human body to the outside (the sum of thermal energy directly released from the body surface into the outside air and thermal energy contained in bodily fluids such as sweat or exhaled breath) is consumed by the human body.

[0037] In addition to the above-mentioned rate of human exergy consumption, SET is also a comfort indicator. * Perceived thermal indices such as the (new standard effective temperature) will also be adopted.

[0038] Comfort indicators such as the rate of human exergy consumption can be determined based on the ambient temperature inside the vehicle where the user is located, along with at least one of the following: humidity inside the vehicle, wind speed, and radiant temperature.

[0039] Therefore, in this embodiment, the comfort correlation curve generation unit 9 generates a comfort correlation curve LC relating to the correlation between ambient temperature and comfort index for each user, based on ambient temperature and at least one of the following: humidity inside the vehicle, wind speed, and radiant temperature (in this embodiment, all of the humidity inside the vehicle, wind speed, and radiant temperature, along with ambient temperature), and updates the comfort correlation curve LC stored in the storage unit 5.

[0040] Furthermore, it is possible to generate a curve that is substantially equivalent to or approximates the comfort correlation curve by using one or two of the following factors in addition to ambient temperature: humidity inside the vehicle, wind speed, and radiant temperature.

[0041] As shown in Figure 2(b), the blood pressure table LB is a straight line relating to the correlation between ambient temperature and blood pressure, and is a downward-sloping line indicating that blood pressure decreases as ambient temperature rises. The blood pressure table LB is a unique straight line for each user that shows the degree of change in blood pressure in relation to ambient temperature for each user, and as shown by the dashed line in the figure, it shifts in the direction of the horizontal axis (ambient temperature) and vertical axis (vertical axis) in the figure due to individual differences in users (e.g., age and body size).

[0042] In this embodiment, the blood pressure table generation unit 8 generates a blood pressure table LB for each user based on the ambient temperature and the user's blood pressure, and updates the blood pressure table LB stored in the storage unit 5.

[0043] Furthermore, the memory unit 5 stores, as data common to all users, a predetermined comfort tolerance range, which is the range within which comfort is acceptable in the comfort index, and a predetermined blood pressure health range, which is the range within which blood pressure maintains a healthy state.

[0044] The comfort tolerance range is determined by sampling the range of comfort in the comfort index when a large number of users feel comfortable, and is defined as the acceptable range of comfort in the comfort index. Therefore, the comfort tolerance range is expressed as a numerical range of a given comfort index, as shown in Figures 5(a) and 6(a).

[0045] Furthermore, the blood pressure health range is determined by sampling the blood pressure range in which each user maintains a healthy state using a large number of users. Therefore, the blood pressure health range is represented by a predetermined numerical range of blood pressure, as shown in Figure 2(b). Looking at Figure 2(b), the position of blood pressure table LB differs for each user, so some blood pressure table LBs have their entire range within the blood pressure health range, while others have part or all of their range outside the blood pressure health range. The position of blood pressure table LB tends to be higher as the user's age increases. When the position of blood pressure table LB is higher, the portion of blood pressure table LB that falls outside the blood pressure health range increases, and the range of ambient temperatures in which the user can maintain a healthy state narrows from lower ambient temperatures. Therefore, for typical elderly people, whose blood pressure table LB position tends to be higher, setting the ambient temperature higher will help them maintain their health.

[0046] In this embodiment, the control unit 3 controls the air conditioning unit 2 during air conditioning operation, as shown in Figure 5(b), so that if a user's blood pressure table LB1 is within the healthy blood pressure range, the ambient temperature becomes a temperature T1 corresponding to a predetermined optimal value of the comfort index on the line of the user's comfort correlation curve LC1, which in this embodiment is a predetermined range including the minimum value P1 of the comfort correlation curve LC1 (for example, a range of ±5% of the minimum value P1).

[0047] In terms of specific operation of the air conditioning unit 2, if the vehicle is cold, such as in winter, and the ambient temperature inside the vehicle is lower than the above temperature T1, the air conditioning unit 2 should operate in heating mode to raise the ambient temperature to T1. On the other hand, if the vehicle is hot, such as in summer, and the ambient temperature inside the vehicle is higher than the above temperature T1, the air conditioning unit 2 should operate in cooling mode to lower the ambient temperature to T1.

