Seat heater and moving body seat

Abstract

To suppress occurrence of overshoot and hunting in temperature control when an environmental temperature is relatively high.SOLUTION: Until a temperature T detected by a thermister provided in a seat body reaches a set control switching temperature CT1, on / off control is performed to set an energization ratio for a heater, provided in the seat body, to a predetermined value or larger; and after the detected temperature T reaches the control switching temperature CT1, PID control is performed to control energization of the heater so that the detected temperature T coincides with a target temperature CT2. A calculation unit calculates a slope a of a change in the detected temperature T during a period in which the control unit performs the on / off control. A setting unit sets the control switching temperature CT1 when the inclination a of the change in the detected temperature T calculated by the calculation unit is larger than a threshold value, to be lower than the control switching temperature CT1 when the inclination a of the change in the detected temperature T is equal to or smaller than the threshold value.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to a seat heater and a seat for a moving body.

Background Art

[0002] The seat heater described in Patent Document 1 includes a heater in which a heating wire is laid on a base material provided between a seat cushion material and a seat skin, a temperature detection unit provided near the heating wire of the base material, and a temperature control unit that controls the temperature of the heater so as to approach a target temperature according to the temperature detected by the temperature detection unit. The temperature control unit calculates an estimated ambient temperature based on the temperature rise rate detected by the temperature detection unit during a period after a predetermined time from the start of heating of the heater, and corrects the target temperature so that the lower the estimated ambient temperature, the lower the target temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, a seat heater is configured to exhibit a desired temperature rise performance when the ambient temperature is relatively low, such as below freezing. For example, when the ambient temperature is -20°C, as shown in FIG. 13 for example, temperature control results without overshoot or hunting can be obtained. On the other hand, when the ambient temperature is relatively high, there is a problem that overshoot or hunting as shown in FIG. 14 occurs in temperature control because the temperature rises faster than expected and the control cannot catch up. Note that FIG. 14 shows temperature control results when the ambient temperature is 15°C as an example.

[0005] The present disclosure has been made in consideration of the above facts, and an object thereof is to obtain a seat heater and a seat for a moving body that can suppress overshoot and hunting from occurring in temperature control when the ambient temperature is relatively high.

Means for Solving the Problems

[0006] The seat heater according to the first aspect performs first control to set the energization ratio of the heater provided on the seat to a predetermined value or more until the detected temperature by the temperature detection unit provided on the seat reaches a set control switching temperature, and after the detected temperature reaches the control switching temperature, a control unit that performs second control to control the energization of the heater so that the detected temperature matches the target temperature, a calculation unit that calculates the slope a of the change in the detected temperature during the period in which the control unit performs the first control, and a setting unit that sets the control switching temperature when the slope a calculated by the calculation unit is greater than a threshold value to be lower than the control switching temperature when the slope a is less than or equal to the threshold value.

[0007] In the first aspect, the slope a of the change in the detected temperature during the period in which the control unit performs the first control changes according to the ambient temperature, and as the ambient temperature increases, the slope a also increases. In the first aspect, since the control switching temperature when the slope a is greater than the threshold value is set lower than the control switching temperature when the slope a is less than or equal to the threshold value, the second control is started earlier, so that overshoot and hunting can be suppressed from occurring in temperature control when the ambient temperature is relatively high.

[0008] According to a second aspect, in the first aspect, the control unit performs PID control as the second control.

[0009] According to the second aspect, compared with the case of performing other control such as PI control as the second control, overshoot and hunting can be more effectively suppressed from occurring in the temperature control of the seat.

[0010] In the third aspect, in the first aspect or the second aspect, the calculation unit calculates the slope a based on the detected temperature T1 at the time when a first predetermined time t1 has elapsed since the start of the first control and the detected temperature T2 at the time when a second predetermined time t2 that is greater than the first predetermined time t1 has elapsed since the start of the first control.

