Equipment state monitoring system

Abstract

The control unit performs: a first abnormality determination for comparing the detection signal with a first threshold range for ascertaining the state of the device, and determining that the detection signal is abnormal when the detection signal is outside the first threshold range; and a second abnormality determination in which a characteristic signal indicating a characteristic of the sensor device is compared with a second threshold range for ascertaining a state of the sensor device when an abnormality is determined in the first abnormality determination, and when the characteristic signal is outside the second threshold range, it is determined that the characteristic signal is abnormal and an abnormality has occurred in the sensor device.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese Patent Application No. 2022-184237 filed on November 17, 2022, the contents of which are incorporated herein by reference. Technical field

[0003] The present disclosure relates to a device state monitoring system for detecting abnormalities in a device. Background art

[0004] Conventionally, a piezoelectric device in which a piezoelectric element is disposed in a housing has been proposed (for example, refer to Patent Document 1). Specifically, the piezoelectric element is configured to have a vibration region and transmit a detection signal corresponding to the sound pressure applied to the vibration region. Further, a piezoelectric device as described above is mounted on a processing device, a conveying device, etc. which are devices so that the sound pressure generated according to the state of the device is applied to the vibration region.

[0005] Prior art documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 7156558 Gazette Summary of the invention

[0008] In the case of mounting the piezoelectric device as described above on a device to detect an abnormality of the device, for example, a control unit connected to the piezoelectric element is provided, and the abnormality of the device is determined based on the detection signal by the control unit. In this case, the control unit compares the detection signal with a specified threshold range, and if the detection signal is outside the threshold range, it is determined that an abnormality has occurred in the device.

[0009] However, the detection signal may be outside the threshold range due to an abnormality occurring in the piezoelectric device itself. Therefore, in such an abnormality determination, it is possible to erroneously determine that an abnormality has occurred even though the device has not actually malfunctioned.

[0010] An object of the present disclosure is to provide a device state monitoring system capable of suppressing false determination.

[0011] According to one aspect of the present disclosure, a device state monitoring system includes: a sensor device having a sensor element that transmits a detection signal corresponding to the state of a device; and a control unit that performs a prescribed process based on the detection signal. The control unit performs: a first abnormality determination that compares the detection signal with a first threshold range for grasping the state of the device and determines that the detection signal is abnormal when the detection signal is outside the first threshold range; and a second abnormality determination that, when the first abnormality determination determines that it is abnormal, compares a characteristic signal indicating the characteristics of the sensor device with a second threshold range for grasping the state of the sensor device and determines that the characteristic signal is abnormal and that an abnormality has occurred in the sensor device when the characteristic signal is outside the second threshold range.

[0012] Thus, when the detection signal is outside the first threshold range, a second abnormality determination is made as to whether the characteristic signal based on the characteristics of the sensor device is within the second threshold range. Therefore, it is possible to suppress the situation where it is determined that there is an abnormality in the device even though there is an abnormality in the sensor device, and it is possible to suppress the situation of misjudging that there is an abnormality in the device.

[0013] In addition, the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and the specific components etc. described in the embodiments described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a block diagram of the device state monitoring system in the first embodiment.

[0015] Figure 2 is a cross-sectional view of a piezoelectric element.

[0016] Figure 3 is a top view of the piezoelectric element.

[0017] Figure 4 is a cross-sectional view of a piezoelectric device.

[0018] Figure 5 is a flowchart executed by the first determination unit.

[0019] Figure 6 is a flowchart executed by the second determination unit.

[0020] Figure 7 is a block diagram of the device state monitoring system in a modification of the first embodiment.

[0021] Figure 8 is a block diagram of the device state monitoring system in the second embodiment.

[0022] Figure 9 is a top view of the piezoelectric element.

[0023] Figure 10It is a cross-sectional view of a piezoelectric device.

[0024] Figure 11 It is a flowchart executed by the second determination unit.

[0025] Figure 12 It is a cross-sectional view of a piezoelectric device in a modified example of the second embodiment.

[0026] Figure 13 It is a block diagram of an equipment state monitoring system in the third embodiment.

[0027] Figure 14 It is a flowchart executed by the second determination unit. Detailed implementation manners

[0028] Hereinafter, embodiments of the present disclosure will be described based on the accompanying drawings. In addition, in the following embodiments, the same or equivalent parts are denoted by the same reference numerals for description.

[0029] (First Embodiment)

[0030] The first embodiment will be described with reference to the accompanying drawings. In addition, the equipment state monitoring system of the present embodiment is preferably equipped in equipment for manufacturing a specified manufactured product to detect abnormalities of the equipment. For example, the equipment state monitoring system of the present embodiment is equipped in a processing equipment having a tool to detect abnormalities such as wear and breakage of the tool. However, the equipment to be the determination object can be appropriately changed, and it can also be a conveying equipment or the like.

[0031] As Figure 1 shown, the equipment state monitoring system S1 is configured to include a circuit unit 20 having a piezoelectric element 10 and a control unit 210, etc. In addition, in the present embodiment, the piezoelectric element 10 and the circuit unit 20 are arranged together in a housing 300 described later to form an integrated piezoelectric device S10. In addition, in the present embodiment, the piezoelectric element 10 corresponds to a sensor element.

[0032] The piezoelectric device S10 (that is, the piezoelectric element 10) is equipped in the equipment 30 and outputs a detection signal corresponding to the sound pressure generated by the equipment 30. In addition, as described above, the equipment 30 of the present embodiment is a processing equipment having a tool.