[0048] Furthermore, for other users, the blood pressure table LB2 and comfort correlation curve LC2 are located at different positions than the blood pressure table LB1 and comfort correlation curve LC1 described above. In this case, if the blood pressure table LB2 is within the healthy blood pressure range, the control unit 3 should control the air conditioning unit 2 so that the temperature T2 corresponds to a predetermined range including the minimum value P2 of the comfort correlation curve LC2. Therefore, air conditioning control becomes possible so that the ambient temperature T1 and T2 correspond to the minimum values ​​P1 and P2 that are optimal values ​​on the lines of each user's respective comfort correlation curves LC1 and LC2, resulting in a comfortable ambient temperature for each user.

[0049] On the other hand, when the air conditioning unit 2 is operating, as shown in Figure 6(b), if another user's blood pressure table LB11 is outside the healthy blood pressure range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature T13 corresponding to the upper limit P13 of the comfort tolerance range on the line of the comfort correlation curve LC11 for that user. In other words, if the blood pressure table LB11 is outside the healthy blood pressure range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature T13 corresponding to the upper limit P13 of the comfort tolerance range, which is higher than the temperature T11 corresponding to the minimum value P11 of the comfort correlation curve LC11 (i.e., to operate the heating function). In this way, for users such as elderly people with a higher blood pressure table LB11, it becomes possible to control the air conditioning to achieve a higher ambient temperature while maintaining comfort within the comfort tolerance temperature range.

[0050] Furthermore, as shown in Figures 5(a) and 6(a) above, the portion of each user's comfort correlation curve LC1, LC2, and LC11 that includes the optimal minimum values ​​P1, P2, and P11 is always included in the acceptable comfort range. This is because the acceptable comfort range is determined by sampling the range of comfort indices that each user finds comfortable using a large number of users, and moreover, the portion of each user's comfort correlation curve LC1, LC2, and LC11 that includes the optimal minimum values ​​P1, P2, and P11 corresponds to the comfort indices that that user finds comfortable.

[0051] Furthermore, while the vehicle is in motion, the user's blood pressure tends to rise as the vehicle speed increases due to factors such as user anxiety. Therefore, as shown in Figure 7, the control unit 3 of this embodiment can correct the blood pressure table LB21 to increase blood pressure in accordance with the increase in vehicle speed, determine whether the corrected blood pressure table LB22 is within the healthy blood pressure range for the user, and control the air conditioning unit 2 based on the determination result. Here, the correction from blood pressure table LB21 to blood pressure table LB22 in response to the increase in vehicle speed may be a shift correction that uniformly adds a predetermined blood pressure increase amount across the entire range and shifts it in parallel, or a correction that changes the inclination of blood pressure table LB21, or a combination of these corrections.

[0052] Similar to the case of increasing vehicle speed described above, as the vehicle's acceleration increases while the vehicle is in motion, the user's blood pressure tends to rise due to factors such as tension. Therefore, the control unit 3 of this embodiment can correct the blood pressure table LB21 to increase blood pressure in accordance with the increase in acceleration, as shown in Figure 7 above, and determine whether the corrected blood pressure table LB22 is within the user's blood pressure health range. Based on the determination result, it is also possible to control the air conditioning unit 2. Here, the correction from blood pressure table LB21 to blood pressure table LB22 in response to the increase in acceleration may be a shift correction that uniformly adds a predetermined blood pressure increase to the entire range and shifts it in parallel, or a correction that changes the inclination of blood pressure table LB21, or a combination of these corrections.

[0053] (Air conditioning control method of this embodiment) The air conditioning control method using the above-described air conditioning system 1 is basically characterized by including the following steps 1 to 4.

[0054] (First step) The user is identified by the identification unit 4. (Second step) The ambient temperature is obtained by the temperature sensor 6. (Third step) It is determined whether the user's blood pressure table LB stored in the memory unit 5 is within the healthy blood pressure range. (Fourth step) When the air conditioning unit 2 is operating, if the user's blood pressure table is within the healthy blood pressure range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature is a temperature corresponding to a predetermined range on the line of the user's comfort correlation curve that includes a predetermined optimal value of the comfort index. If the blood pressure table is outside the healthy blood pressure range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature is a temperature corresponding to the upper limit of the acceptable comfort range on the line of the comfort correlation curve.