[0011] Immediately after the control unit starts the first control, the heat released from the heater is consumed for raising the temperature of the members existing around the heater, so the correlation between the slope a and the ambient temperature becomes small. In contrast, in the third aspect, as the detected temperature used for calculating the slope a, instead of the temperature at the start time of the first control, the detected temperature T1 at the time when a first predetermined time t1 has elapsed since the start of the first control is used. Thereby, a value that more accurately reflects the ambient temperature can be obtained as the slope a, and the control switching temperature can be set so as to more effectively suppress the occurrence of overshoot and hunting in the temperature control of the seat.

[0012] In the fourth aspect, in any one of the first aspect to the third aspect, the setting unit temporarily sets the control switching temperature, and when the slope a is smaller than a first threshold value A1, sets the control switching temperature higher than the temporarily set value, and when the slope a is greater than or equal to a second threshold value A2 that is greater than the first threshold value A1, sets the control switching temperature lower than the temporarily set value.

[0013] In the fourth aspect, when the slope a is within the range of the first threshold value A1 to the second threshold value A2, it becomes a dead zone where the control switching temperature is not changed from the temporarily set value, so it is possible to suppress the change in the control switching temperature from becoming too sensitive to the change in the slope a.

[0014] In the fifth aspect, in any one of the first aspect to the fourth aspect, the setting unit changes the threshold value for the slope a according to whether or not the detected temperature T at the time when a predetermined time t has elapsed since the start of the first control is equal to or higher than a predetermined temperature threshold value.

[0015] According to the fifth aspect, even when the relationship between the environmental temperature and the slope changes depending on the environmental temperature, an appropriate temperature can be set as the control switching temperature.

[0016] The moving body seat according to the sixth aspect is provided with the seat heater according to any one of the first aspect to the fifth aspect.

[0017] In the sixth aspect, since the seat heater according to any one of the first aspect to the fifth aspect is provided, it is possible to suppress the occurrence of overshoot and hunting in temperature control when the environmental temperature is relatively high, similar to the first aspect.

Effect of the Invention

[0018] The present disclosure has an effect of suppressing the occurrence of overshoot and hunting in temperature control when the environmental temperature is relatively high.

Brief Description of the Drawings

[0019]

Figure 1

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Figure 14

Embodiments for Carrying Out the Invention

[0020] Hereinafter, an example of an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0021] 〔First Embodiment〕 The vehicle seat 10 shown in FIG. 1 includes a seat body 12. The seat body 12 is provided in the passenger compartment of a vehicle, which is an example of a moving body, and is seated by a passenger of the vehicle. Note that the vehicle seat 10 is an example of a seat for a moving body according to the present disclosure, and the seat body 12 is an example of a seat in the present disclosure.

[0022] The seat body 12 includes a seat cushion portion 14, a seat back portion 16, and a headrest portion 18. The headrest portion 18 is attached to the upper end of the seat back portion 16 in the vehicle vertical direction so as to be slidable along the length direction of the seat back portion 16. The lower end of the seat back portion 16 in the vehicle vertical direction is attached to the rear end of the seat cushion portion 14 in the vehicle front-rear direction via a rotation mechanism (not shown), and is rotatable about an axis along the vehicle width direction with respect to the seat cushion portion 14.

[0023] In addition, a heater 20 is provided on the seat body 12. The heater 20 includes a first heater mat 22 laid near the skin of the seat cushion portion 14 and a second heater mat 24 laid near the skin of the seat back portion 16. Further, a thermistor 26 is provided near the rear end portion in the vehicle front-rear direction of the seat cushion portion 14. The thermistor 26 is disposed near the heating wire of the heater 20 and detects the temperature of the heating wire of the heater 20. The thermistor 26 is an example of the temperature detection portion in the present disclosure.

[0024] In addition, the vehicle seat 10 includes a seat heater ECU (Electronic Control Unit) 32, and the seat heater ECU 32 is housed in the seat cushion portion 14. As shown in FIG. 2, the seat heater ECU 32 includes a CPU (Central Processing Unit) 34 and a memory 36 such as a ROM (Read Only Memory) and a RAM (Random Access Memory). Further, the seat heater ECU 32 includes a non-volatile storage portion 38 such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive), and an I / F (InterFace) portion 40. The CPU 34, the memory 36, the storage portion 38, and the I / F portion 40 are communicably connected to each other via an internal bus 42.