[0033] Hereinafter, with reference to Figure 2 and Figure 3The piezoelectric element 10 of the present embodiment will be described. The piezoelectric element 10 includes a support 110 and a vibrating portion 120, and has a rectangular planar shape. The support 110 includes a support substrate 111 having one surface 111a and the other surface 111b, and an insulating film 112 formed on the one surface 111a of the support substrate 111. In addition, the support substrate 111 is made of, for example, a silicon substrate, and the insulating film 112 is made of an oxide film or the like.

[0034] The vibrating portion 120 is disposed on the support 110. Moreover, a recess 110a for suspending the inner edge side of the vibrating portion 120 is formed in the support 110. Therefore, the vibrating portion 120 has a configuration including a support region 121a disposed on the support 110 and a suspended region 121b connected to the support region 121a and suspended on the recess 110a. In addition, the shape of the open end on the vibrating portion 120 side of the recess 110a in the present embodiment is a planar rectangular shape. Therefore, the entire suspended region 121b is a planar rectangular shape.

[0035] A slit 130 penetrating the suspended region 121b in the thickness direction is formed in the suspended region 121b. The slit 130 in the present embodiment is formed so as to divide the suspended region 121b into four parts. Specifically, two slits 130 are formed so as to pass through the central portion C1 of the suspended region 121b and extend toward the opposite corner portions of the suspended region 121b. In other words, the slits 130 are formed to extend from the respective corner portions of the suspended region 121b having a planar rectangular shape toward the central portion C1, and the respective slits 130 intersect at the central portion C1. As a result, the suspended region 121b is separated into four vibrating regions 122 having a substantially planar triangular shape. Although not particularly limited, in the present embodiment, the interval between the respective vibrating regions 122 (that is, the width of the slit 130) is set to about 1 μm.

[0036] Moreover, each vibrating region 122 is formed as a cantilever, the end portion on the support region 121a side is a fixed end, and the front end portion on the side opposite to the support region 121a is a free end. Hereinafter, the surface of the vibrating region 122 opposite to the support 110 will be referred to as one surface 122a of the vibrating region 122, and the surface of the vibrating region 122 on the support 110 side will be referred to as the other surface 122b of the vibrating region 122 for description.

[0037] The vibrating portion 120 is configured to include a piezoelectric film 140 and an electrode film 150 connected to the piezoelectric film 140. Specifically, the piezoelectric film 140 includes a lower piezoelectric film 141 and an upper piezoelectric film 142 laminated on the lower piezoelectric film 141. In addition, the lower piezoelectric film 141 and the upper piezoelectric film 142 are made of lead-free piezoelectric ceramics such as scandium aluminum nitride (ScAlN) and aluminum nitride (AlN).

[0038] The electrode film 150 is formed at a specified position in the vibration region 122 in a manner connected to the piezoelectric film 140, and is made of molybdenum, copper, platinum, platinum, titanium, etc. In the present embodiment, as the electrode film 150, a lower electrode film 151 formed under the lower piezoelectric film 141, an intermediate electrode film 152 formed between the lower piezoelectric film 141 and the upper piezoelectric film 142, and an upper electrode film 153 formed above the upper piezoelectric film 142 are formed. In addition, the lower electrode film 151 and the intermediate electrode film 152 are arranged to face each other with the lower piezoelectric film 141 interposed therebetween. The intermediate electrode film 152 and the upper electrode film 153 are arranged to face each other with the upper piezoelectric film 142 interposed therebetween. And, the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 are set to have the same shape in the normal direction with respect to the surface 122a of the vibration region 122 (hereinafter also simply referred to as the normal direction). In addition, the so-called normal direction with respect to the surface 122a of the vibration region 122, in other words, can also be said to be when viewed from the normal direction of the surface 122a of the vibration region 122.

[0039] Here, in the case where the vibration region 122 is cantilever-supported as described above, regarding the stress generated when the vibration region 122 (that is, the piezoelectric film 140) vibrates, the fixed-end side that supports the vibration region 122 tends to become larger than the free-end side. Therefore, the vibration region 122 is divided into a first region R1 where the stress easily becomes larger and a second region R2 where the stress easily becomes smaller. And, in the present embodiment, the electrode film 150 is formed in each of the first region R1 and the second region R2. In addition, the electrode film 150 formed in the first region R1 and the electrode film 150 formed in the second region R2 are in a mutually insulated state.

[0040] Moreover, although not particularly illustrated, the electrode film 150 formed in the first region R1 is connected to an electrode portion (not shown) via wirings formed in the support region 121a. In the present embodiment, each of the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 in each vibration region 122 is connected to the electrode portion so as to output the change in charge in the first region R1 of each vibration region 122 as one detection signal.

[0041] In addition, the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 formed in the second region R2 are not electrically connected to the respective electrode portions and are in a floating state. Therefore, the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 formed in the second region R2 are not necessarily required, but in the present embodiment, they are provided to protect the portions of the lower piezoelectric film 141 and the upper piezoelectric film 142 located in the second region R2.

[0042] In addition, the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 formed in the first region R1 and the second region R2 are respectively formed so as not to reach the slit 130. That is, the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 are formed to terminate at a position inside the side surface exposed from the slit 130 in the vibration region 122. In other words, the lower electrode film 151, the intermediate electrode film 152, and the upper electrode film 153 are arranged inside the slit 130 in the normal direction of the surface 122a of the vibration region 122.

