Self-cleaning safety system

Abstract

An apparatus includes a control circuit connected to an audio device of a security system. The safety system is used for detecting dangerous conditions. The audio device is used for warning a user of the dangerous condition. The security system includes a sensor for sensing the hazardous condition. The apparatus includes an interface for connecting the control circuit to the audio device. The control circuit is configured to determine whether to clean the housing of the sensor and to cause the audio device to vibrate or emit sound waves at an inaudible frequency based on a determination of cleaning the housing of the sensor.

Description

[0001] Priority

[0002] This application claims priority to U.S. Provisional Application No. 63 / 441,341, filed on January 26, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to safety devices such as smoke alarms, and more particularly, to a self-cleaning safety system. Background Art

[0004] The inventors of the examples of the present disclosure have discovered that lack of cleaning of safety devices, such as smoke detectors and carbon monoxide detectors, can account for a significant portion of alarm failures during emergency situations. In the case of smoke detectors, such alarm failures due to lack of cleaning have increased over the past decade. This is particularly true in the case of hardwired safety devices, which can be due to lack of maintenance due to the lack of regular battery replacement. Safety device alarm failures are a significant risk and, in the case of dusty smoke detectors, cause a significant number of avoidable injuries and deaths, as well as significant property damage, each year.

[0005] Other solutions for cleaning safety devices can be achieved by measuring changes in the baseline signal. The baseline signal can be provided, for example, during the initial calibration of the safety device and can be recorded in the safety device memory. During operation, the safety device can compare the measured signal with the baseline signal to determine whether there is any drift in the baseline signal that will indicate a dangerous condition. The baseline signal will degrade over time due to debris. Some solutions can then adjust the baseline signal by a certain coefficient to keep the baseline signal within an acceptable range for dangerous condition detection. The inventors of the examples of the present disclosure have found that this approach, while theoretically feasible, is generally ineffective in practice because the safety margin (i.e., the difference between the normal state and the alarm state) will be quickly exhausted over time. Evidence of this is that despite continuous improvements in technology and safety standards, the number of smoke alarm failures has increased significantly over time.

[0006] The inventors of the examples of the present disclosure have found that other solutions have not effectively addressed the problem of contaminant accumulation on the housing itself and lack of routine maintenance. The inventors of the examples of the present disclosure have recognized that other solutions have focused on the detection of dust and debris and applying internal compensation to the alarm sensitivity. The inventors of the examples of the present disclosure have recognized that other solutions will issue a warning or fault signal when the detected dust and debris exceeds a certain preset level. The inventors of the examples of the present disclosure have found that none of these solutions address the actual problem of accumulation itself.

[0007] Examples of the present disclosure may address one or more of these issues. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is an illustration of an apparatus for controlling operation of an example self-cleaning safety system according to an example of the present disclosure.

[0009] Figure 2 is an illustration of the operation of an apparatus for controlling operation of an example self-cleaning safety system including example operating frequencies of a sound device according to an example of the present disclosure.

[0010] Figure 3 is a more detailed illustration of an apparatus for controlling operation of an example self-cleaning safety system according to an example of the present disclosure.

[0011] Figure 4 is a more detailed illustration of the operation of an apparatus for controlling the operation of an example self-cleaning safety system according to an example of the present disclosure.

[0012] Figure 5 is a more detailed illustration of the operation of an apparatus for controlling the operation of an example self-cleaning safety system by controlling a notch filter according to an example of the present disclosure.

[0013] Figure 6 is an illustration of an example self-cleaning safety system according to an example of the present disclosure.

[0014] Figure 7 is an illustration of an example method of operating a self-cleaning safety system according to examples of the present disclosure.

[0015] Figure 8 is an illustration of another example method of operating a self-cleaning safety system according to examples of the present disclosure. DETAILED DESCRIPTION

[0016] Figure 1 1 is a diagram of a device 100 for controlling the operation of an example self-cleaning safety system 106 according to an example of the present disclosure. The device 100 may be included in the self-cleaning safety system 106 or may be separate from the self-cleaning safety system. If separate from the self-cleaning safety system 106, the device 100 may be communicatively connected to the self-cleaning safety system 106 in any suitable manner (such as by wires, communication lines, pins, buses, or wireless communication protocols). If the device 100 is included in the self-cleaning safety system 106, the self-cleaning safety system 106 may alternatively be referred to as the self-cleaning safety system 140, however, in the present disclosure, references to the self-cleaning safety system 106 are all assumed to be the self-cleaning safety system 106 may include the device 100.

[0017] The apparatus 100 may include a control circuit 102. The control circuit 102 may be configured to control the cleaning of the safety system housing 112, as well as the cleaning of any components in or attached to the safety system housing in the self-cleaning safety system 106.

