Automatic control device

Abstract

To obtain an automatic control device capable of adjusting a state amount of an indoor airborne substances to an amount intended by a user even if detection sensitivity of a state amount detection section has deteriorated over time.SOLUTION: An automatic control device 10 is the automatic control device 10 that controls a state amount adjustment machine for adjusting a state amount of an airborne substance in indoor air. The automatic control device 10 includes: a state amount detection section that detects and outputs a state amount of an indoor airborne substance; and a control section 2 that performs feedback control of the state amount adjustment mechanism on the basis of output from the state amount detection section so that the output from the state amount detection section becomes a target value or lower. The control section 2 calculates a deterioration amount of detection sensitivity over time of the state amount detection section on the basis of an output value from the state amount detection section and a past output value from the state amount detection section, and adjusts the target value on the basis of the deterioration amount.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an automatic control device for controlling a machine having a function for adjusting the state of indoor air. [Background technology]

[0002] In an automatic control device for a ventilation device having a function of adjusting the quality of indoor air, a state quantity detection unit detects the indoor odor concentration or state quantity of fine particulate matter, etc., and controls the ventilation device so that the state quantity detected by the state quantity detection unit becomes a target value. Fine particulate matter is also called PM (Particulate Matter) 2.5. When the indoor air becomes polluted more than the target value due to, for example, cigarette smoke, the ventilation device starts operating, exhausts the polluted air inside the room to the outside, introduces fresh outside air, and ventilates until the indoor air reaches a preset cleanliness level.

[0003] The state quantity detection unit in the automatic control device may have a heat source such as a heater resistor mounted therein in order to accurately detect state quantities such as odor concentration in the room. The heat source plays a role in keeping the state quantity detection unit at a temperature suitable for detecting state quantities such as odor concentration in the room, and in drawing indoor air into the state quantity detection unit by generating an updraft due to the heat generated by the heat source.

[0004] However, immediately after the start of energizing the heat source, the temperature inside the state quantity detection unit and the heat source rises rapidly, causing the substances inside the state quantity detection unit and attached to the heat source to be released all at once. As a result, the output value of the state quantity detection unit increases sharply temporarily as it detects the substances released all at once.

[0005] Therefore, automatic control devices often have a waiting period for stabilization of the output value of the state quantity detection unit, during which the output value of the state quantity detection unit is not used for feedback control of the ventilation device, which is the controlled object, for a predetermined time after starting to supply electricity to the heat source of the state quantity detection unit.

[0006] Patent Document 1 describes an automatic control device that controls a ventilation device equipped with a function for adjusting state quantities such as gas concentration in a specific space, and feedback controls the blower so that the output value of a miscellaneous gas sensor that detects the state quantities in the same space becomes a set target value. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-310480 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the automatic control device described in the above Patent Document 1 has a problem that when the detection sensitivity of the miscellaneous gas sensor decreases due to aging of the miscellaneous gas sensor, a state occurs in which the output value of the miscellaneous gas sensor does not exceed the target value even though the air in the room is polluted, the operation time of the blower is shortened, and the room cannot be sufficiently ventilated. When the room cannot be sufficiently ventilated, the air in the room is polluted and the user feels uncomfortable.

[0009] The present disclosure has been made in consideration of the above, and aims to obtain an automatic control device that can adjust the state quantity of a substance in the air in a room to the amount expected by a user, even if the detection sensitivity of the state quantity detection unit deteriorates over time. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, an automatic control device according to the present disclosure is an automatic control device that controls a state quantity adjustment machine that adjusts the state quantities of airborne substances in indoor air. The automatic control device includes a state quantity detection unit that detects and outputs the state quantities of airborne substances in the room, and a control unit that feedback controls the state quantity adjustment machine based on the output of the state quantity detection unit so that the output of the state quantity detection unit is equal to or less than a target value. The control unit calculates the amount of decrease in detection sensitivity due to aging of the state quantity detection unit based on the output value of the state quantity detection unit and past output values ​​of the state quantity detection unit, and adjusts the target value based on the amount of decrease. Effect of the Invention

[0011] According to the present disclosure, it is possible to advantageously adjust the state quantity of a substance in the air in the room to an amount expected by a user even if the detection sensitivity of the state quantity detection unit deteriorates with age. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram showing a configuration of a ventilation device equipped with an automatic control device according to a first embodiment. [Diagram 2] FIG. 1 is a block diagram showing a functional configuration of a remote controller according to a first embodiment; [Diagram 3] 1 is a flowchart showing a procedure of feedback control of a control unit of an automatic control device according to a first embodiment. [Figure 4] FIG. 1 is a time chart for explaining a basic feedback control operation of the automatic control device according to the first embodiment; [Diagram 5] A flowchart showing an operation procedure in which a control unit of the automatic control device according to the first embodiment changes a target value in feedback control. [Figure 6] FIG. 1 is a time chart for explaining a control operation in which a control unit of the automatic control device according to the first embodiment changes a target value in feedback control; [Figure 7] A flowchart showing an operation procedure in which a control unit of an automatic control device in accordance with a second embodiment changes a target value in feedback control. [Figure 8] FIG. 11 is a time chart for explaining a control operation in which a control unit of an automatic control device according to a second embodiment changes a target value in feedback control; [Figure 9] A block diagram showing a configuration of an air purifier according to a fifth embodiment. [Figure 10] FIG. 1 is a block diagram showing a hardware configuration of a control unit according to the first to fifth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an automatic control device according to an embodiment will be described in detail with reference to the drawings.

[0014] Embodiment 1 1 is a block diagram showing the configuration of a ventilation device equipped with an automatic control device according to the first embodiment. The ventilation device 100 according to the first embodiment is a device equipped with a ventilation function capable of adjusting the state quantity of airborne substances in indoor air. The ventilation device 100 includes an automatic control device 10 and a blower 6.

[0015] The state quantities of airborne substances in indoor air include, for example, indoor odor concentration and indoor PM2.5 concentration. The indoor odor concentration is the state quantity of odor components in indoor air. The PM2.5 concentration is the state quantity of PM2.5 in indoor air.

[0016] The controlled object of the automatic control device 10 according to the first embodiment is the ventilation device 100 having a ventilation function capable of adjusting the state quantity of airborne substances in the indoor air. That is, the automatic control device 10 automatically performs feedback control of the operation of the ventilation device 100 having a ventilation function capable of adjusting the state quantity of airborne substances in the indoor air. More specifically, the controlled object of the automatic control device 10 is the blower 6.

[0017] The ventilation machine is a state quantity adjustment machine equipped with a function of adjusting the state quantities of airborne substances in indoor air, such as indoor odor concentration and indoor PM2.5 concentration. The ventilation machine in the ventilation device 100 is the blower 6. Therefore, the automatic control device 10 automatically feedback controls the operation of the blower 6, which is a state quantity adjustment machine. The ventilation device 100 can be said to be a state quantity adjustment device equipped with a function of adjusting the state quantities of airborne substances in indoor air.

[0018] The automatic control device 10 is incorporated in the ventilation device 100, and includes an odor sensor 1, a control unit 2, a communication unit 3, a drive circuit 4, and a remote controller 5. In the following, the remote controller may be simply referred to as a remote control.

[0019] The odor sensor 1 is a state quantity detection unit that detects the indoor odor concentration, which is the state quantity of the airborne substances in the indoor air, and outputs the detection result to the control unit 2. That is, the odor sensor 1 is a state quantity detection unit that detects the state quantity of the airborne substances in the indoor air, and outputs the detection result to the control unit 2. The odor sensor 1 outputs a voltage corresponding to the detection result to the control unit 2. That is, the odor sensor 1 converts the detection result of the indoor odor concentration, which is the indoor state quantity, into a voltage and outputs it to the control unit 2. That is, the output value of the detection result of the indoor odor concentration in the odor sensor 1 to the control unit 2 is a voltage value.

[0020] A heater resistor (not shown) is mounted inside the odor sensor 1. The heater resistor serves to keep the odor sensor 1, which is a state quantity detection unit, at a temperature suitable for detecting state quantities such as odor concentration in the room, and to draw indoor air into the odor sensor 1 by generating an updraft due to heat generated by the heater resistor.

[0021] The control unit 2 includes a microcomputer, and feedback controls the operation of the blower 6 via a drive circuit 4 so that the output value of the odor sensor 1 is equal to or lower than a preset target value. The control unit 2 performs feedback control in which the output value of the odor sensor 1 is used to control the operation of the blower 6.

[0022] The communication unit 3 communicates with a remote controller communication unit 54 of the remote controller 5, which will be described later.

[0023] The drive circuit 4 controls the operation of the blower 6 under the control of the control unit 2.