[0043] Furthermore, the vibration part 120 of the present embodiment has a base film 160 on which the lower piezoelectric film 141 and the lower electrode film 151 are arranged. That is, the piezoelectric film 140 and the electrode film 150 are arranged on the support 110 with the base film 160 interposed therebetween. Moreover, in the present embodiment, the other surface 122b of each vibration region 122 is constituted by the base film 160.

[0044] The base film 160 is not essential, but is provided to facilitate crystal growth when forming the lower piezoelectric film 141 and the like. In addition, in the present embodiment, the base film 160 is made of aluminum nitride or the like. In addition, the thickness of the piezoelectric film 140 is about 1 μm, and the thickness of the base film 160 is about several tens of nm. That is, the base film 160 is extremely thin relative to the piezoelectric film 140.

[0045] The above is the configuration of the piezoelectric element 10 in the present embodiment. When such a piezoelectric element 10 applies a sound pressure to each vibration region 122, each vibration region 122 vibrates. In this case, for example, when the free end side of each vibration region 122 is displaced upward, a tensile stress is generated in the lower piezoelectric film 141 and a compressive stress is generated in the upper piezoelectric film 142, and the charges of the lower piezoelectric film 141 and the upper piezoelectric film 142 change. Therefore, the sound pressure applied to the vibration region 122 is detected based on the charges of the lower piezoelectric film 141 and the upper piezoelectric film 142.

[0046] At this time, the stress generated in the vibration region 122 (that is, the piezoelectric film 140) is released at the free end side, so the stress on the fixed end side is larger than that on the free end side. That is, the generation of charges on the free end side becomes less, and the signal-to-noise ratio, that is, the SN ratio, is likely to become smaller. Therefore, in the piezoelectric element 10 of the present embodiment, as described above, each vibration region 122 is divided into a first region R1 where the stress is likely to increase and a second region R2 where the stress is likely to decrease. Moreover, in the piezoelectric element 10, the charges generated in the lower piezoelectric film 141 and the upper piezoelectric film 142 located in the first region R1 are taken out from the lower electrode film 151, the upper electrode film 153, and the intermediate electrode film 152 arranged in the first region R1. Thereby, the influence of noise can be suppressed from becoming large.

[0047] AsFigure 1 As shown, the circuit unit 20 is configured to include an amplification unit 200, a control unit 210, and the like.

[0048] Moreover, in the present embodiment, as Figure 4 shown, the piezoelectric element 10 and the circuit unit 20 are both housed in the housing 300 to form the piezoelectric device S10. Specifically, the housing 300 has a printed circuit board 310 on which the piezoelectric element 10 and the circuit unit 20 are mounted, and a cover portion 320 fixed to the printed circuit board 310 so as to house the piezoelectric element 10 and the circuit unit 20. In addition, the printed circuit board 310 may also be referred to as a mounted component.

[0049] Although not particularly illustrated, the printed circuit board 310 is configured to appropriately form a wiring portion, via-hole electrodes, etc., and also mounts electronic components such as capacitors (not shown) as needed. The other surface 111b of the support substrate 111 of the piezoelectric element 10 is mounted on one surface 310a of the printed circuit board 310 via a bonding member such as an adhesive. And, in the present embodiment, a through-hole 311 is formed in a portion of the printed circuit board 310 that faces the vibration region 122.

[0050] The circuit unit 20 is mounted on one surface 310a of the printed circuit board 310 via a bonding member 340 formed of a conductive member. Moreover, the piezoelectric element 10 and the circuit unit 20 are electrically connected via a bonding wire 301. The cover portion 320 is made of metal, plastic, resin, etc., and is fixed to the printed circuit board 310 via a bonding member (not shown) so as to house the piezoelectric element 10 and the circuit unit 20.

[0051] Such a piezoelectric device S10 is configured such that the sound pressure generated from the device 30 is applied to the vibration region 122 via the through-hole 311. Moreover, the piezoelectric element 10 transmits a detection signal corresponding to the sound pressure (i.e., pressure) introduced from the through-hole 311 to the circuit unit 20.

[0052] Next, the configuration of the circuit unit 20 of the present embodiment will be specifically described. As described above, the circuit unit 20 has a configuration including an amplification unit 200, a control unit 210, and the like.

[0053] When the amplification unit 200 receives the detection signal from the piezoelectric element 10, it amplifies the detection signal and sends it to the control unit 210 and the external circuit unit 40.

[0054] The control unit 210 includes a microcomputer or the like having a CPU, a storage unit composed of non-transitory physical storage media such as a ROM, a RAM, a flash memory, and an HDD, and has a determination unit 220 and a characteristic acquisition unit 230. The CPU is an abbreviation for Central Processing Unit, the ROM is an abbreviation for Read Only Memory, the RAM is an abbreviation for Random Access Memory, and the HDD is an abbreviation for Hard Disk Drive. The storage media such as the ROM are non-transitory physical storage media.

[0055] The determination unit 220 of the present embodiment has a first determination unit 221 and a second determination unit 222. The first determination unit 221 performs a first abnormality determination for comparing the amplified detection signal with a specified first threshold range. Specifically, if the detection signal is within the first threshold range, the first determination unit 221 determines that the detection signal is normal, and if the detection signal is outside the first threshold range, the first determination unit 221 determines that the detection signal is abnormal. For example, in the case of detecting the state of a tool in the detection device 30, when the wear of the tool increases, the sound pressure introduced from the through hole 311 increases. Therefore, the first determination unit 221 determines that the detection signal is abnormal when the detection signal increases and becomes outside the first threshold range. Further, when the first determination unit 221 determines that the detection signal is abnormal, it sends a characteristic determination signal to the second determination unit 222. In addition, when the first determination unit 221 determines that the detection signal is within the first threshold range, since the device 30 is normal, it sends a normal signal to the external circuit unit 40. Further, the first threshold range is a range for grasping the state of the device, and is appropriately set based on, for example, the material and shape of the tool so as to be able to detect the wear of the tool.