[0055] Therefore, when actually implementing the air conditioning control method using the air conditioning system 1 in Figure 1, it is possible to follow a procedure similar to the series of flowcharts in Figures 3 and 4, including the first to fourth steps described above.

[0056] First, in step S1 of Figure 3, the identification unit 4 identifies the user (first step). The identification unit 4 identifies the user by, for example, information entered by the user (such as username or user-specific number), facial recognition, fingerprint recognition, or voice recognition.

[0057] Next, in step S2, the control unit 3 determines whether the air conditioning is running. If yes, the process proceeds to step S3. In step S3, the temperature sensor 6 obtains the ambient temperature inside the vehicle (second step).

[0058] Next, in step S4, the control unit 3 determines whether the storage unit 5 contains the identified user's blood pressure table LB and comfort correlation curve LC. If yes, the process proceeds to step S9 in Figure 4.

[0059] If step S4 is No, then step S5 is performed to acquire blood pressure using the blood pressure sensor 7, step S6 is performed to generate blood pressure table LB using the blood pressure table generation unit 8, step S7 is performed to acquire humidity, wind speed, and radiant temperature inside the vehicle using the humidity sensor 10, wind speed sensor 11, and radiant temperature sensor 12, and step S8 is performed to generate a comfort correlation curve using the comfort correlation curve generation unit 9, and then the process returns to step S4.

[0060] Next, in step S9 of Figure 4, the control unit 3 determines whether the blood pressure table LB is within the healthy blood pressure range (third step).

[0061] If step S9 is Yes (i.e., the blood pressure table LB1 is within the blood pressure health range as shown in Figure 5(b)), the process proceeds to step S10, in which the control unit 3 controls the air conditioning unit 2 so that the ambient temperature shown in Figure 5(a) becomes the temperature T1 or a temperature near the optimal value (lower limit P1) of the user comfort correlation curve LC1 (one of the controls in the fourth step).

[0062] If step S9 is No (i.e., the blood pressure table LB11 is outside the blood pressure health range as shown in Figure 6(b)), the process proceeds to step S11, where the control unit 3 controls the air conditioning unit 2 so that the ambient temperature is at or near the temperature corresponding to the upper limit P13 of the comfort tolerance range on the line of the user's comfort correlation curve LC11 (control of the other step of the fourth step).

[0063] After step S10 or step S11 described above, the blood pressure table LB is updated by the blood pressure table generation unit 8 in step S12, and the comfort correlation curve LC is updated by the comfort correlation curve generation unit 9 in step S13, after which the series of air conditioning control is terminated.

[0064] The updating of the blood pressure table LB in step S12 and the updating of the comfort correlation curve LC in step S13 may be performed each time for the series of air conditioning control shown in Figures 3-4, or it may be performed periodically at regular intervals.

[0065] (Features of this embodiment)

[0066] (1) As described above, the air conditioning system 1 of this embodiment comprises an air conditioning unit 2, an identification unit 4 for identifying a user, a temperature sensor 6 for acquiring ambient temperature, a storage unit 5 for storing a comfort correlation curve LC and a blood pressure table LB for each user, as well as a predetermined comfort tolerance range and a predetermined blood pressure health range, and a control unit 3 for controlling the air conditioning unit 2.

[0067] When the air conditioning unit 2 is operating, if the user's blood pressure table LB1 is within the healthy blood pressure range as shown in Figure 5(b), the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature T1 corresponding to a predetermined range on the line of the user's comfort correlation curve LC1 that includes a predetermined optimal value of the comfort index (in the above embodiment, the minimum value P1 of the comfort correlation curve LC1 in Figure 5(a)). If the blood pressure table LB11 is outside the healthy blood pressure range as shown in Figure 6(b), the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature T13 corresponding to the upper limit P13 of the acceptable comfort range on the line of the comfort correlation curve LC11 in Figure 6(a).