[0024] The remote control 5 receives operation commands for the ventilation device 100 from the user and transmits the commands to the control unit 2. The remote control 5 is a remote control device that allows the user to perform operations related to starting and stopping the operation of the ventilation device 100. The remote control 5 receives commands for controlling the operation of the ventilation device 100 from the user. The remote control 5 transmits various commands received from the user to the control unit 2. The remote control 5 may be a remote control dedicated to the ventilation device 100, or may be a terminal device such as a smartphone installed with application software capable of remotely controlling the ventilation device 100 and capable of communicating with the communication unit 3. In the first embodiment, a case will be described in which the remote control 5 is a remote control dedicated to the ventilation device 100.

[0025] 2 is a block diagram showing a functional configuration of the remote controller according to the first embodiment. The remote controller 5 includes a remote controller operation unit 51, a remote controller display unit 52, a remote controller storage unit 53, a remote controller communication unit 54, and a remote controller control unit 55. The above components of the remote controller 5 can exchange information with each other.

[0026] The remote control operation unit 51 is an interface for remotely controlling the operation of the ventilation device 100, and accepts operations related to the operation of the ventilation device 100 from a user. When the remote control operation unit 51 accepts an operation from the user, it transmits a signal corresponding to the user's operation to the remote control control unit 55 as an operation signal.

[0027] The remote control display unit 52 displays various information related to the ventilator 100. The remote control display unit 52 receives a signal transmitted from the remote control control unit 55, and displays various information based on the signal.

[0028] The remote control storage unit 53 stores various information related to the ventilation operation of the ventilation device 100, and temporarily or long-term stores information such as the setting contents to be displayed on the remote control display unit 52 and image data related to the setting contents.

[0029] The remote control communication unit 54 communicates with the communication unit 3. The remote control communication unit 54 receives a signal transmitted from the remote control control unit 55, and transmits the signal to the communication unit 3. The remote control communication unit 54 also receives a signal transmitted from the communication unit 3, and transmits the signal to the remote control control unit 55.

[0030] The communication between the remote control communication unit 54 and the communication unit 3 may be wireless communication or wired communication. In the first embodiment, the remote control 5 and the communication unit 3 are wirelessly connected, and the communication between the remote control communication unit 54 and the communication unit 3 is wireless communication.

[0031] The remote control control unit 55 controls the overall operation of the remote control 5. The remote control control unit 55 controls the remote control 5 based on an operation signal transmitted from the remote control operation unit 51. The remote control control unit 55 controls the remote control display unit 52 to display various information.

[0032] The blower 6 operates under the control of the control unit 2 and the drive circuit 4, and blows air to ventilate the room.

[0033] Next, the basic feedback control performed by the control unit 2 of the automatic control device 10 according to the first embodiment will be described. FIG. 3 is a flowchart showing the procedure of feedback control by the control unit of the automatic control device according to the first embodiment. FIG. 4 is a time chart for explaining the basic feedback control operation of the automatic control device according to the first embodiment. The vertical axis of the upper diagram of FIG. 4 is the output value of the odor sensor 1. The horizontal axis of the upper diagram of FIG. 4 is time. The vertical axis of the lower diagram of FIG. 4 is the control state of the blower 6. The horizontal axis of the lower diagram of FIG. 4 is time.

[0034] As shown in the time chart of Fig. 4, under the control of the automatic control device 10, the blower 6 is turned on at time T0 to start operation, turned off at time T1 to stop operation, turned on at time T2 to start operation, and turned off at time T3 to stop operation. The basic feedback control operation of the automatic control device 10 according to the first embodiment will be described with reference to Figs. 3 and 4.

[0035] First, in step S110, at time T0, the automatic control device 10 starts automatic operation of the ventilation device 100. Specifically, when the control unit 2 of the automatic control device 10 receives a command to start operation of the ventilation device 100 from the remote control 5 at time T0, it performs control to start operation of the blower 6 and to start energizing the odor sensor 1. As a result, the operation of the blower 6 starts at time T0, and ventilation of the room by the ventilation device 100 starts.

[0036] When the current is applied to the heater resistor mounted inside the odor sensor 1, the internal temperature of the odor sensor 1 rises, and the odor sensor 1 starts detecting the odor concentration, which is the state quantity of the odor components in the indoor air, and outputting the detection result to the control unit 2. A certain amount of output stabilization time ST is required for the temperature inside the odor sensor 1 to stabilize and for the odor concentration to be accurately detected and the detection result to be output to the control unit 2. During the predetermined output stabilization time ST, the control unit 2 does not use the output value of the odor sensor 1 for feedback control of the blower 6, and forcibly operates the blower 6 regardless of the output value of the odor sensor 1. In state A at time T0 when the odor sensor 1 starts to be energized, the output value of the odor sensor 1 is 0.

[0037] When the internal temperature of the odor sensor 1 increases after the power supply is started, odor components adhering to the internal wall surface of the odor sensor 1 or the heater resistor are released into the odor sensor 1 by the heat generated by the heater resistor. The odor components released into the odor sensor 1 increase the concentration of the odor components in the air inside the odor sensor 1. When the odor sensor 1 reacts to the odor components released into the odor sensor 1, the output of the odor sensor 1 shows a steep increase as shown in the upper diagram of FIG. 4. This causes the output value of the odor sensor 1 to rise sharply. The odor component in this case is, for example, hydrogen. Hydrogen is odorless, but is detected by the odor sensor 1.

[0038] Next, as long as there are odor components adhering to the inner wall surface or heater resistor of the odor sensor 1, the odor components continue to be released into the odor sensor 1. At the point of state B where the output value of the odor sensor 1 rises sharply, as shown in the upper diagram of FIG. 4, the output value of the odor sensor 1 reaches a peak value. After that, as the odor components adhering to the inner wall surface or heater resistor of the odor sensor 1 are depleted, the amount of odor components released into the odor sensor 1 decreases. Furthermore, the released odor components are diffused through the ventilation hole of the odor sensor 1 from the air inside the odor sensor 1, where the concentration of the odor components is high, to the air outside the odor sensor 1, where the concentration of the odor components is low. Finally, the concentration of the odor components in the air inside the odor sensor 1 decreases to the same concentration as that in the air outside the odor sensor 1.

[0039] After the concentration of odor components in the air inside the odor sensor 1 and the concentration of odor components in the air outside the odor sensor 1 become the same concentration, the odor sensor 1 becomes able to detect and output the correct odor concentration in the room, i.e., the state quantity of the odor components in the indoor air.

[0040] During an output stabilization time ST from when the odor sensor 1 starts to be energized until the correct indoor odor concentration can be detected and output, the control unit 2 does not use the output value of the odor sensor 1 for feedback control of the blower 6. The output stabilization time ST is, for example, 3 minutes.

[0041] The output stabilization time ST can be determined during development of the ventilation device 100 by measuring the output value after the start of power supply to the odor sensor 1 and measuring the time until the temperature inside the odor sensor 1 stabilizes and the odor concentration can be accurately detected. The method of determining the output stabilization time ST is not particularly limited. For example, if the output stabilization time is determined as a part specification of the odor sensor 1 alone, the output stabilization time may be used as it is for the output stabilization time ST. Information on the output stabilization time ST is stored in a memory built into the microcomputer of the control unit 2 during manufacture of the ventilation device 100.

[0042] Next, in step S120, the control unit 2 determines whether or not the stable output time ST has elapsed from time T0. Specifically, the control unit 2 determines whether or not the stable output time ST has elapsed from time T0 by using a timer function or a clock function of the control unit 2. In Fig. 4, time T1 is the end time of the stable output time ST.

[0043] If it is determined that the output stable time ST has not elapsed since time T0, the result in step S120 is No, and the process returns to step S120. If it is determined that the output stable time ST has elapsed since time T0, the result in step S120 is Yes, and the process proceeds to step S130.

[0044] In step S130, the control unit 2 performs feedback control of the blower 6 using the output value of the odor sensor 1. That is, after the output stabilization time ST has elapsed from time T0, the control unit 2 uses the output value of the odor sensor 1 transmitted from the odor sensor 1 for the feedback control of the blower 6. That is, in FIG. 4, after state C at time T1, the control unit 2 uses the output value of the odor sensor 1 for the feedback control of the blower 6.

[0045] Specifically, when the output value of the odor sensor 1 exceeds a preset target value TV, the control unit 2 sends an operation signal to the drive circuit 4, which is a command to operate the blower 6, to operate the blower 6. In addition, when the output value of the odor sensor 1 is equal to or less than the target value TV, the control unit 2 sends a stop signal to the drive circuit 4, which is a command to stop the blower 6, to stop the blower 6. The control unit 2 uses the output value of the odor sensor 1 to implement feedback control of the blower 6.

[0046] 4, the output value of the odor sensor 1 remains below the target value TV after time T1, then rises and exceeds the target value TV at time T2. After that, the output value of the odor sensor 1 further rises and then decreases, reaching the target value TV at time T3, and then decreasing again. Therefore, the control unit 2 turns on the blower 6 at time T2 to start the operation of the blower 6, and turns off the blower 6 at time T3 to stop the operation of the blower 6.

