Seating detection device and seating monitoring system

Abstract

To provide a seating detection device that can be used by being attached to an existing chair.SOLUTION: A seating detection device includes a detection unit, a fixing unit, a power source, a switch, and a determination unit. The detection unit forms an electric field and detects a change in capacitance. The fixing unit fixes the detection unit to a chair. The power source supplies power for forming an electric field to the detection unit. The switch turns on / off the power supply from the power source to the detection unit. After the switch is turned on, on the basis of the detection of change in the capacitance via the detection unit, the determination unit sets an appropriate threshold from the change amount, and determines whether or not a person is seated on the basis of the threshold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a seating detection device and a seating monitoring system that detects when a person sits on a chair. [Background technology]

[0002] Conventionally, a seat sensor attached to the underside of a vehicle seat cushion is used as a device for detecting when a person is sitting in a chair. By attaching the seat sensor to the underside of the seat cushion in this way, the cushioning properties of the seat cushion are not impaired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-32870 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional seat occupancy sensor described above, two contacts come into contact when the seat cushion deforms when a person sits down, and the sensor outputs a signal. Therefore, with this type of seat occupancy sensor, the gap between the two contacts must be optimized to match the material and ease of deformation of the seat cushion on which the sensor is attached. In other words, this type of seat occupancy sensor must be optimized for detection sensitivity to match the characteristics of the chair to which it is attached, and it is not versatile enough to be attached to existing chairs.

[0005] The problem to be solved by the present invention is to provide a seating detection device and a seating monitoring system that can be attached to an existing chair and used. [Means for solving the problem]

[0006] The seating detection device of the embodiment includes a detection unit, a fixing unit, a power source, a switch, and a determination unit. The detection unit forms an electric field and detects changes in capacitance. The fixing unit fixes the detection unit to a chair. The power source supplies power to the detection unit to form the electric field. The switch turns on / off the power supply from the power source to the detection unit. After turning on the switch, the determination unit detects a change in capacitance via the detection unit, sets an appropriate threshold from the amount of change, and determines whether or not a person is seated based on this threshold. The judgment unit sets a provisional threshold value greater than the capacitance detected through the detection unit when no one is sitting in the chair, calculates the average value of the capacitances that exceed the provisional threshold value detected through the detection unit, and sets an appropriate threshold value from this average value.

[0007] The seating monitoring system of the embodiment includes the seating detection device described above and a monitoring device that receives and displays the determination result from the determination unit. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of how a seating detection device according to an embodiment is attached to a chair. [Figure 2] FIG. 2 is an exploded perspective view of the seating detection device of FIG. [Figure 3] FIG. 3 is a block diagram of a seating monitoring system in which the sensor board of the seating detection device of FIG. 2 is wirelessly connected to a monitoring device. [Figure 4] FIG. 4 is a flowchart for explaining an example of use of the seating detection device of FIG. [Figure 5] FIG. 5 is a diagram showing an example of a change over time in capacitance detected by the sensor device of the seating detection apparatus of FIG. [Figure 6] FIG. 6 is a perspective view showing an external appearance of a modified example of the seating detection device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment will be described with reference to the drawings. 1, the seating detection device 10 of this embodiment can be used by being attached to, for example, the back of a seat 101 of a chair 100. The seating detection device 10 can also be used by being attached to a backrest 102 or armrest 103 of the chair 100.

[0010] To improve the comfort of using the chair 100, it is desirable to install the seating detection device 10 in a location that is not directly touched by a person sitting on the chair 100 (hereinafter collectively referred to as the user). In any case, the seating detection device 10 should be installed in a location where a user sitting on the chair 100 enters the electric field formed by the seating detection device 10.

[0011] Furthermore, it is desirable to attach the seating detection device 10 in a direction in which the electrodes of a sensor substrate 14 (FIG. 2) of the seating detection device 10, which will be described later, are arranged in a direction perpendicular to the direction in which the user approaches the chair 100. For example, since the user moves from above to below the seat 101 of the chair 100 to sit down, the seating detection device 10 is attached to the underside of the seat 101 with the sensor substrate 14 in a substantially horizontal position along the seat 101.