[0056] When the second determination unit 222 receives the characteristic determination signal from the first determination unit 221, it sends a characteristic acquisition signal to the characteristic acquisition unit 230. Then, when the second determination unit 222 receives the characteristic signal from the characteristic acquisition unit 230 as described later, it performs a second abnormality determination of comparing the characteristic signal with the second threshold range. Specifically, if the characteristic signal is within the second threshold range, the second determination unit 222 determines that the characteristic signal is normal, and if the characteristic signal is outside the second threshold range, the second determination unit 222 determines that the characteristic signal is abnormal. More specifically, if the characteristic signal is within the second threshold range, the second determination unit 222 determines that the piezoelectric device S10 is normal and the device 30 is abnormal, and if the characteristic signal is outside the second threshold range, the second determination unit 222 determines that the piezoelectric device S10 is abnormal and the device 30 is normal. That is, the second determination unit 222 performs self-diagnosis of the piezoelectric device S10. For example, in the piezoelectric element 10 as described above, when foreign matter adheres to the vibration region 122 or the vibration region 122 is damaged, etc., the mass increases, so the resonance frequency changes. Therefore, if the characteristic signal based on the resonance frequency changes and is outside the second threshold range, the second determination unit 222 determines that it is abnormal. In addition, the second threshold range is a range for grasping the state of the piezoelectric device S10 and is appropriately set based on the sensitivity of the vibration region 122 and the like.

[0057] Moreover, when the second determination unit 222 determines that the piezoelectric device S10 is normal, it sends a device abnormality signal indicating that the device 30 is abnormal to the external circuit unit 40. In addition, when the second determination unit 222 determines that the piezoelectric device S10 is abnormal, it sends a piezoelectric device abnormality signal indicating that the piezoelectric device S10 is abnormal to the external circuit unit 40.

[0058] In the present embodiment, the characteristic acquisition unit 230 is configured to include an RLC circuit having a resistor, a coil, a capacitor, etc. Moreover, when the characteristic acquisition unit 230 receives the characteristic acquisition signal from the second determination unit 222, it sends a characteristic signal indicating the characteristic of the piezoelectric element 10. In the present embodiment, the characteristic acquisition unit 230 sends the characteristic signal based on the resonance frequency of the vibration region 122 in the piezoelectric element 10 to the second determination unit 222. In addition, as described above, the characteristic signal based on the resonance frequency of the vibration region 122 changes when foreign matter adheres to the vibration region 122 or the vibration region 122 is damaged.

[0059] The external circuit unit 40 performs prescribed processing according to the received signal. For example, the external circuit unit 40 is connected to a display device or the like that can be visually confirmed by an operator, and causes the display device to display the states of the device 30 and the piezoelectric device S10.

[0060] Specifically, when the external circuit unit 40 receives a normal signal from the first determination unit 221, it displays the content that the display device 30 and the piezoelectric device S10 are normal. On the other hand, when the external circuit unit 40 receives a device abnormality signal from the second determination unit 222, it causes the display device to display the content that an abnormality has occurred in the device 30. In addition, when the external circuit unit 40 receives a piezoelectric device abnormality signal from the second determination unit 222, it causes the display device to display the content that an abnormality has occurred in the piezoelectric device S10.

[0061] The above is the configuration of the device status monitoring system in this embodiment. Next, the operations performed by the control unit 210 will be described. First, refer to Figure 5 The operation of the first determination unit 221 will be described.

[0062] The first determination unit 221 receives the amplified detection signal from the amplifier unit 200 in step S101. Next, the first determination unit 221 determines whether it is the determination timing in step S102. For example, the determination timing is set to the start of operation of the device 30, the end of operation, or each specified timing. However, the determination timing of the first determination unit 221 can be appropriately changed. Then, when the first determination unit 221 determines that it is not the determination timing (i.e., step S102: NO), the process ends directly.

[0063] When the first determination unit 221 determines that it is the determination timing (i.e., step S102: YES), in step S103, it performs a first abnormality determination by comparing the detection signal with the first threshold range. Then, when the first determination unit 221 determines that the detection signal is within the first threshold range and there is no abnormality in the detection signal (i.e., step S103: NO), in step S104, it sends a normal signal to the external circuit unit 40 and ends the process. On the other hand, when the first determination unit 221 determines that the detection signal is outside the first threshold range and there is an abnormality in the detection signal (i.e., step S103: YES), in step S105, it sends a characteristic determination signal to the second determination unit 222 and ends the process.

[0064] The above is the operation of the first determination unit 221. Next, refer to Figure 6 The operation of the second determination unit 222 will be described.

[0065] The second determination unit 222 determines in step S201 whether a characteristic determination signal has been received. If it is determined that the characteristic determination signal has not been received (i.e., step S201: NO), the process ends. When the second determination unit 222 determines that the characteristic determination signal has been received (i.e., step S201: YES), it sends a characteristic acquisition signal to the characteristic acquisition unit 230 in step S202. Thereby, the characteristic acquisition unit 230 sends a characteristic signal based on the resonance frequency of the vibration region 122 in the piezoelectric element 10 to the second determination unit 222. Additionally, as described above, the characteristic signal based on the vibration region 122 changes when a foreign object adheres to the vibration region 122 or the vibration region 122 is damaged, etc.