[0047] The target value TV is a reference value of the output value of the odor sensor 1, which the control unit 2 compares with the output value of the odor sensor 1 in order to determine whether or not to operate the blower 6 based on the output value of the odor sensor 1. That is, the target value TV is a reference value of the output value of the state quantity detection unit, which the control unit 2 compares with the output value of the state quantity detection unit in order to determine whether or not to operate the blower 6 based on the output value of the state quantity detection unit. A general reference value of the odor concentration of indoor air may be used as the target value TV, or the user may be allowed to set it himself. That is, a general reference value of the state quantity of an airborne substance in indoor air may be used as the target value TV, or the user may be allowed to set it himself.

[0048] When a general reference value is used for the target value TV, information on the general reference value is stored in a memory built into a microcomputer mounted in the control unit 2 when the ventilation device 100 is manufactured.

[0049] Furthermore, in the case where the user is allowed to set the target value TV by himself / herself, for example, a volume resistor (not shown) may be mounted on the remote control 5, and the remote control 5 may transmit information on the result of the user adjusting the volume resistor to the control unit 2. The control unit 2 can obtain the target value TV corresponding to the adjusted volume resistance value transmitted from the remote control 5 by previously storing the adjustment result of the volume resistor, i.e., correspondence information showing the relationship between the adjusted volume resistance value and the target value TV. The correspondence information is stored in a memory built in a microcomputer mounted on the control unit 2 when the ventilator 100 is manufactured.

[0050] By carrying out the above-mentioned processing, the automatic control device 10 feedback controls the blower 6 of the ventilation device 100 so that the output value of the odor sensor 1 becomes equal to or less than a preset target value TV. As a result, when the blower 6 operates, the ventilation device 100 exhausts polluted air from inside the room to the outside, and also introduces fresh outside air into the room, thereby ventilating the air inside the room until it reaches a preset cleanliness level.

[0051] The inlet for introducing fresh outside air into the room may be provided separately from the ventilation device 100, or the ventilation device 100 itself may be provided with an intake and exhaust function.

[0052] Furthermore, if the inlet for fresh outside air into the room is provided at a position relatively close to the ventilation device 100, or if the ventilation device 100 itself has an intake and exhaust function, the cleanliness of the indoor air at a position relatively close to the ventilation device 100 may be high, but the cleanliness of the indoor air at a position relatively far from the ventilation device 100 may be low. For this reason, when the output value of the odor sensor 1 goes from exceeding the target value TV to being equal to or less than the target value TV, control may be performed to continue operating the blower 6 for a predetermined duration. The duration is, for example, 10 minutes.

[0053] Next, a control will be described in which the control unit 2 of the automatic control device 10 determines the degree of deterioration over time of the detection sensitivity of the odor sensor 1, and changes the target value TV based on the determined degree of deterioration over time of the detection sensitivity of the odor sensor 1. When performing the above-mentioned feedback control, the control unit 2 of the automatic control device 10 performs control to change the target value TV based on the degree of deterioration over time of the detection sensitivity of the odor sensor 1, as will be described below. Hereinafter, the deterioration over time of the detection sensitivity of the odor sensor 1 may be referred to as deterioration over time of the odor sensor 1.

[0054] FIG. 5 is a flowchart showing an operation procedure in which the control unit of the automatic control device according to the first embodiment changes a target value in feedback control. FIG. 6 is a time chart for explaining a control operation in which the control unit of the automatic control device according to the first embodiment changes a target value in feedback control. FIG. 6 is a diagram corresponding to the above-mentioned FIG. 4. The vertical axis of the upper diagram of FIG. 6 is the output value of the odor sensor 1. The horizontal axis of the upper diagram of FIG. 6 is time. The vertical axis of the lower diagram of FIG. 6 is the control state of the blower 6. The horizontal axis of the lower diagram of FIG. 6 is time. The control operation in which the control unit 2 of the automatic control device 10 according to the first embodiment changes the target value TV will be explained using FIG. 5 and FIG. 6.

[0055] First, in step S210, at time T0, the ventilation device 100 starts automatic operation and starts passing electricity through the odor sensor 1. Specifically, when the control unit 2 of the automatic control device 10 receives a command to start operation of the ventilation device 100 from the remote control 5 at time T0, it controls the blower 6 to start operation and starts passing electricity through the odor sensor 1. As a result, the operation of the blower 6 starts at time T0, and ventilation of the room by the ventilation device 100 starts.

[0056] Next, in step S220, the control unit 2 acquires the peak value of the output value of the odor sensor 1 immediately after the start of energization of the odor sensor 1. That is, after the start of energization of the odor sensor 1, the control unit 2 stores the output value of the odor sensor 1, monitors the output value of the odor sensor 1, and acquires the peak value of the output value of the odor sensor 1.

[0057] In the first embodiment, the control unit 2 uses the peak value of the output value of the odor sensor 1 when the output value of the odor sensor 1 rises sharply immediately after the start of energization of the odor sensor 1 in determining the degree of aging deterioration of the odor sensor 1. The peak value of the output value of the odor sensor 1 may be simply referred to as the peak value of the output value.

[0058] Next, in step S230, the control unit 2 calculates the amount of decrease in the peak value of the output value of the odor sensor 1 immediately after the start of energization of the odor sensor 1 from the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100. In other words, the control unit 2 calculates the amount of decrease in the current peak value from the initial peak value.

[0059] The current peak value is the peak value of the output value of the odor sensor 1 currently measured by the odor sensor 1 immediately after the odor sensor 1 starts being energized.

[0060] The initial peak value is the peak value of the output value of the odor sensor 1 measured by the odor sensor 1 at the beginning of use of the ventilation device 100 immediately after the start of power supply to the odor sensor 1. The control unit 2 stores the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100.

[0061] 6, a characteristic curve showing the relationship between the output value of odor sensor 1 and time when ventilation device 100 first begins to be used is shown by a solid line as characteristic curve 11. Also, in the upper diagram of Fig. 6, a characteristic curve showing the relationship between the output value of odor sensor 1 currently measured by odor sensor 1 and time is shown by a dashed line as characteristic curve 12. The output value of odor sensor 1 currently measured by odor sensor 1 is the output value of odor sensor 1 measured by odor sensor 1 after odor sensor 1 has deteriorated over time.

[0062] In the example of the upper diagram of FIG. 6, the initial peak value is 5V. The current peak value has decreased to 4.5V. From these values, the peak value of the output value of the odor sensor 1 after deterioration over time of the odor sensor 1 has decreased by 0.5V, that is, by 10%. That is, the control unit 2 calculates the amount of decrease of the peak value of the output value of the odor sensor 1 immediately after the start of power supply to the odor sensor 1 from the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100 as 0.5V. In this case, the control unit 2 determines that the detection sensitivity of the odor sensor 1 has decreased by 10%. That is, the control unit 2 determines that the amount of decrease in the detection sensitivity of the odor sensor 1 is 10%. The amount of decrease in the detection sensitivity of the odor sensor 1 is the degree of deterioration over time of the detection sensitivity of the odor sensor 1.

[0063] Next, in step S240, the control unit 2 calculates a post-deterioration target value TV2, which is the target value TV of the odor sensor 1 after aging deterioration, based on the amount of decrease from the initial peak value of the output value immediately after the odor sensor 1 starts being energized.

[0064] In the example of the upper diagram of Fig. 6, the control unit 2 determines that the detection sensitivity of the odor sensor 1 has decreased by 10%, and therefore decreases the target value TV after aging by 10%. That is, the control unit 2 determines the amount of decrease in the peak value of the output value of the odor sensor 1 as the amount of decrease in the detection sensitivity of the odor sensor 1, decreases the target value TV, and calculates the target value TV after aging. The control unit 2 decreases the target value TV after aging by the same rate as the decrease rate of the peak value of the output value of the odor sensor 1 after aging and the decrease rate of the detection sensitivity of the odor sensor 1 after aging, and calculates the target value TV after aging.

[0065] 6, the initial target value TV1, which is the target value TV when the ventilation device 100 is first used, is 2.5 V. Therefore, the control unit 2 changes the post-deterioration target value TV2 after deterioration over time to 2.25 V, which is a 10% decrease from the initial target value TV1, i.e., a 0.25 V decrease from the initial target value TV1. That is, the control unit 2 calculates the post-deterioration target value TV2 after deterioration over time using the peak value of the output value of the odor sensor 1 when the output value of the odor sensor 1 suddenly increases immediately after the start of power supply to the odor sensor 1, as an index of deterioration over time of the detection sensitivity of the odor sensor 1.