[0018] The self-cleaning safety system 106 may include any suitable safety system, such as a smoke detector, a carbon monoxide (CO) detector, a radon detector, a heat detector, or any suitable combination thereof.

[0019] The self-cleaning safety system 106 may include a sensor 110. The sensor 110 may be implemented in any suitable manner and may be configured to detect any suitable physical phenomenon or condition 114. The sensor 110 may detect, for example, smoke, heat, CO, or radon, and may provide any suitable signal to a monitoring circuit (not shown) to indicate the level of the physical phenomenon or condition 114 detected by the sensor 110. In various examples, the monitoring circuit may be implemented within the control circuit 102, or separately. The monitoring circuit may be configured to take any suitable corrective action based on the signal provided from the sensor 112, such as alerting one or more users 130 through an audio device, as discussed below.

[0020] The self-cleaning safety system 100 may include an audio device 108. The audio device 108 may be configured to provide an audible sound to a user 130 based on a control signal from a monitoring circuit, the control signal being based on the level of a physical phenomenon or condition 114 detected by the sensor 110. The audio device 108 may be implemented in any suitable manner such as by a speaker, a horn, an alarm or a piezoelectric horn or device. The audio device 108 may be configured to oscillate at an audible frequency to alert one or more users 130. In addition, the audio device 108 may be configured to generate sound waves at an audible frequency to alert one or more users 130. The audio device 108 may generate a high-decibel sound as an alarm (e.g., a sound of 65 to 120 decibels (dB) when measured at a distance of 10 feet from the audio device 108), which may be heard even when the self-cleaning safety system 106 is away or the user is in a sleeping state. This high-decibel sound may sometimes be used to indicate the need for an alarm fault condition or a test. In various examples, the audio device 108 may also be used to clean the parts of the self-cleaning safety system 106.

[0021] The self-cleaning safety system 106 may include a safety system housing 112. The safety system housing 112 may be implemented in any suitable manner to house or retain the sensor 110. In addition, the safety system housing 110 may be configured to retain the self-cleaning safety system 106 or any other suitable portion of the device 100 shown in the figures of the present disclosure. The safety system housing 112 may include grilles, fins, or other openings so that the sensor 110 can sense the physical phenomenon or condition 114. The safety system housing 112 may accumulate dust, debris, particles, or any other substance that may interfere with the sensor 110's detection of the physical phenomenon or condition 114. The surface of the safety system housing 112 may be made with a non-stick coating to facilitate cleaning.

[0022] The device 100 may include an interface 104 through which the control circuit 102 may access elements of the self-cleaning safety system 106 (such as the audio device 108). The interface 104 may include any suitable mechanism through which the control circuit 102 may access elements of the self-cleaning safety system 106, such as pins, wires, buses, through holes, electrical pathways, or any other suitable mechanism for transmitting signals.

[0023] The control circuit 102 may be configured to cause the audio device 108 to clean the security system housing 112. The control circuit 102 may be configured to cause the audio device 108 to clean the security system housing 112 to dissipate dust or other particles from the physical surface of the security system housing 112. The control circuit 102 may actuate the audio device 108 to vibrate at an inaudible frequency, or emit sound waves at an inaudible frequency, in order to clean the security system housing 112.

[0024] The control circuit 102 may be configured to determine the cleaning of the safety system housing 112 based on any suitable basis. Such cleaning may be performed, for example, periodically, according to the user's requirements or based on the detection of debris. The control circuit 102 may cause the audio device 108 to vibrate or emit sound waves at an inaudible frequency based on the determination of the cleaning safety system housing 112. The operation of the audio device 108 is operated to vibrate or emit sound waves at an inaudible frequency, which may be considered as the operation of the audio device 108 in the cleaning mode. The vibration of the audio device 108 or the sound waves emitted by it may be at a frequency lower than the audible frequency range, at a frequency higher than the audible frequency range, or at a frequency higher than the audible frequency range and at a frequency lower than the audible frequency range, one after another, without requiring an order. The vibration or sound waves emitted by the audio device 108 at a frequency lower than the audible frequency range and at a frequency higher than the audible frequency range may provide a more effective cleaning than any single frequency.

[0025] The cleaning of the safety system housing 112 may be based on fixed intervals or on continuous operation, which may be adjusted based on whether the self-cleaning safety system 106 is hardwired or battery powered, for example. If the self-cleaning safety system 106 is hardwired to an external power source, the cleaning of the safety system housing 112 may be performed more frequently.