[0066] Next, the second determination unit 222 determines in step S203 whether a characteristic signal has been received. If it is determined that the characteristic signal has not been received (i.e., step S203: NO), the process of step S203 is executed again. That is, the second determination unit 222 stands by until a characteristic signal is received.

[0067] When the second determination unit 222 determines that the characteristic signal has been received (i.e., step S203: YES), in step S204, a second abnormality determination is performed to compare the characteristic signal with a second threshold range. That is, self-diagnosis of the piezoelectric device S10 is performed. Then, when the second determination unit 222 determines that the characteristic signal is not within the second threshold range (i.e., step S204: YES), since the characteristic signal is abnormal, a piezoelectric device abnormality signal indicating that the piezoelectric device S10 is abnormal is sent to the external circuit unit 40 in step S205. On the other hand, when the second determination unit 222 determines that the characteristic signal is within the second threshold range (i.e., step S204: NO), since the characteristic signal is normal, it is determined that there is an abnormality in the device 30, and a device abnormality signal indicating that there is an abnormality in the device 30 is sent to the external circuit unit 40 in step S206.

[0068] According to the present embodiment described above, when the detection signal is outside the first threshold range, a second abnormality determination is performed to determine whether the characteristic signal based on the characteristics of the piezoelectric device S10 is within the second threshold range. Therefore, it is possible to suppress the situation where it is determined that there is an abnormality in the device 30 although there is an abnormality in the piezoelectric device S10. That is, it is possible to suppress the misjudgment that there is an abnormality in the device 30.

[0069] (Modification of the First Embodiment)

[0070] A modification of the first embodiment will be described. In the above first embodiment, as Figure 7As shown, it may also include a characteristic operation unit 240 composed of a sound source that generates sound pressure or the like and connected to the characteristic acquisition unit 230. In addition, the characteristic operation unit 240 is configured to be able to generate sound pressures of multiple different frequencies so as to be able to cope with the resonance frequencies in the vibration region 122. In this case, the characteristic acquisition unit 230 is configured to, when receiving a characteristic acquisition signal, derive a characteristic signal based on the resonance frequency of the piezoelectric element 10 based on the detection signal generated by operating the characteristic operation unit 240, and send the derived characteristic signal to the second determination unit 222. In this way, the resonance frequency as the characteristic signal can also be mechanically obtained.

[0071] (Second Embodiment)

[0072] The second embodiment will be described. This embodiment performs a recovery operation with respect to the first embodiment. Since the others are the same as the first embodiment, the description thereof is omitted here.

[0073] In this embodiment, as Figure 8 shown, the device state monitoring system S1 further includes a component recovery unit 250, a housing recovery unit 260, and a recovery operation unit 270.

[0074] Specifically, as Figure 9 shown, in this embodiment of the piezoelectric element 10, a temperature detection element 251 that outputs a temperature detection signal corresponding to the temperature and a heating element 252 that generates heat when energized are arranged in each vibration region 122 as the component recovery unit 250. In this embodiment, the temperature detection element 251 and the heating element 252 are formed in the second region R2 of each vibration region 122. More specifically, in this embodiment, the intermediate electrode film 152 is not formed in the second region R2. And the temperature detection element 251 and the heating element 252 are formed in a portion between the lower piezoelectric film 141 and the upper piezoelectric film 142. That is, the temperature detection element 251 and the heating element 252 are formed in the portion where the intermediate electrode film 152 is formed in the above first embodiment.

[0075] In addition, the temperature detection element 251 is constituted by, for example, a thermistor whose resistance value changes according to the temperature, and the heating element 252 is constituted by, for example, a heating resistor that generates heat when energized. In this embodiment, the temperature detection element 251 and the heating element 252 are made of platinum, for example.

[0076] Furthermore, in the housing 300, as Figure 10 shown, as the housing recovery unit 260, it includes a temperature detection unit 261, a heating unit 262, and a vibration unit 263.

[0077] The heating part 262 is constituted by, for example, a resistance heating type heater or the like. The temperature detection part 261 is constituted by a thermistor or the like. The vibration part 263 is constituted by a piezoelectric element or the like. Moreover, although not shown in the figure, the temperature detection part 261, the heating part 262, and the vibration part 263 are respectively electrically connected to the circuit part 20 via a wire or the like.

[0078] In addition, in Figure 10 an example is shown in which the vibration part 263 is arranged inside the housing 300, and the temperature detection part 261 and the heating part 262 are arranged outside the housing 300. However, the arrangement locations thereof are not particularly limited, and the vibration part 263 may also be arranged outside the housing 300, and the temperature detection part 261 and the heating part 262 may also be arranged inside the housing 300.

[0079] The restoration operation part 270 is connected to the element restoration part 250 and the housing restoration part 260, and if it receives a restoration start signal from the second determination part 222 as described later, it causes the element restoration part 250 and the housing restoration part 260 to operate.

[0080] Specifically, the restoration operation part 270 controls the temperature detection element 251 and the heating element 252 of the piezoelectric element 10 to make the temperature of the temperature detection element 251 (i.e., the piezoelectric element 10) a specified temperature. Thereby, in the case where foreign matters such as water adhere to the vibration region 122, the foreign matters such as water can be evaporated. In addition, the restoration operation part 270 applies a specified voltage to the piezoelectric element 10 to vibrate the vibration region 122. Thereby, in the case where foreign matters or the like adhere to the vibration region 122, the foreign matters can be shaken off. In addition, in the present embodiment, the object of the element restoration part 250 is the piezoelectric element 10.