[0066] Even if the odor concentration in the room is the same, the detection sensitivity of the odor sensor 1 decreases by 10% after aging of the odor sensor 1, and the output value of the odor sensor 1 also decreases by 10%. Therefore, the control unit 2 resets the target value TV after aging to 10% lower, which is the same rate as the decrease rate of the detection sensitivity of the odor sensor 1 after aging from the initial state. That is, as described above, the control unit 2 sets the post-deterioration target value TV2 after aging to 2.25 V, which is 10% lower than the initial target value TV1. Then, after resetting the target value TV, the control unit 2 performs feedback control of the blower 6 based on the post-deterioration target value TV2, which is the reset target value TV, so that the blower 6 can be operated for the same time as in the initial state.

[0067] That is, regardless of whether the odor sensor 1 has deteriorated over time, the control unit 2 adjusts the target value TV using the peak value of the output value of the odor sensor 1 for the same odor concentration in the room as an index of deterioration of the detection sensitivity of the odor sensor 1 over time, and feedback-controls the blower 6 based on the adjusted target value TV. Therefore, even if the detection sensitivity of the odor sensor 1 has deteriorated over time, the automatic control device 10 can operate the blower 6 for the same time as the initial time. This allows the user to continuously enjoy comfort without feeling the deterioration of the odor sensor 1. That is, regardless of whether the odor sensor 1 has deteriorated over time, the control unit 2 feedback-controls the blower 6 to keep the odor concentration in the same room below the target value TV, so that the user can continuously enjoy comfort without feeling the deterioration of the odor sensor 1.

[0068] The reason why the peak value of the output value of the odor sensor 1 when the output value of the odor sensor 1 suddenly rises immediately after the start of power supply to the odor sensor 1 can be used as an index of deterioration of the detection sensitivity of the odor sensor 1 over time is as follows.

[0069] Immediately after the start of powering the odor sensor 1, the odor components adhering to the internal wall surfaces and heater resistor are rapidly released due to the rise in temperature, so most of the odor components in the air inside the odor sensor 1 are released components, and the proportion of the odor components originally contained in the air in the room becomes extremely small. In other words, the output value of the odor sensor 1 immediately after powering the odor sensor 1 is a constant peak value that is hardly affected by the odor concentration in the air in the room at the time the odor components are detected, and can be used as an index of deterioration over time of the detection sensitivity of the odor sensor 1.

[0070] Furthermore, in order to minimize the variation in the peak value of the output value of the odor sensor 1 from day to day, the peak values ​​of the output value for a predetermined number of days may be stored in a memory built into a microcomputer implemented in the control unit 2, and the average value of the peak values ​​of the output value of the odor sensor 1 during the period of the predetermined number of days may be used as an index of deterioration over time of the detection sensitivity of the odor sensor 1. The predetermined number of days is, for example, 30 days.

[0071] However, since deterioration of the detection sensitivity of the odor sensor 1 over time cannot be recovered, if the peak value of the output value of the odor sensor 1 immediately after the start of power supply rises after a certain day, it is assumed that the odor sensor 1 has been replaced with a new one. In this case, the peak value of the output value of the odor sensor 1 immediately after the start of power supply before the rise after a certain day is not used as an indicator of deterioration of the detection sensitivity of the odor sensor 1 over time, but only the peak value of the output value of the odor sensor 1 after the rise after a certain day is used as an indicator of deterioration of the detection sensitivity of the odor sensor 1 over time.

[0072] To explain by way of example, a condition such as "when the currently measured peak output value of the odor sensor 1 has risen beyond a predetermined rise threshold of 0.3 V, relative to the peak output value immediately before the rise, which was adopted as an index of deterioration over time, for a predetermined period of five consecutive days" is stored in a memory built into a microcomputer implemented in the control unit 2. The peak output value immediately before the rise is the peak output value when current was applied to the odor sensor 1 immediately before a certain day, in the case where the peak output value of the odor sensor 1 immediately after the start of current application rises on a certain day.

[0073] If this condition is met, the control unit 2 determines that the odor sensor 1 has been replaced with a new one, and does not use the peak value of the output value of the odor sensor 1 from six days ago or earlier as an index of deterioration over time of the detection sensitivity of the odor sensor 1. At this point, the control unit 2 uses the average value of the peak values ​​of the output values ​​for the past five days as an index of deterioration over time of the detection sensitivity of the odor sensor 1. Then, the control unit 2 uses the average value of the peak values ​​of the output values ​​for the past six days as an index of deterioration over time of the detection sensitivity of the odor sensor 1 the next day, and the average value of the peak values ​​of the output values ​​for the past seven days as an index of deterioration over time of the detection sensitivity of the odor sensor 1 the day after that, and so on, until the 30th day is reached, only the average value of the peak values ​​of the output values ​​for days less than 30 days is used.

[0074] The control unit 2 may use a predetermined number of times instead of the above-mentioned predetermined period to determine the deterioration over time of the detection sensitivity of the odor sensor 1. That is, for example, a condition such as "when the currently measured peak value of the output value of the odor sensor 1 has risen by more than a predetermined increase threshold of 0.3 V compared to the peak value of the output value immediately before the increase, which has been adopted as an index of deterioration over time, and the measurement has been performed five times in succession, which is a predetermined number of times" may be stored in a memory built in a microcomputer implemented in the control unit 2.

[0075] If this condition is satisfied, the control unit 2 determines that the odor sensor 1 has been replaced with a new one, and does not use the peak value of the output value of the odor sensor 1 prior to the above-mentioned five consecutive times as an indicator of deterioration over time of the detection sensitivity of the odor sensor 1. At this point, the control unit 2 uses the average value of the peak values ​​of the above-mentioned five consecutive times as an indicator of deterioration over time of the detection sensitivity of the odor sensor 1. Then, the control unit 2 uses the average value of the peak values ​​of the consecutive five times as an indicator of deterioration over time of the detection sensitivity of the odor sensor 1 the next time after the five consecutive times, and uses the average value of the peak values ​​of the output values ​​of six times (the five consecutive times and the next to the five consecutive times) as an indicator of deterioration over time of the detection sensitivity of the odor sensor 1, and so on, until the 30th time is reached, the control unit 2 uses the average value of only the peak values ​​of the output values ​​fewer than 30 times.

[0076] 6 shows an example in which the peak value of the output value of the odor sensor 1 immediately after the start of energization of the odor sensor 1 drops by 10% for the sake of illustration, but under actual usage conditions of the ventilation device 100, a 10% drop in the detection sensitivity of the odor sensor 1 is equivalent to several years of aging deterioration of the detection sensitivity of the odor sensor 1. Therefore, in practice, a daily drop in the peak value of the output value of the odor sensor 1 of about 0.1% or 0.01% is measured and used to determine the changed target value TV.

[0077] In the first embodiment, the odor sensor 1 that detects the indoor odor concentration is shown as the state quantity detection unit that detects the state quantity of an airborne substance in the indoor air, but the state quantity detection unit is not limited to the odor sensor 1. The state quantity detection unit may be another sensor such as a PM2.5 sensor that detects the indoor PM2.5 concentration, which is the state quantity of an airborne substance in the indoor air.

[0078] According to the above-mentioned automatic control device 10, an automatic control device is realized that controls a state quantity adjustment machine that adjusts the state quantity of aerial substances in the air in a room, and that includes a state quantity detection unit that detects and outputs the state quantity of the aerial substance in the room, and a control unit that feedback controls the state quantity adjustment machine based on the output of the state quantity detection unit so that the output of the state quantity detection unit is below a target value, and the control unit calculates the amount of decrease in detection sensitivity of the state quantity detection unit due to deterioration over time based on the output value of the state quantity detection unit and past output values ​​of the state quantity detection unit, and adjusts the target value based on the amount of decrease.

[0079] As described above, the ventilation device 100 according to the first embodiment includes the automatic control device 10. The control unit 2 of the automatic control device 10 uses the peak value of the output value of the odor sensor 1 when the output value of the odor sensor 1 rises sharply immediately after the start of energization of the odor sensor 1 as an index of deterioration of the detection sensitivity of the odor sensor 1 over time.

[0080] The control unit 2 acquires the peak value of the output value of the odor sensor 1 immediately after the start of energization of the odor sensor 1. The control unit 2 also calculates the amount of decline in the peak value of the output value of the odor sensor 1 immediately after the start of energization of the odor sensor 1 from the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100. The control unit 2 also calculates a target value TV2, which is the target value TV of the odor sensor 1 after deterioration over time, based on the amount of decline in the peak value of the output value immediately after the start of energization of the odor sensor 1 from the initial state, and resets the target value TV to the target value TV2. After resetting the target value TV, the control unit 2 performs feedback control of the blower 6 based on the post-deterioration target value TV2, which is the reset target value TV.

[0081] In this way, the control unit 2 of the automatic control device 10 calculates the amount of decrease in the detection sensitivity of the odor sensor 1 due to deterioration over time from the peak output value of the odor sensor 1 immediately after the start of power supply to the odor sensor 1, and adjusts the target value based on the calculation result. In other words, the automatic control device 10 performs feedback control of the blower 6 by lowering the target value by an amount corresponding to the amount of decrease in the detection sensitivity of the odor sensor 1 due to deterioration over time.