[0012] The seating detection device 10 of this embodiment has a capacitance threshold value S as a reference for determining whether or not a person is seated, as will be described later. b Because it is self-configurable, it can be attached to and used with any type of existing chair.

[0013] 2, the seating detection device 10 has a case 12, a sensor substrate 14, and an adhesive sheet 16. The adhesive sheet 16 functions as a fixing portion as recited in the claims.

[0014] The case 12 integrally includes a rectangular frame-shaped peripheral portion 121 and a rectangular plate-shaped bottom portion 122 that closes one axial end of the peripheral portion 121. The case 12 has a rectangular opening 123 at the other axial end of the peripheral portion 121. The case 12 houses a rectangular plate-shaped sensor substrate 14 in a recess surrounded by the peripheral portion 121 and the bottom portion 122. In this embodiment, the recess is slightly larger than the sensor substrate 14, but it may be the same size as the sensor substrate 14. The seating detection device 10 has four insulating spacers 18 between the inner surface of the bottom portion 122 and the sensor substrate 14.

[0015] The case 12 is made of a conductor to block external capacitance changes to the electrodes of the sensor substrate 14. However, the case 12 does not necessarily have to be made of a conductor, and is not an essential component of the present invention. The electrodes of the sensor substrate 14 may be a printed pattern of a conductor on the surface of the substrate. The sensor substrate 14 may be a flexible printed circuit board (FPC), and the electrodes may be printed on the FPC. The spacer 18 forms a gap between the case 12 and the sensor substrate 14 to electrically isolate them. The sensor substrate 14 is placed in the recess of the case 12 with the electrodes facing outward (towards the opening 123).

[0016] The adhesive sheet 16 is placed in a position that covers the opening 123 of the case 12 while contacting the electrodes of the sensor substrate 14 placed in the recess of the case 12. The adhesive sheet 16 is made of a dielectric material such as acrylic rubber. The adhesive sheet 16 may be, for example, an elastically deformable resin sheet that has stretchability and adhesiveness, or may be double-sided tape whose material itself has adhesive properties. Note that instead of the adhesive sheet 16, the sensor substrate 14 may be fixed to the chair 100 using screws or adhesive.

[0017] 3, the sensor substrate 14 has a sensor device 20, a switch 23, a power supply 24, and a wireless device 25. The sensor device 20 functions as a detection unit as defined in the claims, and also functions as a determination unit as defined in the claims.

[0018] The sensor device 20 has a processor 21 and a memory 22. The processor 21 executes arithmetic processing. The processor 21 performs various processes based on, for example, programs stored in the memory 22 and data used in the programs. The memory 22 stores the programs, data used in the programs, and the like.

[0019] The sensor device 20 uses power supplied from the power source 24 to form an electric field via electrodes (not shown) of the sensor substrate 14, and detects a change in capacitance when a user of the chair 100 approaches. The capacitance detection method may be a self-capacitance method or a mutual capacitance method. The sensor device 20 detects a change in capacitance by detecting a threshold value S stored in the memory 22. b When a capacitance exceeding this value is detected, it is determined that the user has sat on the chair 100.

[0020] The switch 23 can be operated from outside the case 12, and the case 12 has a hole (not shown) for allowing an operating part (not shown) of the switch 23 to protrude outside the case 12. The switch 23 connects and disconnects (ON / OFF) an electrical transmission path that supplies power from the power source 24 to the sensor device 20.

[0021] The wireless device 25 communicates wirelessly with the monitoring device 32 of the seating monitoring system 30 to send and receive various data. The wireless device 25 complies with wireless communication standards such as Wi-Fi, Bluetooth (registered trademark), and EnOcean. The wireless device 25 transmits the determination result of the sensor device 20 to the monitoring device 32.

[0022] The monitoring device 32 is capable of wireless communication with the wireless devices 25 mounted on the sensor boards 14 of the multiple seating detection devices 10. The monitoring device 32 has a display unit (not shown) that displays data received from the seating detection devices 10. The monitoring device 32 receives determination results regarding the presence or absence of seating from the multiple seating detection devices 10.

[0023] For example, if this seating monitoring system 30 is used in a movie theater or a theater, the monitoring device 32 can display the positions of occupied and vacant seats among all the seats, allowing the operator of the monitoring device 32 to determine if someone is sitting in a seat that has not been sold.