[0025] The heater 20 is connected to the I / F portion 40 via the heater drive portion 28, and the thermistor 26 and the seat heater switch 30 are respectively connected thereto. The heater drive portion 28 energizes the heater 20 in accordance with an instruction from the seat heater ECU 32 (a control portion 44 described later). The seat heater switch 30 is turned on and off by an occupant sitting on the seat body 12.

[0026] In addition, the storage unit 38 of the seat heater ECU 32 stores a seat heater control program 41. The seat heater ECU 32 functions as a control unit 44, a calculation unit 46, and a setting unit 48 shown in FIG. 3 when the seat heater control program 41 is read from the storage unit 38 and expanded in the memory 36, and the seat heater control program 41 expanded in the memory 36 is executed by the CPU 34.

[0027] When the seat heater switch 30 is turned on, the control unit 44 performs a heater control process (described later). In this heater control process, until the detected temperature T by the thermistor 26 reaches the set control switching temperature CT1, the control unit 44 performs on-off control to set the energization ratio of the heater 20 to a predetermined value or more (for example, 90 to 100%). Further, after the detected temperature T by the thermistor 26 reaches the control switching temperature CT1, the control unit 44 performs PID control to control the energization of the heater 20 so that the detected temperature T matches the target temperature CT2. Note that the above on-off control is an example of the first control in the present disclosure, and the above PID control is an example of the second control in the present disclosure.

[0028] The calculation unit 46 calculates the slope a of the change in the detected temperature T during the period when the control unit 44 performs on-off control. Further, when the slope a of the change in the detected temperature T calculated by the calculation unit 46 is greater than a threshold value, the setting unit 48 sets the control switching temperature CT1 lower than the control switching temperature CT1 when the slope a of the change in the detected temperature T is less than or equal to the threshold value.

[0029] Next, as the operation of the first embodiment, first, with reference to FIG. 4, the heater control process executed by the control unit 44 triggered by the seat heater switch 30 being turned on will be described.

[0030] In step 60 of the heater control process, the control unit 44 acquires the control switching temperature CT1 set by the setting unit 48 from the setting unit 48. Also, in step 62, the control unit 44 acquires the temperature T detected by the thermistor 26 from the thermistor 26. Then, in step 64, the control unit 44 determines whether the temperature T acquired in step 62 is equal to or higher than the control switching temperature CT1 acquired in step 60.

[0031] If the determination in step 64 is affirmative, the process proceeds to step 66. In step 66, the control unit 44 executes on-off control to energize the heater 20 at an energization ratio equal to or higher than a predetermined value via the heater drive unit 28. In the next step 70, the control unit 44 determines whether the seat heater switch 30 has been turned off. If the determination in step 70 is negative, the process returns to step 60. Therefore, until the detected temperature T by the thermistor 26 reaches the set control switching temperature CT1, on-off control is performed on the heater 20.

[0032] Also, when the detected temperature T by the thermistor 26 reaches the set control switching temperature CT1, the determination in step 64 is negative and the process proceeds to step 68. In step 68, the control unit 44 executes PID control to control the energization of the heater 20 via the heater drive unit 28 so that the detected temperature T matches the target temperature CT2. This PID control continues while the seat heater switch 30 is in the on state. Then, when the seat heater switch 30 is turned off, the determination in step 70 is affirmative and the heater control process ends.

[0033] Subsequently, referring to FIG. 5, when the control unit 44 starts executing the heater control process and the heater 20 is turned on (energization of the heater 20 is started), the control switching temperature setting process performed by the calculation unit 46 and the setting unit 48 will be described.