[0026] Furthermore, in some examples, the driving of the audio device 108 to perform cleaning of the security system housing 112 can be performed by measuring the voltage in the feedback from the audio device 108 in conjunction with periodic audio device fault detection. The control circuit 102 or another suitable part of the device 100 can evaluate the voltage feedback and ensure that the voltage feedback is within a normal range. An abnormal feedback range can indicate a fault, so an early warning can be conveyed to the user.

[0027] The control circuit 102 and any other monitoring circuits may be implemented in any suitable manner, such as by an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device (PLD), reprogrammable logic or hardware, analog circuitry, digital circuitry, digital logic, a microcontroller, or instructions for execution by a processor, or any suitable combination thereof.

[0028] In various examples, multiple instances of the audio device 108 can be used to generate vibrations or sound waves. In other examples, multiple instances of the audio device 108 (such as speakers) can be used, where each audio device 108 can generate different vibrations or sound wave frequencies. In some examples, the audio device 108 or other elements for cleaning the security system housing 112 can be placed in a base of the self-cleaning security system 106, such as a piece that mounts the security system housing 112 to a surface such as a wall or ceiling. In some examples, a non-stick coating (such as Teflon) can be applied to the security system housing 112 to allow vibrations to more easily remove dust and debris.

[0029] Figure 2 is an illustration of the operation of an apparatus for controlling the operation of an example self-cleaning safety system including example operating frequencies of a sound device according to an example of the present disclosure. Specifically, Figure 2 The operation of the apparatus 100 may be illustrated. The audio device 108 may be controlled by the apparatus 100 to vibrate or emit sound waves at inaudible frequencies. Figure 2 Example frequencies of such vibrations or sound waves are illustrated. For example, the audio device 108 may vibrate or emit a sound wave at an inaudible frequency that is within a frequency range below the audible frequency range, such as below 20 Hz, such as 18 Hz, as shown at (A). In another example, the audio device 108 may vibrate or emit a sound wave at an inaudible frequency that is within a frequency range above the audible frequency range, such as above 20 KHz, such as 22 KHz.

[0030] Figure 3 is a more detailed illustration of an apparatus for controlling the operation of an example self-cleaning life safety system according to an example of the present disclosure. Specifically, Figure 3 A more detailed view of the device 100 and the self-cleaning safety system 106 may be illustrated.

[0031] The apparatus 100 may control any suitable number and type of additional cleaning devices 116. The cleaning devices 116 may be operated in conjunction with the operation of the audio device 108 in the cleaning mode. The cleaning devices 116 may be implemented in any suitable manner. The cleaning devices 116 may be turned on by the control circuit 102 during the cleaning mode of the self-cleaning safety device 106 and then turned off during the normal mode of the self-cleaning safety device 106 so as not to interfere with the self-cleaning safety device 106 detecting dangerous conditions.

[0032] In one example, electrostatic precipitator 120 may constitute cleaning device 116. Electrostatic precipitator 120 may be configured to collect dust on a plate attached to the exterior of safety system housing 112 or another suitable part of self-cleaning system 106, thereby allowing for easier cleaning. Electrostatic precipitator 120 may generate an electromagnetic field around portions of safety system housing 112 to collect dust or other debris.

[0033] In one example, the pneumatic pump 118 may constitute the cleaning device 116. The pneumatic pump 118 may be configured to fill an air chamber (not shown) which may then be quickly emptied or emptied with a quick release valve (not shown) to blow out pressurized air which will remove dust and debris from the security system housing 112.

[0034] In one example, the motor-driven fan 126 may constitute the cleaning device 116 . The motor-driven fan 126 may be placed anywhere in the self-cleaning security system 106 to blow dust and debris away from the security system housing 112 .

[0035] In one example, the piezoelectric speaker 124 may constitute the audio device 108. In another example, the speaker 122 may constitute the audio device 108.

[0036] Cleaning device 116 may be activated by control circuit 102 in any suitable cleaning mode, with the same or different period as operation of audio device 108 in cleaning mode. Cleaning device 116 may be activated, for example, every tenth cleaning cycle (i.e., every tenth time audio device 108 operates in cleaning mode).

[0037] Figure 4 is a more detailed illustration of the operation of an apparatus for controlling the operation of an example self-cleaning life safety system according to an example of the present disclosure. In particular, Figure 4The operation of the control circuit 102 on the audio device 108 is illustrated. In addition, the operation on the audio device 108 may also be performed on an additional cleaning device 116 (not shown).

[0038] At (1), the control circuit 102 may determine to enter a test mode of the audio device 108. The test mode may include any suitable cleaning mode as described above. That is, the test mode and the cleaning mode may be performed together.

[0039] At (2), the control circuit 102 may cause the audio device 108 to vibrate or emit sound waves at an inaudible frequency.