[0068] As described above, the control unit 3 controls the air conditioning unit 2 based on the user-specific comfort correlation curve LC and blood pressure table LB stored in the memory unit 5. This allows the control unit 3 to control the air conditioning unit 2 so that the ambient temperature is not too low, which would lead to excessive hypertension. At the same time, the control unit 3 also evaluates the user's level of comfort at ambient temperature using the comfort correlation curve LC and controls the air conditioning unit 2 to maintain comfort within the acceptable comfort range. Therefore, it is possible to perform optimal air conditioning control to avoid excessive increases in ambient temperature for each user to prevent hypertension. As a result, it is possible to achieve both the avoidance of hypertension and the maintenance of comfort.

[0069] (2) In the air conditioning system 1 of this embodiment, the above-mentioned optimal value is the minimum value P1 within the range of the user's comfort tolerance curve LC. As a result, the control unit 3 can accurately control the air conditioning unit 2 within the range of the comfort tolerance.

[0070] (3) In the air conditioning system 1 of this embodiment, the comfort index is the rate of human body exergy consumption. This allows the control unit 3 to accurately determine the comfort index and control the air conditioning unit 2 with precision.

[0071] (4) In the air conditioning system 1 of this embodiment, the passenger compartment where the user is located is the passenger compartment of the vehicle. The air conditioning system 1 is equipped with a vehicle speed sensor 13 that acquires the vehicle speed. As shown in Figure 7, the control unit 3 corrects the blood pressure table LB21 to increase blood pressure in accordance with the increase in vehicle speed, determines whether the corrected blood pressure table LB22 is within the healthy blood pressure range, and controls the air conditioning unit 2 based on the determination result.

[0072] The user's blood pressure tends to increase with increasing vehicle speed. Therefore, as described above, the control unit 3 corrects the blood pressure table LB21 to increase blood pressure in accordance with the increase in vehicle speed, determines whether the corrected blood pressure table LB22 is within the healthy blood pressure range, and controls the air conditioning unit 2 based on the determination result. In this way, the control unit 3 can accurately determine the blood pressure table LB22 corresponding to the increase in vehicle speed and control the air conditioning unit 2 with high precision.

[0073] (5) The air conditioning system 1 of this embodiment includes an acceleration sensor 14 that acquires the acceleration of the vehicle. As shown in Figure 7, the control unit 3 corrects the blood pressure table LB21 to increase blood pressure in accordance with the increase in the vehicle's acceleration, determines whether the corrected blood pressure table LB22 is within the healthy blood pressure range, and controls the air conditioning unit 2 based on the determination result.

[0074] A user's blood pressure tends to rise as the vehicle's acceleration increases. Therefore, as described above, the control unit 3 corrects the blood pressure table LB21 to increase blood pressure in accordance with the increase in the vehicle's acceleration, determines whether the corrected blood pressure table LB22 is within the healthy blood pressure range, and controls the air conditioning unit 2 based on the determination result. This allows the control unit 3 to accurately determine the blood pressure table LB22 corresponding to the increase in acceleration and control the air conditioning unit 2 with high precision.

[0075] (6) The air conditioning system 1 of this embodiment includes a blood pressure sensor 7 that acquires the user's blood pressure, and a blood pressure table generation unit 8 that generates a blood pressure table LB for each user based on the ambient temperature and the user's blood pressure, and updates the blood pressure table LB stored in the storage unit 5.

[0076] With this configuration, a blood pressure table LB for each user is generated while the user is in the vehicle compartment, and the blood pressure table LB stored in the storage unit 5 is updated, making it possible to control the air conditioning unit 2 with high accuracy using the latest blood pressure table LB.

[0077] In this embodiment, the air conditioning system 1 is equipped with a blood pressure sensor 7 and a blood pressure table generation unit 8. However, in the present invention, it is sufficient to have a storage unit 5 that stores the blood pressure table LB, so the blood pressure sensor 7 and the blood pressure table generation unit 8 are not necessarily essential components.

[0078] For example, a blood pressure table LB for each user may be generated while riding in another vehicle, and the data from that blood pressure table LB may be stored in the storage unit 5 of the air conditioning system 1 of the next vehicle the user is to ride. Alternatively, if the storage unit 5 that stores the blood pressure table LB is located in a data center connected to the internet by each vehicle's air conditioning system, the blood pressure table LB and the storage unit 5 that stores it can be used in common by each vehicle.