[0034] In step 80 of the control switching temperature setting process, the setting unit 48 temporarily sets the control switching temperature CT1. Note that the control switching temperature CT1 temporarily set here may be, for example, a value fixedly determined in advance, or the detected temperature T by the thermistor 26 may be acquired prior to the temporary setting of the control switching temperature CT1, and the value may be changed according to the acquired detected temperature T. Also, at an arbitrary timing after the temporary setting of the control switching temperature CT1 (for example, the timing when the first predetermined time t1 has elapsed after the heater 20 is turned on as described below), the detected temperature T by the thermistor 26 is acquired, and the temporarily set value of the control switching temperature CT1 may be reset according to the acquired thermistor temperature T.

[0035] In step 82, the calculation unit 46 determines whether or not the first predetermined time t1 has elapsed since the heater 20 was turned on. If the determination in step 82 is negative, step 82 is repeated until the determination becomes positive. When the first predetermined time t1 has elapsed since the heater 20 was turned on, the determination in step 82 becomes positive and the process proceeds to step 84. In step 84, the calculation unit 46 acquires the detected temperature T1 from the thermistor 26 and stores the acquired detected temperature T1 in the memory 36 or the like.

[0036] Also, in step 86, the calculation unit 46 determines whether or not the second predetermined time t2 has elapsed since the heater 20 was turned on. Note that the second predetermined time t2 > the first predetermined time t1. If the determination in step 86 is negative, step 86 is repeated until the determination becomes positive. When the second predetermined time t2 has elapsed since the heater 20 was turned on, the determination in step 86 becomes positive and the process proceeds to step 88. In step 88, the calculation unit 46 acquires the detected temperature T2 from the thermistor 26 and stores the acquired detected temperature T2 in the memory 36 or the like.

[0037] In step 90, the calculation unit 46 substitutes the detected temperatures T1 and T2 stored in the memory 36 or the like into the following formula (1) to calculate the slope a (see also FIG. 6) of the change in the detected temperature T by the thermistor 26 during the period when the control unit 44 performs on / off control. a = (T2 - T1) / (t2 - t1) …(1)

[0038] In step 92, the setting unit 48 determines whether the slope a calculated by the calculation unit 46 is less than the slope threshold A. If the slope a is greater than or equal to the slope threshold A, the determination in step 92 is negative and the process proceeds to step 94. In step 94, the setting unit 48 decreases the control switching temperature CT1 temporarily set in the previous step 80. If the slope a is less than the slope threshold A, the determination in step 92 is affirmative and the process proceeds to step 96. In step 96, the setting unit 48 increases the control switching temperature CT1 temporarily set in the previous step 80.

[0039] Note that, as the change width of the control switching temperature CT1 in steps 94 and 96, a value fixed in advance may be used, or the value may be changed according to the detected temperature T acquired from the thermistor 26 at an arbitrary timing (for example, the detected temperature T1 acquired at the timing when the first predetermined time t1 has elapsed after the heater 20 is turned on).

[0040] By the above control switching temperature setting process, when the slope a of the change in the detected temperature T by the thermistor 26 is large, that is, when it is estimated that the environmental temperature is high, as shown in FIG. 7, by decreasing the control switching temperature CT1, the PID control for the heater 20 is started earlier. Thereby, as shown in FIG. 8 as an example, it is possible to suppress the occurrence of overshoot and hunting in temperature control when the environmental temperature is relatively high (FIG. 8 shows a case of 15°C as an example).

[0041] Also, when the slope a of the change in the detected temperature T by the thermistor 26 is small, that is, when it is estimated that the environmental temperature is low, as shown in FIG. 7, by increasing the control switching temperature CT1, the period during which the on-off control is performed on the heater 20 is made longer. Thereby, the time until the detected temperature T by the thermistor 26 reaches the target temperature CT2 can be shortened.