[0082] As a result, even if the detection sensitivity of the odor sensor 1 has decreased due to aging, the automatic control device 10 can feedback control the ventilation device 100 until the indoor air reaches a preset cleanliness level, and adjust the odor concentration in the room after cleaning to a level that the user does not find uncomfortable. In other words, the automatic control device 10 controls the ventilation operation of the ventilation device 100 so that the odor concentration in the room continues to be equal to or lower than the target value, regardless of the decrease in detection sensitivity due to aging of the odor sensor 1, and can adjust the odor concentration in the room to the level expected by the user, thereby improving indoor comfort.

[0083] Therefore, according to the automatic control device 10 of embodiment 1, even if the detection sensitivity of the odor sensor 1, which is the state quantity detection unit, deteriorates over time, the state quantity of the airborne substance in the room can be adjusted to the amount expected by the user.

[0084] Embodiment 2 In the second embodiment, other functions of the automatic control device 10 described above will be described. In the second embodiment, items that are not specifically described are the same as those in the first embodiment, and the same functions and configurations are described using the same reference numerals. Also, the description of the same functions and configurations as those in the first embodiment will be omitted.

[0085] In the second embodiment, when the output value of the odor sensor 1 suddenly rises immediately after the start of power supply to the odor sensor 1, the peak value of the output value of the odor sensor 1 reaches the upper limit that can be output, and the difference from the first embodiment is that the duration of the upper limit value output is used as an indicator of the deterioration over time of the detection sensitivity of the odor sensor 1, instead of the peak value immediately after the start of power supply to the odor sensor 1.

[0086] The duration of the upper limit output is the time during which the upper limit of the output value of the odor sensor 1 continues to be output when the output value of the odor sensor 1 rises sharply immediately after the odor sensor 1 starts being energized.

[0087] FIG. 7 is a flowchart showing an operation procedure in which the control unit of the automatic control device in the second embodiment changes a target value in feedback control. FIG. 8 is a time chart for explaining a control operation in which the control unit of the automatic control device according to the second embodiment changes a target value in feedback control. FIG. 8 is a diagram corresponding to FIG. 6 described above. The vertical axis of the upper diagram of FIG. 8 is the output value of the odor sensor 1. The horizontal axis of the upper diagram of FIG. 8 is time. The vertical axis of the lower diagram of FIG. 8 is the control state of the blower 6. The horizontal axis of the lower diagram of FIG. 8 is time. The control operation in which the control unit 2 of the automatic control device 10 in the second embodiment changes a target value in feedback control will be explained using FIG. 7 and FIG. 8.

[0088] First, in step S310, at time T0, automatic operation of the ventilation device 100 is started and electricity is started to flow to the odor sensor 1. Specifically, when the control unit 2 of the automatic control device 10 receives a command to start operation of the ventilation device 100 from the remote control 5 at time T0, it controls the blower 6 to start operation and controls the start of electricity to the odor sensor 1. As a result, the operation of the blower 6 is started at time T0, and ventilation of the room by the ventilation device 100 is started.

[0089] Next, in step S320, the control unit 2 acquires the duration of the upper limit value output of the odor sensor 1 immediately after the start of energization of the odor sensor 1. That is, the control unit 2 stores the output value of the odor sensor 1 after the start of energization of the odor sensor 1, monitors the output value of the odor sensor 1, and acquires the duration of the upper limit value output for the output value of the odor sensor 1.

[0090] In the second embodiment, the control unit 2 uses the duration of the upper limit output for the output value of the odor sensor 1 when the output value of the odor sensor 1 rises sharply immediately after the start of power supply to the odor sensor 1 in determining the degree of aging deterioration of the odor sensor 1. Note that the duration of the upper limit output for the output value of the odor sensor 1 may be simply referred to as the duration of the upper limit output.

[0091] Next, in step S330, the control unit 2 calculates the amount of decrease in the duration of the upper limit output immediately after the start of power supply to the odor sensor 1 from the duration of the upper limit output when the ventilation device 100 was first used. That is, the control unit 2 calculates the amount of decrease in the current duration of the upper limit output from the initial duration of the upper limit output. The amount of decrease in the current duration of the upper limit output from the initial duration of the upper limit output represents the degree of deterioration over time of the detection sensitivity of the odor sensor 1.

[0092] The duration of the current upper limit value output is the time during which the upper limit value of the output value of the odor sensor 1 continues to be output when the output value of the odor sensor 1 suddenly increases immediately after the odor sensor 1 starts to be powered, as measured by the odor sensor 1 during the current operation of the ventilation device 100.

[0093] The duration of the initial upper limit output is the time during which the upper limit of the output value of the odor sensor 1 is continuously output when the output value of the odor sensor 1 rises sharply immediately after the start of power supply to the odor sensor 1, as measured by the odor sensor 1 in the initial period after the ventilation device 100 is first used. The control unit 2 stores the duration of the initial upper limit output in the initial period after the ventilation device 100 is first used.

[0094] 8, a characteristic curve showing the relationship between the output value of odor sensor 1 and time when ventilation device 100 first begins to be used is shown by a solid line as characteristic curve 13. Also, in the upper diagram of Fig. 8, a characteristic curve showing the relationship between the output value of odor sensor 1 currently measured by odor sensor 1 and time is shown by a dashed line as characteristic curve 14. The output value of odor sensor 1 currently measured by odor sensor 1 is the output value of odor sensor 1 measured by odor sensor 1 after odor sensor 1 has deteriorated over time.

[0095] When the odor sensor 1 detects an odor concentration equal to or greater than a specified amount, the output value reaches an upper limit. A direct current (DC) 5V power supply is supplied to the odor sensor 1 of the automatic control device 10. Therefore, the upper limit output value of the odor sensor 1 is DC 5V. And, since the odor sensor 1 detects an odor concentration equal to or greater than a specified amount immediately after the odor sensor 1 starts to be energized, the output value reaches the upper limit DC 5V, as shown in the time chart of FIG. 8.

[0096] When the ventilation device 100 is first used, the initial duration of the upper limit output is 60 seconds. The current duration of the upper limit output has decreased to 20 seconds. From these values, the duration of the upper limit output of the odor sensor 1 after aging deterioration of the odor sensor 1 has decreased by 40 seconds. In other words, the control unit 2 calculates that the amount of decrease in the duration of the upper limit output of the odor sensor 1 immediately after the start of power supply to the odor sensor 1 from the duration of the upper limit output at the beginning of use of the ventilation device 100 is 40 seconds.

[0097] Next, in step S340, the control unit 2 calculates a post-deterioration target value TV4, which is a target value of the odor sensor 1 after aging, based on the amount of decrease in the duration of the upper limit output immediately after the odor sensor 1 starts being energized, from the initial period.

[0098] In the example of the upper diagram of Fig. 8, the control unit 2 reduces the target value by 8%, from 2.5 V to 2.3 V. The control unit 2 determines by what percentage to reduce the target value, based on correlation information indicating the relationship between the amount of reduction in the duration of the upper limit value output immediately after the start of power supply to the odor sensor 1 and the amount of reduction in the detection sensitivity of the odor sensor 1 due to aging deterioration.

[0099] During development of the ventilation device 100, a correlation between the amount of decrease in the duration of the upper limit output immediately after the start of power supply to the odor sensor 1 and the amount of decrease in the detection sensitivity of the odor sensor 1 due to aging is verified. Then, based on the verification results, correlation information indicating the relationship between the amount of decrease in the duration of the upper limit output immediately after the start of power supply to the odor sensor 1 and the amount of decrease in the detection sensitivity of the odor sensor 1 due to aging is created in advance. The correlation information is stored in a memory built into the microcomputer of the control unit 2 during manufacturing of the ventilation device 100.

[0100] Then, the control unit 2 determines by what percentage to reduce the target value based on the amount of reduction in the duration of the current upper limit value output from the duration of the initial upper limit value output calculated in step S330 and the correlation information stored in the memory.

[0101] To explain by way of example, in the example in the upper diagram of Fig. 8, correlation information is stored in the built-in memory of the microcomputer of the control unit 2, which indicates the correlation that "if the duration of the upper limit output is reduced by 10 seconds, the detection sensitivity of the odor sensor 1 is reduced by 2%." In the example in the upper diagram of Fig. 8, the duration of the upper limit output immediately after the start of power supply to the odor sensor 1, i.e., the time during which the output value of the odor sensor 1 reaches the DC 5V upper limit immediately after the start of power supply to the odor sensor 1, is reduced by 40 seconds from the initial time. Therefore, the control unit 2 determines that the detection sensitivity of the odor sensor 1 has decreased by 8%, and reduces the target value TV after aging by 8%.