[0079] (7) The air conditioning system 1 of this embodiment includes a comfort correlation curve generation unit 9 that generates a comfort correlation curve LC for each user based on ambient temperature and at least one of the following (in this embodiment, ambient temperature along with humidity, wind speed, and radiant temperature inside the vehicle): ambient temperature, humidity inside the vehicle, wind speed, and radiant temperature, and updates the comfort correlation curve LC stored in the storage unit 5.

[0080] With this configuration, a comfort correlation curve LC for each user is generated while the user is in the vehicle compartment, and the comfort correlation curve LC stored in the memory unit 5 is updated, making it possible to accurately control the air conditioning unit 2 using the latest comfort correlation curve LC.

[0081] In this embodiment, the air conditioning system 1 is equipped with a comfort correlation curve generation unit 9. However, in the present invention, it is sufficient to have a storage unit 5 that stores the comfort correlation curve LC, so the comfort correlation curve generation unit 9 is not necessarily an essential component. For example, as with the blood pressure table LB described above, the comfort correlation curve LC may be generated in other vehicles, or the storage unit 5 that stores the comfort correlation curve LC may be located in a data center and used in common by each vehicle connected to the data center and the Internet.

[0082] (8) The air conditioning control method using the air conditioning system 1 of this embodiment is characterized by including a first step of identifying a user with an identification unit 4, a second step of acquiring the ambient temperature with a temperature sensor 6, a third step of determining whether the user's blood pressure table LB stored in the storage unit 5 is within the range of a healthy blood pressure range, and a fourth step in which, while the air conditioning unit 2 is operating, the control unit 3 controls the air conditioning unit 2 so that if the user's blood pressure table LB is within the range of a healthy blood pressure range, the ambient temperature becomes a temperature corresponding to a predetermined range on the line of the user's comfort correlation curve LC that includes a predetermined optimal value of the comfort index (in this embodiment, the minimum value of the comfort correlation curve LC), and if the blood pressure table LB is outside the range of a healthy blood pressure range, the control unit 3 controls the air conditioning unit 2 so that the ambient temperature becomes a temperature corresponding to the upper limit of the acceptable comfort range on the line of the comfort correlation curve LC.

[0083] By including the first to fourth steps described above, the air conditioning control method enables the control unit 3 to control the air conditioning unit 2 so that the ambient temperature is not too low, preventing excessive hypertension. Simultaneously, the control unit 3 evaluates the user's level of comfort at ambient temperature using the comfort correlation curve LC, and controls the air conditioning unit 2 to maintain comfort within the acceptable comfort range. This makes it possible to perform optimal air conditioning control to avoid excessive increases in ambient temperature for each user, thus preventing hypertension. As a result, both avoiding hypertension and maintaining comfort can be achieved.

[0084] (modified version) In the above embodiment, the blood pressure table LB is corrected so that blood pressure increases in response to an increase in vehicle speed and acceleration, but the present invention is not limited thereto. As a variation of the present invention, the blood pressure table LB may be corrected so that blood pressure increases in response to an increase in the stress estimate.

[0085] Stress levels can be estimated using the magnitude of heart rate variability (L / T) as shown in Figures 8(a) and (b). Figures 8(a) and (b) are quoted from Fig. 3 of the paper "Research on a method for evaluating mental stress using heart rate variability," Life Support Vol. 22 No. 3, 2010, Life Support Society.

[0086] In Figure 8, (a) is a graph showing the relationship between the k-th heart rate interval and the subsequent k+1-th heart rate interval in people with low stress, and it shows that there is a large variation in heart rate intervals. (b) is a graph similar to (a) above, but for people with high stress.

[0087] In the graph in Figure 8(a), the variability of the points showing the correlation between the k-th and k+1-th heart rate intervals is large in people with low stress, and the ratio L1 / T1 (length to width T1 of the point distribution) is large. In contrast, in the graph in Figure 8(b), the variability of the points showing the correlation between the k-th and k+1-th heart rate intervals is small in people with high stress, and the ratio L2 / T2 (length to width T2 of the point distribution) is small.