[0042] Thus, in the first embodiment, until the detected temperature T by the thermistor 26 provided on the seat body 12 reaches the control switching temperature CT1 set, the control unit 44 performs a first control to set the energization ratio of the heater 20 provided on the seat body 12 to a predetermined value or more. Further, after the detected temperature T reaches the control switching temperature CT1, the control unit 44 performs a second control to control the energization of the heater 20 so that the detected temperature T matches the target temperature CT2. The calculation unit 46 calculates the slope a of the change in the detected temperature T during the period when the control unit 44 is performing the first control. And the setting unit 48 sets the control switching temperature CT1 when the slope a of the change in the detected temperature T calculated by the calculation unit 46 is greater than the threshold value to be lower than the control switching temperature CT1 when the slope a of the change in the detected temperature T is less than or equal to the threshold value. Thereby, when the environmental temperature is relatively high, the second control is started earlier, and it is possible to suppress the occurrence of overshoot and hunting in temperature control.

[0043] Also, in the first embodiment, the control unit 44 performs PID control as the second control. Thereby, compared with the case of performing other controls such as PI control as the second control, it is possible to more effectively suppress the occurrence of overshoot and hunting in temperature control.

[0044] Also, in the first embodiment, the calculation unit 46 calculates the slope a of the change in the detected temperature T based on the detected temperature T1 at the time when the first predetermined time t1 has elapsed since the start of the first control and the detected temperature T2 at the time when the second predetermined time t2, which is greater than the first predetermined time t1 since the start of the first control, has elapsed. Thereby, a value that more accurately reflects the environmental temperature can be obtained as the slope a of the change in the detected temperature T, and the control switching temperature CT1 can be set so as to more effectively suppress the occurrence of overshoot and hunting in temperature control.

[0045] 〔Second Embodiment〕 Next, a second embodiment of the present disclosure will be described. Since this second embodiment has the same configuration as the first embodiment, the same reference numerals are assigned to each part, and the description of the configuration will be omitted. Then, referring to FIG. 9, the control switching temperature setting process according to this second embodiment will be described only for the parts different from the control switching temperature setting process (FIG. 5) described in the first embodiment.

[0046] In the control switching temperature setting process according to the second embodiment, in step 90, after the calculation unit 46 calculates the slope a of the change in the detected temperature T, it proceeds to step 100. In step 100, the setting unit 48 determines whether the slope a of the change in the detected temperature T calculated by the calculation unit 46 in step 90 is smaller than a preset slope threshold value A1.

[0047] If the determination in step 100 is affirmative, it proceeds to step 102. In step 102, the setting unit 48 increases the control switching temperature CT1 temporarily set in the previous step 80 and proceeds to step 104. If the determination in step 100 is negative, step 102 is skipped and it proceeds to step 104.

[0048] In step 104, the setting unit 48 determines whether the slope a of the change in the detected temperature T calculated by the calculation unit 46 in step 90 is greater than a preset slope threshold value A2. Note that the slope threshold value A2 > the slope threshold value A1. If the determination in step 104 is affirmative, it proceeds to step 106. In step 106, the setting unit 48 decreases the control switching temperature CT1 temporarily set in the previous step 80 and ends the control switching temperature setting process. If the determination in step 104 is negative, step 106 is skipped and the control switching temperature setting process is ended.

[0049] Note that, as the change width of the control switching temperature CT1 in Steps 102 and 106, a fixed value determined in advance may be used, or the value may be changed according to the detected temperature T obtained from the thermistor 26 at an arbitrary timing (for example, the detected temperature T1 obtained at the timing when the first predetermined time t1 has elapsed since the heater 20 was turned on).

[0050] In the case where the inclination threshold A1 < inclination a < inclination threshold A2 (the case shown in FIG. 10(A)) by the above-described control switching temperature setting process, the determinations in Steps 100 and 104 are each negated, so that the control switching temperature CT1 is not changed. Further, in the case where the inclination a > inclination threshold A2 (the case shown in FIG. 10(B)), while the determination in Step 100 is negated, the determination in Step 104 is affirmed, so that the control switching temperature CT1 is decreased by the setting unit 48. Further, in the case where the inclination a < inclination threshold A1 (the case shown in FIG. 10(C)), while the determination in Step 100 is affirmed, the determination in Step 104 is negated, so that the control switching temperature CT1 is increased by the setting unit 48.