[0102] 8, the initial target value TV3, which is the target value TV when the ventilation device 100 is first used, is 2.5 V. Therefore, the control unit 2 changes the post-deterioration target value TV4 after deterioration over time to 2.3 V, which is an 8% decrease from the initial target value TV3, that is, a 0.2 V decrease from the initial target value TV3. In other words, the control unit 2 calculates the post-deterioration target value TV4 after deterioration over time using the duration of the upper limit output of the odor sensor 1 when the output value of the odor sensor 1 suddenly increases immediately after the start of power supply to the odor sensor 1 as an index of deterioration over time of the detection sensitivity of the odor sensor 1.

[0103] Even if the odor concentration in the room is the same, the detection sensitivity of the odor sensor 1 decreases by 8% after aging of the odor sensor 1, and the output value of the odor sensor 1 also decreases by 8%. Therefore, the control unit 2 resets the target value after aging to 8% lower, which is the same rate of decrease from the initial detection sensitivity of the odor sensor 1 after aging. That is, as described above, the control unit 2 sets the post-deterioration target value TV4 after aging to 2.3 V, which is 8% lower than the initial target value TV3. Then, after resetting the target value, the control unit 2 performs feedback control of the blower 6 based on the post-deterioration target value TV4, which is the reset target value, thereby making it possible to operate the blower 6 for the same time as in the initial period.

[0104] That is, regardless of whether or not the odor sensor 1 has deteriorated over time, the control unit 2 uses the duration of the upper limit output of the odor sensor 1 for the same indoor odor concentration as an index of deterioration of the detection sensitivity of the odor sensor 1 to feedback-control the blower 6, so that the user can continuously enjoy comfort without feeling the deterioration of the odor sensor 1. That is, regardless of whether or not the odor sensor 1 has deteriorated over time, the control unit 2 feedback-controls the blower 6 to keep the odor concentration in the same room at or below the target value, so that the user can continuously enjoy comfort without feeling the deterioration of the odor sensor 1.

[0105] The reason why the duration of the upper limit output of the odor sensor 1 when the output value of the odor sensor 1 suddenly rises immediately after the odor sensor 1 is turned on can be used as an index of deterioration of the detection sensitivity of the odor sensor 1 over time is as follows.

[0106] When the output value of the odor sensor 1 reaches an upper limit by detecting an odor concentration above a specified amount, even if the output value has decreased due to deterioration of the detection sensitivity of the odor sensor 1 over time, there is no difference in the peak value, so the deterioration of the detection sensitivity of the odor sensor 1 over time cannot be determined from the peak value of the output value of the odor sensor 1.

[0107] However, after a certain period of time has passed since the start of energizing the odor sensor 1, the concentration of the odor components inside the odor sensor 1 gradually decreases due to the depletion of the odor components emitted from the inner wall surface and heater resistor of the odor sensor 1 and the diffusion of the odor components into the air outside the odor sensor 1. At this time, if the detection sensitivity of the odor sensor 1 has deteriorated over time, it will stop outputting the upper limit output value sooner than the initial odor sensor 1. In other words, the time during which the odor sensor 1 continues to output the upper limit output value differs depending on whether the detection sensitivity of the odor sensor 1 has deteriorated over time. For this reason, the duration of the upper limit output, which is the time during which the odor sensor 1 continues to output the upper limit output value when the output value of the odor sensor 1 rises sharply immediately after the start of energizing the odor sensor 1, can be used as an index of the deterioration of the detection sensitivity of the odor sensor 1 over time.

[0108] 8 shows an example in which the duration of the upper limit output is reduced by 40 seconds immediately after the start of energization of the odor sensor 1 for ease of illustration, but under actual usage conditions of the ventilation device 100, a 40-second reduction in the duration of the upper limit output is an amount of decrease equivalent to several years of aging deterioration of the detection sensitivity of the odor sensor 1. Therefore, in practice, the daily reduction in the duration of the upper limit output of the odor sensor 1, which is about 0.1 seconds or 0.01 seconds, is measured and used to determine the target value after the change.

[0109] Furthermore, the upper limit output value of the odor sensor 1 may have a certain degree of margin. For example, even if the actual upper limit output value is DC 5V, by regarding DC 4.8V or higher as the upper limit, it is possible to eliminate the influence of minute fluctuations in the voltage value, which is the output value from the odor sensor 1, caused by variations in the performance of parts or electrical noise, etc.

[0110] Furthermore, the control unit 2 may use the duration of the upper limit output of the odor sensor 1 when the odor sensor 1 outputs an upper limit output value, as an index of deterioration over time of the detection sensitivity of the odor sensor 1, and may use the peak value of the output value of the odor sensor 1 when the odor sensor 1 does not output an upper limit output value. In this case, the control unit 2 automatically determines which of the duration of the upper limit output of the odor sensor 1 or the peak value of the output value of the odor sensor 1 to use as an index of deterioration over time of the detection sensitivity of the odor sensor 1.

[0111] Furthermore, the control unit 2 may calculate the post-deterioration target value using both the duration of the upper limit output of the odor sensor 1 and the peak value of the output value of the odor sensor 1 as an index of deterioration over time of the detection sensitivity of the odor sensor 1. For example, the control unit 2 may set the final post-deterioration target value to the average value of the post-deterioration target value calculated using the duration of the upper limit output of the odor sensor 1 as an index of deterioration over time of the detection sensitivity of the odor sensor 1 and the post-deterioration target value calculated using the peak value of the output value of the odor sensor 1 as an index of deterioration over time of the detection sensitivity of the odor sensor 1. By calculating the post-deterioration target value using both the duration of the upper limit output of the odor sensor 1 and the peak value of the output value of the odor sensor 1 as an index of deterioration over time of the detection sensitivity of the odor sensor 1, the degree of deterioration over time of the detection sensitivity of the odor sensor 1 can be determined in a wider range.

[0112] As described above, in the second embodiment, the control unit 2 uses the duration of the upper limit output of the odor sensor 1 immediately after the start of energization of the odor sensor 1 as an index of deterioration of the detection sensitivity of the odor sensor 1 over time.

[0113] The control unit 2 acquires the duration of the upper limit output of the odor sensor 1 immediately after the start of energization of the odor sensor 1. The control unit 2 also calculates the amount of decrease in the duration of the upper limit output from the duration of the upper limit output at the beginning when the ventilation device 100 was first used. The control unit 2 also calculates a post-deterioration target value TV4, which is the target value TV after aging deterioration of the odor sensor 1, based on the amount of decrease in the duration of the upper limit output from the beginning, and resets the target value TV to the post-deterioration target value TV4. After resetting the target value TV, the control unit 2 performs feedback control of the blower 6 based on the post-deterioration target value TV4, which is the reset target value.

[0114] Thus, in the second embodiment, as in the first embodiment, even if the detection sensitivity of the odor sensor 1 has decreased due to aging, the automatic control device 10 can feedback control the ventilation device 100 until the indoor air reaches a preset cleanliness level, and adjust the odor concentration in the room after cleaning to a level that does not cause discomfort to the user. That is, in the second embodiment as well, the automatic control device 10 controls the ventilation operation of the ventilation device 100 so that the odor concentration in the room continues to be equal to or lower than the target value, regardless of the decrease in detection sensitivity due to aging of the odor sensor 1, and can adjust the odor concentration in the room to the level expected by the user, thereby improving the comfort of the room.

[0115] Embodiment 3 In the third embodiment, other functions of the automatic control device 10 described above will be described. In the third embodiment, a function that enables the automatic control device 10 to more accurately measure and determine the degree of aging deterioration of the odor sensor 1 will be described. In the third embodiment, items that are not specifically described will be the same as those in the first or second embodiment, and the same functions and configurations will be described using the same reference numerals. Also, a description of the same functions and configurations as those in the first or second embodiment will be omitted.

[0116] In embodiment 3, the power supply to the odor sensor 1 is stopped for a predetermined power stop time, and then power is supplied to the odor sensor 1 again to determine the degree of deterioration of the odor sensor 1 over time, which is different from embodiment 1 and embodiment 2.

[0117] The power supply stop time is the time during which power supply to the odor sensor 1 is stopped after the ventilation operation of the ventilation device 100 is stopped, until the aging deterioration determination process, which is a process for determining the degree of aging deterioration of the odor sensor 1, is performed.

[0118] The power supply stop time is the time during which power supply to the odor sensor 1 is stopped when the ventilation operation of the ventilation device 100 is stopped, and is the time during which power supply to the odor sensor 1 is stopped after the ventilation operation of the ventilation device 100 is stopped until an aging deterioration determination process is performed, which is a process for determining the degree of aging deterioration of the odor sensor 1. The power supply stop time is determined in advance and stored in a memory built into the microcomputer of the control unit 2. The power supply stop time is, for example, 5 hours.