[0088] The ratios L1 / T1 and L2 / T2 are calculated as stress estimates, and if these ratios are below a certain magnitude, the control unit 3 determines that the user is under high stress and corrects the blood pressure table LB in a direction that increases blood pressure. [Explanation of symbols]

[0089] 1. Air conditioning system 2. Air Conditioning Unit 3. Control Unit 4. Identification Unit 5 Storage section 6. Temperature sensor 7. Blood pressure sensor 8. Blood pressure table generation unit 9. Comfort Index Generation Unit 10 Humidity Sensor 11. Wind speed sensor 12. Radiation temperature sensor 13. Vehicle speed sensor 14. Accelerometer

Claims

1. The air conditioning unit provides air conditioning for the space where the user is located, The user identification unit, A temperature sensor that acquires the ambient temperature, which is the temperature within the aforementioned space, A storage unit that stores, for each user, a comfort correlation curve relating to the correlation between the ambient temperature and a comfort index relating to comfort at the ambient temperature, and a blood pressure table relating to the correlation between the ambient temperature and blood pressure, and further stores a predetermined comfort tolerance range which is the range in which comfort is acceptable in the comfort index, and a predetermined blood pressure health range which is the range in which blood pressure maintains a healthy state. Control unit for controlling the air conditioning unit and Equipped with, The control unit controls the air conditioning unit during air conditioning operation so that, if the user's blood pressure table is within the healthy blood pressure range, the ambient temperature becomes a temperature corresponding to a predetermined range including a predetermined optimal value of the comfort index on the line of the user's comfort correlation curve; and if the blood pressure table is outside the healthy blood pressure range, the control unit controls the air conditioning unit so that the ambient temperature becomes a temperature corresponding to the upper limit of the acceptable comfort range on the line of the comfort correlation curve. An air conditioning system characterized by the following features.

2. In the air conditioning system according to claim 1, The aforementioned optimal value is the minimum value within the acceptable range of comfort among the user's comfort correlation curves. An air conditioning system characterized by the following features.

3. In the air conditioning system according to claim 1 or 2, The aforementioned comfort index is the rate at which human body exergy is consumed. An air conditioning system characterized by the following features.

4. In the air conditioning system according to claim 1 or 2, The space where the user resides is the vehicle's passenger compartment, The vehicle further includes a vehicle speed sensor that acquires the speed of the aforementioned vehicle. The control unit corrects the blood pressure table to increase blood pressure in accordance with the increase in vehicle speed, determines whether the corrected blood pressure table is within the blood pressure health range, and controls the air conditioning unit based on the determination result. An air conditioning system characterized by the following features.

5. In the air conditioning system according to claim 1 or 2, The space where the user resides is the vehicle's passenger compartment, The vehicle is further equipped with an acceleration sensor that acquires the acceleration of the vehicle. The control unit corrects the blood pressure table to increase blood pressure in accordance with the increase in vehicle acceleration, determines whether the corrected blood pressure table is within the blood pressure health range, and controls the air conditioning unit based on the determination result. An air conditioning system characterized by the following features.

6. In the air conditioning system according to claim 1 or 2, A blood pressure sensor that acquires the user's blood pressure, A blood pressure table generation unit generates a blood pressure table for each user based on the ambient temperature and the user's blood pressure, and updates the blood pressure table stored in the storage unit. Furthermore, An air conditioning system characterized by the following features.

7. In the air conditioning system according to claim 1 or 2, The system further includes a comfort correlation curve generation unit that generates a comfort correlation curve for each user based on the ambient temperature and at least one of the humidity, wind speed, and radiant temperature inside the vehicle, and updates the comfort correlation curve stored in the storage unit. An air conditioning system characterized by the following features.

8. In an air conditioning control method using the air conditioning system described in claim 1 or 2, The first step is to identify the user using the identification unit, A second step involves acquiring the ambient temperature using the temperature sensor, A third step of determining whether the user's blood pressure table stored in the storage unit is within the blood pressure healthy range, A fourth step in which, while the air conditioning unit is operating, if the user's blood pressure table is within the blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature becomes a temperature corresponding to a predetermined range including a predetermined optimal value of the comfort index on the line of the user's comfort correlation curve, and if the blood pressure table is outside the blood pressure health range, the control unit controls the air conditioning unit so that the ambient temperature becomes a temperature corresponding to the upper limit of the comfort tolerance range on the line of the comfort correlation curve, An air conditioning control method characterized by including the following.

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