[0081] Similarly, the restoration operation part 270 controls the temperature detection part 261 and the heating part 262 arranged in the housing 300 to make the temperature of the temperature detection part 261 (i.e., the housing 300) a specified temperature. Thereby, in the case where foreign matters such as water adhere to the housing 300, the foreign matters such as water can be evaporated. In addition, the restoration operation part 270 applies a specified voltage to the vibration part 263 arranged in the housing 300 to vibrate the housing 300. Thereby, in the case where foreign matters such as water adhere to the housing 300, the foreign matters such as water can be shaken off. In addition, the foreign matters adhering to the housing 300, especially if they adhere to the through hole 311 of the housing 300, the introduced sound pressure changes, so the influence on the detection signal becomes larger. In addition, in the present embodiment, the object of the housing restoration part is the housing 300.

[0082] When the second determination unit 222 receives the characteristic determination signal, it sends a recovery start signal to the recovery operation unit 270. Thereby, the recovery operation unit 270 performs the above operations. Then, the second determination unit 222 performs a second abnormality determination that compares the characteristic signal after the recovery process with the second threshold range.

[0083] The above is the configuration of the device status monitoring system S1 in this embodiment. Next, with reference to Figure 11 The operation of the second determination unit 222 in this embodiment will be described. In addition, the description of the same parts as those in the first embodiment above will be omitted.

[0084] If the second determination unit 222 determines in step S201 that it has received the characteristic determination signal (i.e., S201: YES), then in step S210, it sends a recovery start signal to the recovery operation unit 270. Thereby, the recovery operation unit 270 operates the element recovery unit 250 and the housing recovery unit 260 to perform the work of removing foreign substances when foreign substances are attached.

[0085] After that, in step S211, it is determined whether a specified recovery time has elapsed. That is, it is determined whether the recovery operation is completed. If it is determined that the recovery time has not elapsed (i.e., step S211: NO), the process of step S211 is performed again. That is, it waits until the recovery time elapses.

[0086] When the second determination unit 222 determines that the recovery time has elapsed (i.e., step S211: YES), it performs the processes of steps S202 to S206. In this case, in the process of step S204, the characteristic signal after the recovery operation is compared with the second threshold. That is, the characteristic signal with foreign substances and the like attached inhibited is compared with the second threshold. Therefore, the accuracy of the abnormality determination for the characteristic signal can be improved.

[0087] According to the present embodiment described above, when the detection signal is outside the first threshold range, a second abnormality determination is performed to determine whether the characteristic signal based on the characteristics of the piezoelectric device S10 is within the second threshold range. Therefore, the same effect as that of the first embodiment can be obtained.

[0088] (1) In this embodiment, the recovery operation of the piezoelectric device S10 is performed before the second abnormality determination. Therefore, the abnormality caused by foreign substances and the like attached to the piezoelectric device S10 can be eliminated, and furthermore, the situation of misjudging the piezoelectric device S10 as abnormal can be suppressed.

[0089] (Modification of the second embodiment)

[0090] A modification of the above-described second embodiment will be described. In the above-described second embodiment, the second determination unit 222 may also send an adjustment signal for controlling the temperature detection element 251 and the heating element 252 to the recovery operation unit 270 even when the recovery start signal is not sent, so that the vibration region 122 is kept at a specified temperature. Similarly, the second determination unit 222 may also send an adjustment signal for controlling the temperature detection unit 261 and the heating unit 262 to the recovery operation unit 270 even when the recovery start signal is not sent, so that the housing 300 is kept at a specified temperature. As a result, the detection signal from the piezoelectric element 10 becomes a signal in a state maintained at the specified temperature. Therefore, deviation in detection accuracy can be suppressed.

[0091] In addition, the configurations of the element recovery unit 250 and the housing recovery unit 260 can be appropriately changed. For example, as Figure 12 shown, the housing recovery unit 260 may also include a blower device 264 that applies a specified wind pressure to the through hole 311 of the housing 300. Although not particularly shown, a blower device that applies wind pressure to the piezoelectric element 10 may also be arranged in the housing 300. Moreover, the element recovery unit 250 may be configured to have only the heating element 252 among the temperature detection element 251 and the heating element 252, and the housing recovery unit 260 may be configured to have only the heating unit 262 among the temperature detection unit 261 and the heating unit 262.

[0092] Moreover, in the above-described second embodiment, an example in which the element recovery unit 250 and the housing recovery unit 260 are provided as the recovery unit has been described, but it may also be configured to have only either the element recovery unit 250 or the housing recovery unit 260.

[0093] (Third Embodiment)

[0094] The third embodiment will be described. In this embodiment, the state around the detection device 30 is detected as compared with the first embodiment. Since the rest is the same as the first embodiment, the description thereof is omitted here.

[0095] As Figure 13 shown, the device state monitoring system S1 of this embodiment includes a surrounding temperature detection unit 280 as a surrounding detection unit. The surrounding temperature detection unit 280 is composed of a thermistor or the like and is connected to the second determination unit 222. Moreover, the surrounding temperature detection unit 280 is arranged, for example, near the device 30, and sends a state signal corresponding to the state (i.e., temperature) around the device 30 to the second determination unit 222.