[0024] An example of a method of using the seating detection device 10 will be described below with reference to the flowchart of FIG. 4 and FIG. When starting to use the seating detection device 10, the user first attaches the seating detection device 10 to the underside of the seat 101 of the chair 100 that is the detection target. At this time, the adhesive sheet 16 is brought into contact with the underside of the seat 101 of the chair 100 to attach the seating detection device 10. The position at which the seating detection device 10 is fixed to the chair 100 is not limited to the underside of the seat 101, and the seating detection device 10 may also be fixed to the backrest 102 or armrest 103.

[0025] After fixing the seating detection device 10 to the chair 100, the user turns on the switch 23 of the seating detection device 10. At this time, it is assumed that the user turns on the switch 23 while sitting in the chair 100, and also while not sitting in the chair. Here, first, a case where the user turns on the switch 23 of the seating detection device 10 while not sitting in the chair 100 will be described.

[0026] 4, when the user turns on the switch 23, the processor 21 of the sensor device 20 determines that the switch 23 has been turned on (ACT1; YES). When the switch 23 is turned on, the processor 21 supplies power from the power supply 24 to the sensor substrate 14, and an electric field is formed via the electrodes of the sensor substrate 14.

[0027] In this state, the processor 21 starts detecting capacitance in ACT2. Then, the processor 21 stores the capacitance detected in ACT2 in the memory 22. As described above, the capacitance detected by the processor 21 changes depending on whether or not the user is seated. An example of the change over time in the capacitance stored in the memory 22 is shown in FIG. 5.

[0028] The capacitance detected by the processor 21 of the sensor device 20 increases as the dielectric approaches the sensor substrate 14. Therefore, when a user sits on the chair 100, part of the user's body enters the electric field formed by the electrodes of the sensor substrate 14, causing the capacitance to increase rapidly. The change in capacitance shown in Figure 5 indicates whether the user is seated, and indicates that the user is seated during periods when the capacitance is increasing.

[0029] In ACT2, the processor 21 starts detecting capacitance at time T s Since the user is not sitting on chair 100 in ACT2, the initial value of capacitance detected by processor 21 in ACT2 is offset capacitance O when the user is not sitting. This offset capacitance O is a value determined depending on the thickness and material of seat 101 of chair 100, the shape of the electrodes of seating detection device 10, the shape and layout of peripheral components such as case 12, and the ambient temperature and other environmental factors. Note that offset capacitance O is the value of capacitance detected by processor 21 when the user turns on switch 23, and if a capacitance lower than offset capacitance O is detected, processor 21 updates offset capacitance O to the smaller value.

[0030] After starting to detect capacitance in ACT2, the processor 21 determines the capacitance threshold S b A tentative threshold S for setting a Set the tentative threshold S a is the threshold S used in the seating monitoring mode described later. b Lower. Temporary threshold S a is the threshold S bIn order to detect the trial sitting of the user for setting the threshold S with higher sensitivity than usual, it is desirable to set the threshold S to a value slightly larger than the offset capacitance O. For example, in ACT 3, the processor 21 sets the value obtained by adding a predetermined fixed value to the offset capacitance O as the provisional threshold S. a and stores it in the memory 22.

[0031] Processor 21 sets the tentative threshold S in ACT3. a After setting the threshold value S, the system waits for the user to sit down for a trial, and in ACT4, the capacitance detected by the sensor device 20 reaches the provisional threshold value S a It is judged whether the threshold S b In order to set the threshold value, the user needs to sit down and leave the seat once. When it is determined in ACT4 that the user has sat down for a trial (ACT4; YES), the processor 21 calculates, in ACT5, the value obtained by subtracting the offset capacitance O from the capacitance detected by the sensor device 20, and calculates the value when the capacitance is equal to or smaller than the provisional threshold value S a Time period W exceeding t and calculate the average value.

[0032] Furthermore, after calculating the average value of the capacitance in ACT5, the processor 21 calculates an appropriate threshold value S derived from this average value in ACT6. b In this embodiment, in ACT6, 60% of the average value is set as the threshold value S b The appropriate threshold value S b is a value that is mainly determined by the electrode shape of the sensor substrate 14, and the appropriate value of the ratio to the average value differs depending on the type of sensor substrate 14. b is preferably set to, for example, 30% to 70% of the average value calculated in ACT5.