[0119] The state of the odor components adhering to the inner wall surface and heater resistor of the odor sensor 1 changes as time passes while the power supply to the odor sensor 1 is stopped. For this reason, the degree of deterioration of the odor sensor 1 over time can be measured more accurately by stopping the power supply to the odor sensor 1 for the same power supply stop time each time and then starting the power supply to the odor sensor 1 again.

[0120] Furthermore, in order to accurately measure the degree of deterioration of the odor sensor 1 over time, it is preferable that the power supply cut-off time be set to nighttime when there is little human activity in the room and the indoor air is less polluted.

[0121] For example, when the ventilation operation of the ventilation device 100 is stopped at 9 p.m., the control unit 2 performs control to stop the supply of electricity to the odor sensor 1. Then, the control unit 2 performs the aging deterioration determination process at 2 a.m., five hours after 9 p.m. In other words, the control unit 2 performs control to supply electricity to the odor sensor 1 for a predetermined determination current supply time of three minutes at 2 a.m., five hours after 9 p.m. Then, the control unit 2 determines the degree of aging deterioration of the odor sensor 1 as shown in the above-described first or second embodiment, and stores the determination result of the degree of aging deterioration of the odor sensor 1 in a memory built in a microcomputer included in the control unit 2.

[0122] Thereafter, for example, when the ventilation operation of the ventilation device 100 is started at 8:00, the control unit 2 does not perform control to determine the degree of deterioration of the odor sensor 1 as described in the above-mentioned embodiment 1 or embodiment 2. The control unit 2 sets the determination result of the degree of deterioration of the odor sensor 1 determined in the aging deterioration determination process performed at 2:00 as the determination result of the degree of deterioration of the odor sensor 1 at the start of this ventilation operation of the ventilation device 100.

[0123] Thereafter, for example, when the ventilation operation of the ventilation device 100 is stopped at 10 p.m., the control unit 2 performs control to stop the supply of electricity to the odor sensor 1. Then, the control unit 2 performs the aging deterioration determination process at 3 a.m., five hours after 10 p.m. In other words, the control unit 2 performs control to supply electricity to the odor sensor 1 for a predetermined determination current supply time of three minutes, at 3 a.m., five hours after 10 p.m. Then, the control unit 2 determines the degree of aging deterioration of the odor sensor 1, as shown in the above-described first or second embodiment, and stores the determination result of the degree of aging deterioration of the odor sensor 1 in a memory built in the microcomputer of the control unit 2.

[0124] Thereafter, for example, when the ventilation operation of the ventilation device 100 is started at 8:00, the control unit 2 does not perform control to determine the degree of deterioration of the odor sensor 1 as described in the above-mentioned embodiment 1 or embodiment 2. The control unit 2 sets the determination result of the degree of deterioration of the odor sensor 1 determined in the aging deterioration determination process performed at 3:00 as the determination result of the degree of deterioration of the odor sensor 1 at the start of this ventilation operation of the ventilation device 100.

[0125] As described above, in the third embodiment, when the ventilation operation of the ventilation device 100 is stopped, the control unit 2 stops the supply of electricity to the odor sensor 1 for the same power supply stop time every time from when the ventilation operation of the ventilation device 100 is stopped. After that, the control unit 2 supplies electricity to the odor sensor 1 for a predetermined determination power supply time to determine the degree of deterioration of the odor sensor 1, and stores information on the determined degree of deterioration. This allows the automatic control device 10 to accurately measure and determine the degree of deterioration of the odor sensor 1.

[0126] Furthermore, by stopping the supply of electricity to the odor sensor 1 during the night, the degree of deterioration of the odor sensor 1 over time can be measured more accurately.

[0127] Embodiment 4 In the fourth embodiment, other functions of the automatic control device 10 described above will be described. In the fourth embodiment, a function of the automatic control device 10 notifying the user of information on the lifespan of the odor sensor 1 will be described. In the fourth embodiment, items that are not specifically described will be the same as those in the first to third embodiments, and the same functions and configurations will be described using the same reference numerals. Also, descriptions of the same functions and configurations as those in the first to third embodiments will be omitted.

[0128] In embodiment 4, the automatic control device 10 uses past judgment results of the degree of deterioration of the odor sensor 1 to calculate the rate at which the deterioration of the odor sensor 1 will progress, predicts when the odor sensor 1 will reach the end of its life, and notifies the user of the predicted time when the odor sensor 1 will reach the end of its life as advance notice information about the life of the odor sensor 1.

[0129] Before the odor sensor 1 reaches the end of its life, the control unit 2 transmits life display instruction information, which is information instructing the display of life prediction information, to the remote control unit 55 of the remote control 5. The life display instruction information includes the life prediction information. Upon receiving the life display instruction information, the remote control unit 55 transmits the life prediction information to the remote control display unit 52 of the remote control 5, and causes the remote control display unit 52 to display the life prediction information.

[0130] The following describes an example of a method for predicting the end of life of the odor sensor 1. For example, the end of life of the odor sensor 1 is defined as the time when the current peak value, which is the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100, drops by 30% from the initial peak value.

[0131] The control unit 2 determines and predicts the time when the odor sensor 1 will reach the end of its life based on an initial output value peak value, which is the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100, and a timing determination condition, which is a determination condition for when the odor sensor 1 will reach the end of its life.

[0132] The initial output peak value is the peak value of the output value of the odor sensor 1 at the beginning of use of the ventilation device 100, and is stored in a memory built into the microcomputer of the control unit 2 when the ventilation device 100 is manufactured. In addition, the initial output peak value may be measured, for example, when the user uses the ventilation device 100 for the first time, and stored in a memory built into the microcomputer of the control unit 2.

[0133] The timing determination condition is a condition for determining when the life of the odor sensor 1 will be reached, and is a condition that the peak value of the output value of the odor sensor 1 is reduced by 30% from the initial peak value. In other words, the timing determination condition is that the current peak value is reduced by 30% from the initial peak value. The timing determination condition is stored in a memory built into the microcomputer of the control unit 2 when the ventilation device 100 is manufactured.

[0134] The control unit 2 stores in a memory built into the microcomputer the degree of daily deterioration of the odor sensor 1 and the accumulated power-on time, which is the accumulated time that power has been applied to the odor sensor 1 since the ventilation device 100 was started to be used. Here, it is assumed that the time that power was applied to the odor sensor 1 until the current peak value of the odor sensor 1 decreased by 20% from the initial peak value was 2000 hours. The control unit 2 calculates the rate of deterioration of the odor sensor 1 as follows: the current peak value decreases by 10% from the initial peak value for every 1000 hours that power is applied to the odor sensor 1. The control unit 2 then predicts that the odor sensor 1 will reach the end of its life by applying power to the odor sensor 1 for another 1000 hours.

[0135] The control unit 2 transmits life display instruction information including life prediction information to the remote control 5, indicating that the odor sensor 1 will reach the end of its life if electricity is passed through the odor sensor 1 for 1000 hours from the current state. The remote control 5 displays the life prediction information by displaying characters or illustrations on the remote control display unit 52, which is a liquid crystal screen, to notify the user of the end of the life of the odor sensor 1.

[0136] The remote control display unit 52 is not limited to a liquid crystal screen, and may be a light emitting diode (LED) lamp, etc. In other words, the method of notifying the user of the life expectancy forecast information is not limited to a specific method, such as notifying the user of the life expectancy forecast information by turning on an LED lamp.

[0137] As described above, in the fourth embodiment, the control unit 2 can calculate the rate of deterioration of the odor sensor 1 by accumulating the determination results of the degree of deterioration of the odor sensor 1, and can therefore predict when the odor sensor 1 will reach the end of its life. By looking at the life prediction information displayed on the remote control display unit 52, the user can purchase a new odor sensor 1 in advance and replace the odor sensor 1 currently in use with a new odor sensor 1 before the odor sensor 1 currently in use reaches the end of its life.

[0138] As a result, the ventilation device 100 does not become unable to perform feedback control of the blower 6 due to the odor sensor 1 becoming unusable due to the end of its life, and can control the ventilation operation so that the odor concentration in the room continues to be below the target value, thereby improving indoor comfort.

[0139] Embodiment 5. In the first to fourth embodiments, the automatic control device 10 is implemented in the ventilation device 100, but the automatic control device 10 may be implemented in an air purifier. In other words, the object to be controlled by the automatic control device 10 may be an electric dust collector.

[0140] 9 is a block diagram showing the configuration of an air purifier according to the fifth embodiment. The air purifier 200 according to the fifth embodiment is a device having a normal air cleaning function capable of adjusting the amount of airborne substances in the indoor air. The air purifier 200 includes an automatic control device 20 and an electric dust collector 21.