[0096] When the second determination unit 222 receives the characteristic determination signal, it performs a third abnormality determination that compares the status signal with the third threshold range. Specifically, the second determination unit 222 determines that the status signal is normal when the status signal is within the third threshold range, and determines that the status signal is abnormal when the status signal is outside the third threshold range. More specifically, if the status signal is within the third threshold range, the second determination unit 222 determines that the surrounding status of the device 30 is normal, and if the status signal is outside the third threshold range, the second determination unit 222 determines that the surrounding status is abnormal. Moreover, when the second determination unit 222 determines that the status signal is outside the third threshold range, since the surrounding status is abnormal, it sends a surrounding abnormality signal to the external circuit unit 40.

[0097] In addition, the situation where the surrounding status of the device 30 is abnormal means that the device 30, the devices around the device 30, etc. abnormally become high temperature, etc. In addition, the third threshold range is a range for grasping the surrounding status of the device 30. For example, it is set based on the range that the temperature around the device 30 can become during normal use.

[0098] When the external circuit unit 40 receives the surrounding abnormality signal from the second determination unit 222, it causes the display device to display the content that the surrounding temperature of the device 30 is abnormal.

[0099] The above is the configuration of the device status monitoring system S1 in this embodiment. Next, refer to Figure 14 The operation of the second determination unit 222 in this embodiment will be described. In addition, the description of the same parts as in the above first embodiment will be omitted.

[0100] When the second determination unit 222 receives the characteristic determination signal in step S201, it performs a third abnormality determination that compares the status signal with the third threshold range in step S220.

[0101] Then, when the second determination unit 222 determines that the status signal is not within the third threshold range (that is, step S220: YES), since the surrounding status of the device 30 is abnormal, it sends a surrounding abnormality signal to the external circuit unit 40 in step S221. On the other hand, when the second determination unit 222 determines that the status signal is within the third threshold range (that is, step S200: NO), since the surrounding status of the device 30 is normal, it performs the processing of steps S202 to S206.

[0102] According to the present embodiment described above, when the detection signal is outside the first threshold range, a second abnormality determination is performed to determine whether the characteristic signal based on the characteristics of the piezoelectric device S10 is within the second threshold range. Therefore, the same effects as those of the above first embodiment can be obtained.

[0103] (1)In this embodiment, when an abnormality is detected in the detection signal, the surrounding state is determined. Therefore, it is also possible to further suppress misjudgment by considering the influence of the surroundings.

[0104] (Modification of the third embodiment)

[0105] A modification of the above third embodiment will be described. In the above third embodiment, an example in which the ambient temperature detection unit 280 is provided as the ambient detection unit has been described. However, the configuration of the ambient detection unit can be appropriately changed. For example, it can also be composed of a humidity detection unit that detects the humidity of the surroundings, a vibration detection unit that detects the vibration of the surroundings, a sound detection unit that detects the sound of the surroundings, and an illuminance detection unit that detects the illuminance of the surroundings, etc.

[0106] In addition, in the above third embodiment, an example in which the ambient temperature detection unit 280 as the ambient detection unit is arranged around the device 30 has been described. However, the ambient detection unit can also be arranged inside the piezoelectric device S10. In addition, the piezoelectric device S10 outputs a detection signal corresponding to the state of the device 30 and is arranged around the device 30. Therefore, even if the ambient temperature detection unit 280 is arranged inside the piezoelectric device S10, it can be said that the ambient temperature detection unit 280 sends a state signal corresponding to the state of the surroundings of the device 30.

[0107] And in the above third embodiment, an example in which the third abnormality determination is performed before the second abnormality determination has been described, but the third abnormality determination can also be performed after the second abnormality determination.

[0108] (Other embodiments)

[0109] This disclosure has been described based on the embodiments, but it should be understood that this disclosure is not limited to the embodiments and configurations. This disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations, methods, and other combinations and methods that include only one element, more than one, or less than one of them also fall within the scope and ideological scope of this disclosure.

[0110] For example, in the above embodiments, an example in which the control unit 210 has the first determination unit 221 and the second determination unit 222 has been described, but the first determination unit 221 and the second determination unit 222 can also be integrated.

[0111] In addition, in the above embodiments, an example in which the control unit 210 is mounted on the circuit unit 20 has been described, but the control unit 210 can also be provided in an external circuit unit 40, for example. Furthermore, the circuit unit 20 can also be arranged outside the housing 300.

[0112] Further, in each of the above-described embodiments, an example in which the piezoelectric element 10 serves as a sensor element has been described. However, the sensor element may be constituted by an acceleration detection element, an angular velocity detection element, a temperature detection element, a light detection element, a humidity detection element, or the like. Further, a plurality of sensor elements may be provided so as to transmit detection signals corresponding to different physical quantities. For example, a piezoelectric element and a humidity detection element may be provided, and the above-described determination may be performed by combining the respective detection signals. Thereby, false determination can be further suppressed.

[0113] The control unit and method described in the present disclosure can also be implemented by a dedicated computer provided by a processor and a memory configured to execute one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure can be implemented by a dedicated computer provided by a processor constituted by one or more dedicated hardware logic circuits. Alternatively, the control unit and method described in the present disclosure can be implemented by one or more dedicated computers provided by a combination of a processor configured to execute one or more functions and a memory and a processor constituted by one or more hardware logic circuits. Further, the computer program can be stored as instructions executable by a computer in a computer-readable non-transitory tangible recording medium.