[0033] Processor 21 uses the threshold S set in ACT6. b is the threshold S a In addition, the processor 21 stores the threshold value S set in ACT6 in the memory 22 instead of the threshold value S b is transmitted to the monitoring device 32 via the wireless device 25.

[0034] ACT6 threshold S b After setting the threshold S b In ACT7, the system transitions to a seating monitoring mode using the sensor device 20. b In ACT7, the processor 21 determines whether the capacitance exceeds the threshold value S b If it is determined that the capacitance exceeds the threshold value S (ACT7; YES), it is determined that the user is seated on the chair 100 (ACT8). b If it is determined that the seating position does not exceed the seating position (ACT7; NO), it is determined that the user is not seated on the chair 100 (ACT9), and the determination results of ACT8 and ACT9 are transmitted to the monitoring device 32 (ACT10).

[0035] After transmitting the seating determination result to monitoring device 32 in ACT10, processor 21 transitions to power saving mode in ACT11. In power saving mode, processor 21 cuts off the supply of power from power source 24 for a certain period of time (for example, several seconds to several tens of seconds). In other words, after transitioning to power saving mode, if processor 21 determines that a certain period of time has passed (ACT13; YES) without switch 23 being turned off (ACT12; NO), processor 21 transitions to ACT7 and cancels power saving mode.

[0036] Incidentally, when starting to use the seating detection device 10 described above, if the user turns on the switch 23 while sitting in the chair 100, the processor 21 of the sensor device 20 temporarily stores the capacitance detected while the user is seated in the chair 100 in the memory 22 as the offset capacitance O. In this case, if the user subsequently leaves the seat, the detected capacitance will decrease, and at this point, the processor 21 overwrites the value of the decreased capacitance in the memory 22 as a new offset capacitance O. After this, the processor 21 proceeds to ACT3 and continues processing based on the updated offset capacitance O.

[0037] As described above, according to this embodiment, by attaching the seating detection device 10 to the chair 100 that is the target of seating detection and turning on the switch 23, the threshold value S suitable for the chair 100 can be obtained. b Therefore, the seating detection device 10 of this embodiment can optimize the detection sensitivity according to the characteristics of the chair 100 to which it is attached, and can be attached to and used on existing chairs made of different materials and with different structures.

[0038] The seating detection device 10 may be provided with an LED lamp or the like that is lit from when the switch 23 is turned on until the setting of the threshold value Sb is completed in ACT6. The LED lamp may be lit, for example, while detecting that a user is "sitting" on the chair 100, and turned off when the user is "leaving the chair."

[0039] FIG. 6 is a perspective view showing an external appearance of a modified example of the seating detection device 10 described above. The seating detection device 40 according to the modified example has a mode changeover switch 42 instead of the switch 23. The seating detection device 40 also has a sensitivity adjustment knob 44 for adjusting the threshold value and an LED lamp 46. Other configurations are substantially the same as those of the seating detection device 10 described above, and therefore, a description of configurations that function in the same way will be omitted.

[0040] The mode changeover switch 42 can be switched to any one of a position for selecting an adjustment mode for adjusting the threshold value for seating detection, a position for selecting a seating monitoring mode, and an OFF position for cutting off the power supply.

[0041] In the seating detection device 40 of this modified example, the threshold value S b When setting the threshold value S, the user installs the seating detection device 40 on the chair 100 and then switches the mode changeover switch 42 from the OFF position to the adjustment mode position. When the mode changeover switch 42 is switched to the adjustment mode position, the processor 21 of the sensor device 20 refers to the value of the sensitivity adjustment knob 44 and sets this value as the threshold value S bThen, the processor 21 forms an electric field via the electrodes of the sensor substrate 14 and detects the capacitance.

[0042] In this state, the user repeatedly sits on and leaves the chair 100. Then, the processor 21 detects whether the capacitance exceeds the threshold value S b If the capacitance exceeds the threshold value S, it is determined that the person is seated and the LED lamp 46 is turned on. b If the time is less than the predetermined time, it is determined that the user is "away" and the LED lamp 46 is turned off.