[0141] The controlled object of the automatic control device 20 according to the fifth embodiment is an air purifier 200 having an air cleaning function capable of adjusting the state quantity of airborne substances in the indoor air. That is, the automatic control device 20 automatically performs feedback control of the operation of the air purifier 200 having an air cleaning function capable of adjusting the state quantity of airborne substances in the indoor air. More specifically, the controlled object of the automatic control device 20 is an electric dust collector 21.

[0142] The ventilation machine in the air purifier 200 is the electric dust collector 21. Therefore, the automatic control device 20 automatically feedback controls the operation of the electric dust collector 21, which is a state quantity adjustment machine. The air purifier 200 can be said to be a state quantity adjustment device equipped with a function for adjusting the state quantities of airborne substances in the indoor air.

[0143] The automatic control device 20 is incorporated in an air purifier 200. The automatic control device 20 has the same functions as the automatic control device 10 according to the first embodiment, except that the object to be controlled is an electric dust collector 21.

[0144] The automatic control device 10 of the air purifier 200 according to the above-mentioned fifth embodiment feedback controls the air purifier 200 until the indoor air reaches a preset cleanliness level, even if the detection sensitivity of the odor sensor 1 decreases due to aging, and can adjust the odor concentration in the room after cleaning to a level that the user does not find uncomfortable. In other words, the automatic control device 10 of the air purifier 200 controls the air cleaning operation of the air purifier 200 so that the odor concentration in the room continues to be equal to or lower than the target value, regardless of the decrease in detection sensitivity due to aging of the odor sensor 1, and can adjust the odor concentration in the room to the level expected by the user, thereby improving indoor comfort.

[0145] Therefore, according to the air purifier 200 of the fifth embodiment, even if the detection sensitivity of the odor sensor 1, which is the state quantity detection unit, deteriorates over time, the state quantity of the airborne substance in the room can be adjusted to the amount expected by the user.

[0146] Next, the hardware configuration of the control unit according to the first to fifth embodiments will be described. The control unit 2 is realized by a processing circuit. The processing circuit may be a control circuit having a processor, or may be dedicated hardware. FIG. 10 is a block diagram showing the hardware configuration of the control unit 2 according to the first to fifth embodiments. As shown in FIG. 10, the control circuit for realizing the control unit 2 includes a processor 111 and a memory 112. The processor 111 and the memory 112 can transmit and receive data to and from each other via a bus, for example. The processor 111 executes the function of the control unit 2 by reading and executing a program stored in the memory 112. The processor 111 includes, for example, one or more of a CPU (Central Processing Unit) and a DSP (Digital Signal Processor).

[0147] The memory 112 includes one or more of a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), and an EEPROM (Electrically Erasable Programmable Read Only Memory). The programs stored in the memory 112 are provided by, for example, a recording medium. The recording medium includes one or more of a non-volatile or volatile semiconductor memory, a magnetic disk, a flexible memory, an optical disk, a compact disk, and a DVD (Digital Versatile Disc). The programs stored in the memory 112 may be provided by a communication medium. When the processing circuit is a dedicated hardware, the processing circuit includes, for example, at least one or more of a FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), and a system LSI (Large Scale Integration). The memory 112 is also used as a temporary memory in each process executed by the processor 111.

[0148] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0149] Various aspects of the present disclosure are summarized below as appendices.

[0150] (Appendix 1) An automatic control device for controlling a state quantity adjusting machine that adjusts the state quantity of an airborne substance in indoor air, a state quantity detection unit that detects and outputs a state quantity of the airborne substance in the room; a control unit that feedback controls the state quantity adjustment machine based on an output of the state quantity detection unit so that the output of the state quantity detection unit is equal to or smaller than a target value; Equipped with the control unit calculates an amount of decrease in detection sensitivity due to aging deterioration of the state quantity detection unit based on an output value of the state quantity detection unit and past output values ​​of the state quantity detection unit, and adjusts the target value based on the amount of decrease; An automatic control device comprising: (Appendix 2) the control unit calculates an amount of decrease in detection sensitivity due to aging deterioration of the state quantity detection unit based on a peak value of the output of the state quantity detection unit after a predetermined output stabilization time has elapsed since starting to energize the state quantity detection unit and a past peak value of the output value of the state quantity detection unit after a predetermined output stabilization time has elapsed since starting to energize the state quantity detection unit; 2. The automatic control device according to claim 1, (Appendix 3) the control unit calculates an amount of decrease in detection sensitivity due to aging of the state quantity detection unit based on a duration of an upper limit value output, which is a time during which an upper limit value of an output value of the state quantity detection unit is continuously output immediately after a current is started to be applied to the state quantity detection unit, and a duration of the upper limit value output in the past; 2. The automatic control device according to claim 1, (Appendix 4) the control unit starts energizing the state quantity detection unit after stopping energization to the state quantity detection unit for a predetermined energization stop time, and calculates a decrease in detection sensitivity due to aging deterioration of the state quantity detection unit based on an output value of the state quantity detection unit and a past output value of the state quantity detection unit; 2. The automatic control device according to claim 1, (Appendix 5) a remote controller that receives an operation command related to the operation of the state quantity adjustment machine and transmits the operation command to the control unit; the control unit predicts, based on the amount of decrease, a time when the amount of decrease will reach a predetermined progress level, and transmits a prediction result to the remote controller to display it on the remote controller; 5. The automatic control device according to claim 1, (Appendix 6) the control unit adjusts the target value based on the current output value of the state quantity detection unit when the currently measured output value of the state quantity detection unit exceeds a predetermined increase width threshold value for a predetermined period or a predetermined number of times in succession, compared with the output value of the state quantity detection unit measured immediately before; 2. The automatic control device according to claim 1, (Appendix 7) The state quantity adjusting machine is a blower; 7. The automatic control device according to any one of claims 1 to 6, (Appendix 8) The state quantity adjusting machine is an electric dust collector; 7. The automatic control device according to any one of claims 1 to 6, [Explanation of symbols]

[0151] 1 odor sensor, 2 control unit, 3 communication unit, 4 drive circuit, 5 remote controller, 6 blower, 10 automatic control unit, 11, 12, 13, 14 characteristic curve, 20 automatic control unit, 21 electrostatic precipitator, 51 remote controller operation unit, 52 remote controller display unit, 53 remote controller memory unit, 54 remote controller communication unit, 55 remote controller control unit, 100 ventilation device, 111 processor, 112 memory, 200 air purifier, ST output stabilization time, TV target value, TV1, TV3 initial target value, TV2, TV4 target value after deterioration.

Claims

1. An automatic control device for controlling a state quantity adjusting machine that adjusts the state quantity of an airborne substance in indoor air, a state quantity detection unit that detects and outputs a state quantity of the airborne substance in the room; a control unit that feedback controls the state quantity adjustment machine based on an output of the state quantity detection unit so that the output of the state quantity detection unit is equal to or smaller than a target value; Equipped with the control unit calculates an amount of decrease in detection sensitivity due to aging deterioration of the state quantity detection unit based on an output value of the state quantity detection unit and past output values ​​of the state quantity detection unit, and adjusts the target value based on the amount of decrease; An automatic control device comprising:

2. the control unit calculates an amount of decrease in detection sensitivity due to aging deterioration of the state quantity detection unit based on a peak value of the output of the state quantity detection unit after a predetermined output stabilization time has elapsed since starting to energize the state quantity detection unit and a past peak value of the output value of the state quantity detection unit after a predetermined output stabilization time has elapsed since starting to energize the state quantity detection unit; The automatic control device according to claim 1 .

3. the control unit calculates an amount of decrease in detection sensitivity due to aging of the state quantity detection unit based on a duration of an upper limit value output, which is a time during which an upper limit value of an output value of the state quantity detection unit is continuously output immediately after a current is started to be applied to the state quantity detection unit, and a duration of the upper limit value output in the past; The automatic control device according to claim 1 .

4. the control unit starts energizing the state quantity detection unit after stopping energization to the state quantity detection unit for a predetermined energization stop time, and calculates a decrease in detection sensitivity due to aging deterioration of the state quantity detection unit based on an output value of the state quantity detection unit and a past output value of the state quantity detection unit; The automatic control device according to claim 1 .

5. a remote controller that receives an operation command related to the operation of the state quantity adjustment machine and transmits the operation command to the control unit; the control unit predicts, based on the amount of decrease, a time when the amount of decrease will reach a predetermined progress level, and transmits a prediction result to the remote controller to display it on the remote controller; The automatic control device according to claim 1 .

6. the control unit adjusts the target value based on the current output value of the state quantity detection unit when the currently measured output value of the state quantity detection unit exceeds a predetermined increase width threshold value for a predetermined period or a predetermined number of times in succession, compared with the output value of the state quantity detection unit measured immediately before; The automatic control device according to claim 1 .

7. The state quantity adjusting machine is a blower; 7. An automatic control device according to claim 1, wherein

8. The state quantity adjusting machine is an electric dust collector; 7. An automatic control device according to claim 1, wherein

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