[0051] As described above, in the second embodiment, the setting unit 48 temporarily sets the control switching temperature CT1, and when the inclination a of the change in the detected temperature T is smaller than the inclination threshold A1 (this inclination threshold A1 is an example of the first threshold A1), the control switching temperature CT1 is set higher than the temporarily set value. Further, the setting unit 48 sets the control switching temperature CT1 lower than the temporarily set value when the inclination a of the change in the detected temperature T is larger than the second threshold A2 (this inclination threshold A2 is such that the inclination threshold A2 > inclination threshold A1 and is an example of the second threshold A2). Thereby, when the inclination a is within the range of the inclination threshold A1 to the inclination threshold A2, it becomes a dead zone where the control switching temperature CT1 is not changed from the temporarily set value, so that it is possible to suppress the change in the control switching temperature CT1 with respect to the change in the inclination a from becoming too sensitive.

[0052] 〔Third Embodiment〕 Next, a third embodiment of the present disclosure will be described. Since the third embodiment has the same configuration as the first embodiment, the same reference numerals are given to each part and the description of the configuration is omitted. Then, with reference to FIG. 11, the control switching temperature setting process according to the third embodiment will be described only for the parts different from the control switching temperature setting process (FIG. 9) described in the second embodiment.

[0053] In the control switching temperature setting process according to the third embodiment, in step 90, after the calculation unit 46 calculates the slope a of the change in the detected temperature T, the process proceeds to step 98. In step 98, the setting unit 48 determines whether the detected temperature T1 stored in the memory 36 or the like is less than a preset temperature threshold n. As the temperature threshold n, for example, 0°C can be applied, but other temperatures may also be applied. Also, the detected temperature T compared with the temperature threshold n in step 98 is not limited to the detected temperature T1 obtained at the timing when the first predetermined time t1 has elapsed after the heater 20 is turned on, and the detected temperature T obtained from the thermistor 26 at an arbitrary timing may be used.

[0054] If the detected temperature T1 is less than the temperature threshold n, the determination in step 98 is affirmed and the process proceeds to step 100. In steps 100 to 106, the processes described in the second embodiment are performed. On the other hand, if the detected temperature T1 is greater than or equal to the temperature threshold n, the process proceeds from step 98 to step 108.

[0055] In step 108, the setting unit 48 determines whether the slope a of the change in the detected temperature T calculated by the calculation unit 46 in step 90 is smaller than a preset slope threshold value A1'. In this embodiment, the slope threshold value A1' ≠ the slope threshold value A1. If the determination in step 108 is affirmative, the process proceeds to step 110. In step 110, the setting unit 48 increases the control switching temperature CT1 temporarily set in the previous step 80 and proceeds to step 112. Note that the change width of the control switching temperature CT1 in step 110 may be the same as or different from the change width of the control switching temperature CT1 in step 102. If the determination in step 108 is negative, step 110 is skipped and the process proceeds to step 112.

[0056] In step 112, the setting unit 48 determines whether the slope a of the change in the detected temperature T calculated by the calculation unit 46 in step 90 is greater than a preset slope threshold value A2'. In this embodiment, the slope threshold value A2' ≠ the slope threshold value A2. If the determination in step 112 is affirmative, the process proceeds to step 114. In step 114, the setting unit 48 decreases the control switching temperature CT1 temporarily set in the previous step 80 and ends the control switching temperature setting process. Note that the change width of the control switching temperature CT1 in step 114 may be the same as or different from the change width of the control switching temperature CT1 in step 106. If the determination in step 112 is negative, step 114 is skipped and the control switching temperature setting process is ended.