[0043] The user repeatedly sits and leaves the seat while watching the LED lamp 46 to determine whether the seat detection device 40 is correctly detecting "sitting" and "leaving the seat" and then operates the sensitivity adjustment knob 44 to adjust the threshold value S b Adjust to an appropriate value.

[0044] Threshold S b After adjusting the threshold value S, the user switches the mode changeover switch 42 from the adjustment mode position to the seating monitoring mode position. After this, the processor 21 adjusts the threshold value S to an appropriate value using the sensitivity adjustment knob 44. b Based on this, the system determines whether the user is "seated" or "away from the seat" and transmits the determination result to the monitoring device 32 of the seating monitoring system 30.

[0045] As described above, in the seating detection device 40 according to the modified example, the threshold value S b can be adjusted, and the detection sensitivity of seating can be set to any value. Therefore, the seating detection device 40 according to the modified example can also achieve the same effect as the seating detection device 10 described above. In other words, even in the modified example, the detection sensitivity of "seating" can be optimized to match the characteristics of the chair 100 to which it is to be attached, and the seating detection device 40 can be attached and used on existing chairs of different materials and structures. Furthermore, with the seating detection device 40 of this modified example, even if there are differences in sensitivity due to the physique or age of the user sitting on the chair 100, the threshold value S b This allows for fine adjustment of the sensor, enabling more accurate detection of whether the person is seated.

[0046] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. The inventions described in the claims of the present application as originally filed are as follows: [1] a detection unit that forms an electric field and detects a change in capacitance; a fixing part for fixing the detection part to a chair; a power source that supplies power to the detection unit to form the electric field; a switch for turning on / off the power supply from the power source to the detection unit; a determination unit that, after the switch is turned on, detects a change in capacitance via the detection unit, sets an appropriate threshold value based on the amount of change, and determines whether or not an occupant is seated based on the threshold value; A seating detection device having the same. [2] the determination unit sets a provisional threshold value greater than the capacitance detected via the detection unit when no one is sitting on the chair, calculates an average value of the capacitances detected via the detection unit that exceed the provisional threshold value, and sets the appropriate threshold value from this average value. [1] The seating detection device described in [1]. [3] a detection unit that forms an electric field and detects a change in capacitance; a fixing part for fixing the detection part to a chair; a power source that supplies power to the detection unit to form the electric field; an adjustment unit that adjusts a threshold value that is a criterion for determining whether or not an occupant is seated on the chair; a determination unit that determines whether or not an occupant is seated based on the threshold value adjusted by the adjustment unit, based on the change in capacitance detected by the detection unit; A seating detection device having the same. [4] [1] The seating detection device according to the present invention; a monitoring device that receives and displays the determination result from the determination unit; A seating monitoring system having: [5] [3] The seating detection device according to the present invention; a monitoring device that receives and displays the determination result from the determination unit; A seating monitoring system having: [Explanation of symbols]

[0047] 10... seating detection device, 12... case, 14... sensor board, 16... adhesive sheet, 18... spacer, 20... sensor device, 21... processor, 22... memory, 23... switch, 24... power supply, 25... wireless device, 30... seating monitoring system, 32... monitoring device, 40... seating detection device, 42... mode switching switch, 44... sensitivity adjustment knob, 46... LED lamp, S b ...threshold.

Claims

1. a detection unit that forms an electric field and detects a change in capacitance; a fixing part for fixing the detection part to a chair; a power source that supplies power to the detection unit to form the electric field; a switch that turns on / off the power supply from the power source to the detection unit; a determination unit that, after the switch is turned on, detects a change in capacitance via the detection unit, sets an appropriate threshold value based on the amount of change, and determines whether or not an occupant is seated based on the threshold value; the determination unit sets a provisional threshold value greater than the capacitance detected via the detection unit when no one is sitting on the chair, calculates an average value of the capacitances detected via the detection unit that exceed the provisional threshold value, and sets the appropriate threshold value from this average value. Occupancy detection device.

2. The seating detection device according to claim 1 ; a monitoring device that receives and displays the determination result from the determination unit; A seating monitoring system having:

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