[0114] (Disclosure of the present invention)

[0115] Regarding the above-described present disclosure, for example, it can be grasped from the following viewpoints.

[0116] [First viewpoint]

[0117] A device state monitoring system, comprising:

[0118] A sensor device (S10) having a sensor element (10) that transmits a detection signal corresponding to the state of a device (30); and

[0119] A control unit (210) that performs a predetermined process based on the detection signal,

[0120] The control unit performs: a first abnormality determination that compares the detection signal with a first threshold range for grasping the state of the device, and determines that the detection signal is abnormal when the detection signal is outside the first threshold range; and a second abnormality determination that, when it is determined to be abnormal in the first abnormality determination, compares a characteristic signal indicating the characteristics of the sensor device with a second threshold range for grasping the state of the sensor device, and determines that the characteristic signal is abnormal and that an abnormality has occurred in the sensor device when the characteristic signal is outside the second threshold range.

[0121] [Second viewpoint]

[0122] The device status monitoring system according to the first aspect, characterized in that

[0123] it has a recovery unit (250, 260) provided in the sensor device,

[0124] when the control unit determines an abnormality in the first abnormality determination, before performing the second abnormality determination, it controls the recovery unit to perform a recovery operation to restore the state of the sensor device, and after the recovery operation ends, performs the second abnormality determination.

[0125] [Third aspect]

[0126] The device status monitoring system according to the first or second aspect, characterized in that

[0127] the sensor device has the sensor element and a housing (300) that houses the sensor element,

[0128] the recovery unit is a sensor element recovery unit (250) provided in the sensor element and that restores the state of the sensor element.

[0129] [Fourth aspect]

[0130] The device status monitoring system according to the first or second aspect, characterized in that

[0131] the sensor device has the sensor element and a housing (300) that houses the sensor element,

[0132] the recovery unit is a housing recovery unit (260) provided in the housing and that restores the state of the housing.

[0133] [Fifth aspect]

[0134] The device status monitoring system according to the third or fourth aspect, characterized in that

[0135] the recovery unit generates heat to heat an object.

[0136] [Sixth aspect]

[0137] The device status monitoring system according to any one of the third to fifth aspects, characterized in that

[0138] the recovery unit vibrates an object.

[0139] [Seventh aspect]

[0140] The device status monitoring system according to any one of the third to sixth aspects, characterized in that

[0141] The recovery unit applies wind pressure to the object body.

[0142] [Eighth aspect]

[0143] The equipment status monitoring system according to any one of the first to seventh aspects, characterized in that

[0144] it has a surrounding detection unit (270) that sends a status signal corresponding to the surroundings of the equipment,

[0145] When the control unit determines an abnormality in the first abnormality determination, it performs the following third abnormality determination: comparing the status signal with a third threshold range for grasping the surrounding status of the equipment, and determining that the surrounding status of the equipment is abnormal when the status signal is outside the third threshold range.

[0146] [Ninth aspect]

[0147] The equipment status monitoring system according to any one of the first to eighth aspects, characterized in that

[0148] it includes a plurality of the sensor elements that respectively send the detection signals corresponding to different physical quantities.

Claims

1. A device status monitoring system, characterized in that, Comprising: A sensor device (S10) having a sensor element (10) that transmits a detection signal corresponding to the state of a device (30); and A control unit (210) that performs a prescribed process based on the detection signal, The control unit performs: a first abnormality determination that compares the detection signal with a first threshold range for grasping the state of the device, and determines that the detection signal is abnormal when the detection signal is outside the first threshold range; And a second abnormality determination that, when it is determined to be abnormal in the first abnormality determination, compares a characteristic signal indicating the characteristics of the sensor device with a second threshold range for grasping the state of the sensor device, and determines that the characteristic signal is abnormal and that an abnormality has occurred in the sensor device when the characteristic signal is outside the second threshold range.

2. The device state monitoring system according to claim 1, characterized in that It has a recovery unit (250, 260) provided in the sensor device, When the control unit determines that it is abnormal in the first abnormality determination, before performing the second abnormality determination, it controls the recovery unit to perform a recovery operation to restore the state of the sensor device, and after the recovery operation is completed, performs the second abnormality determination.

3. The device state monitoring system according to claim 2, characterized in that The sensor device has the sensor element and a housing (300) that houses the sensor element, The recovery unit is a sensor element recovery unit (250) provided in the sensor element and that restores the state of the sensor element.

4. The device state monitoring system according to claim 2, characterized in that The sensor device has the sensor element and a housing (300) that houses the sensor element, The recovery unit is a housing recovery unit (260) provided in the housing and that restores the state of the housing.

5. The device state monitoring system according to claim 3 or 4, characterized in that The recovery unit generates heat to heat an object.

6. The device state monitoring system according to claim 3 or 4, characterized in that The recovery unit vibrates an object.

7. The device state monitoring system according to claim 3 or 4, characterized in that The recovery unit applies wind pressure to an object.

8. The device state monitoring system according to claim 1 or 2, characterized in that It has a surrounding detection unit (280) that transmits a state signal corresponding to the surroundings of the device, When the control unit determines that it is abnormal in the first abnormality determination, it performs the following third abnormality determination: compares the state signal with a third threshold range for grasping the state of the surroundings of the device, and determines that the state of the surroundings of the device is abnormal when the state signal is outside the third threshold range.

9. The device state monitoring system according to claim 1 or 2, characterized in that It includes a plurality of the sensor elements, and the plurality of sensor elements respectively transmit the detection signals corresponding to different physical quantities.

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