[0057] In the above-described control switching temperature setting process, when the detected temperature T1 ≥ 0°C and the slope threshold A1' < slope a < slope threshold A2' (the case shown in Fig. 12(A)), the determinations in steps 108 and 112 are each negated, so the control switching temperature CT1 is not changed. Also, when the detected temperature T1 ≥ 0°C and the slope a > slope threshold A2' (the case shown in Fig. 12(B)), while the determination in step 108 is negated, the determination in step 112 is affirmed, so the control switching temperature CT1 is decreased by the setting unit 48. Further, when the detected temperature T1 ≥ 0°C and the slope a < slope threshold A1' (the case shown in Fig. 12(C)), while the determination in step 108 is affirmed, the determination in step 112 is negated, so the control switching temperature CT1 is increased by the setting unit 48.

[0058] Thus, in the third embodiment, the setting unit 48 switches the threshold for the slope a of the change in the detected temperature T to the slope thresholds A1, A2 or the slope thresholds A1', A2' according to whether the detected temperature T1 at the time when the first predetermined time t1 has elapsed since the start of the on-off control is greater than or equal to the temperature threshold n. Thereby, even when the relationship between the environmental temperature and the slope a of the change in the detected temperature T changes depending on the environmental temperature, an appropriate temperature can be set as the control switching temperature CT1.

[0059] In the third embodiment, one temperature threshold n (for example, 0°C) is set for the detected temperature T1, and the mode of switching the threshold for the slope a of the change in the detected temperature T to the slope thresholds A1, A2 or the slope thresholds A1', A2' according to whether the detected temperature T1 is greater than or equal to the temperature threshold n has been described. However, the present disclosure is not limited to this, and for the detected temperature T1, a plurality of temperature thresholds such as "-10°C < T1 < 0°C" may be set, and the slope threshold may be switched according to the magnitude relationship between the detected temperature T1 and the plurality of temperature thresholds.

[0060] Also, in the above embodiment, the mode of applying the present disclosure to the seat of a vehicle has been described. However, the moving body according to the present disclosure is not limited to a vehicle, and the present disclosure may be applied to the seats of moving bodies such as trains, airplanes, and ships.

[0061] In addition, in the above description, the seat heater control program 41 is stored (installed) in advance in the storage unit 38. However, the seat heater control program 41 can also be provided in a form recorded on a non-temporary recording medium such as an HDD, SSD, or DVD.

Explanation of Signs

[0062] 10 Vehicle seat 12 Seat body 20 Heater 26 Thermistor 32 Seat heater ECU 44 Control unit 46 Calculation unit 48 Setting unit

Claims

1. a control unit that performs a first control for setting a power supply rate of a heater provided in the seat to a predetermined value or more until a temperature detected by a temperature detection unit provided in the seat reaches a set control switching temperature, and performs a second control for controlling power supply to the heater so that the detected temperature coincides with a target temperature after the detected temperature reaches the control switching temperature; a calculation unit that calculates a gradient a of a change in the detected temperature during a period in which the control unit is performing the first control; a setting unit that sets the control switching temperature when the slope a calculated by the calculation unit is greater than a threshold value to a temperature lower than the control switching temperature when the slope a is equal to or smaller than the threshold value.

2. The seat heater according to claim 1 , wherein the control unit performs PID control as the second control.

3. 3. The seat heater according to claim 1, wherein the calculation unit calculates the slope a based on the detected temperature T1 at a point when a first predetermined time t1 has elapsed since the start of the first control, and the detected temperature T2 at a point when a second predetermined time t2 greater than the first predetermined time t1 has elapsed since the start of the first control.

4. The seat heater according to any one of claims 1 to 3, wherein the setting unit provisionally sets the control switching temperature, and when the slope a is smaller than a first threshold A1, sets the control switching temperature higher than the provisionally set value, and when the slope a is equal to or greater than a second threshold A2 that is larger than the first threshold A1, sets the control switching temperature lower than the provisionally set value.

5. The seat heater according to any one of claims 1 to 4, wherein the setting unit changes a threshold value for the slope a depending on whether the detected temperature T at a point in time t after the start of the first control is equal to or higher than a predetermined temperature threshold value.

6. A seat for a vehicle, comprising the seat heater according to any one of claims 1 to 5.

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