[0040] At (3), the control circuit 102 may receive or measure a voltage fed back from the audio device 108 .

[0041] At (4), the control circuit 102 may determine whether the feedback voltage from the audio device 108 is within an acceptable range.

[0042] At (5), the control circuit 102 may determine a possible failure of the audio device 108 based on the determination in (4) and issue an alert.

[0043] Figure 5 is a more detailed illustration of the operation of a device for controlling the operation of an example self-cleaning safety system to vibrate or emit sound waves at an inaudible frequency by controlling a notch filter according to an example of the present disclosure.

[0044] The control circuit 102 may utilize one or more driver circuits to drive the audio device 108 or the cleaning device 116. Such driver circuits may be implemented in any suitable manner, such as by an ASIC, an FPGA, a PLD, reprogrammable logic or hardware, an analog circuit, a digital circuit, digital logic, a microcontroller, instructions for execution by a processor, or any suitable combination thereof. Such driver circuits may be configured to perform any suitable signal conditioning on control signals issued by the control circuit 102 so that such control signals may affect control of the audio device 108 or the cleaning device 116. Such driver circuits may be implemented in any suitable location, such as within the apparatus 100 or the self-cleaning safety system 106. A single driver circuit may be used for both the audio device 108 and the cleaning device 116, or multiple driver circuits may be used as described above. Figure 5 As shown in the example of FIG. 5 , separate driver circuits 502 , 504 may be used for the audio device 108 and the cleaning device 116 , respectively.

[0045] The notch filter 506 may be placed on any control line between the control circuit 102 and the audio device 108 and the cleaning device 116. For example, the notch filter 506 may be placed between the control circuit 102 and the driver circuits 502, 504. The notch filter 506 may be implemented in any suitable manner, such as by an ASIC, FPGA, PLD, reprogrammable logic or hardware, analog circuitry, digital circuitry, digital logic, a microcontroller, instructions for execution by a processor, or any suitable combination thereof.

[0046] The notch filter 506 may be activated by the control circuit 102 when the self-cleaning safety system 106 is in the cleaning mode, and the notch filter may be deactivated by the control circuit 102 when the self-cleaning safety system 106 is in the normal mode. The notch filter 506 may allow the audio device 108 or the cleaning device 116 to operate only at the frequencies of interest (i.e., one or more inaudible frequencies). For example, a piezoelectric speaker may resonate at an otherwise audible peak that wastes energy and produces audible sound.

[0047] Figure 6 is a diagram of an example self-cleaning safety device 600 according to an example of the present disclosure. The device 600 may implement Figures 1 to 5 The apparatus 600 may include a sensor 610 for detecting a dangerous condition 614. The apparatus 600 may include an audio device 608 for alerting a user 630 of the dangerous condition 614. The apparatus 600 may include a safety system housing 612 for housing the sensor 610. The apparatus 600 may include a control circuit 602 to determine whether the apparatus 600 is operated in a cleaning mode or in a normal mode. The control circuit 602 may be configured to determine whether the sensor 610 has detected the dangerous condition 614 based on a determination that the apparatus 600 is operated in the normal mode. The control circuit 602 may be configured to cause the audio device 608 to alert the user 630 of the dangerous condition 614 by driving the audio device 608 to vibrate or emit sound waves at an audible frequency based on a determination that the sensor 610 has detected the dangerous condition 614. The control circuit 602 may be configured to cause the cleaning of the safety system housing 612 by causing the audio device 608 to vibrate or emit sound waves at an inaudible frequency based on a determination that the apparatus 600 is operated in the cleaning mode.

[0048] Control circuit 602 may be implemented as described above with respect to control circuit 102. Security system housing 612 may be implemented as described above with respect to security system housing 112. Sensor 610 may be implemented as described above with respect to sensor 110. Audio device 608 may be implemented as described above with respect to audio device 108. Condition 614 may be as described above with respect to condition 114. User 630 may be any suitable user of apparatus 600. Apparatus 600 may be implemented as described above with respect to system 106.

[0049] In addition, if Figure 2 As shown in relation to the control circuit 102, the control circuit 602 may be configured to cause the audio device 608 to vibrate or emit sound waves at an inaudible frequency based on a determination that the apparatus 600 is operating in a cleaning mode by causing the audio device 608 to vibrate or emit sound waves at a frequency above the audible frequency range, at a frequency below the audible frequency range, or both.

[0050] Figure 7 is a diagram of an example method 700 of operating a self-cleaning safety system according to an example of the present disclosure. The method 700 may be performed by any suitable elements such as Figures 1 to 6 The method 700 may be performed by the components of the control circuit shown in FIG. Figure 7 More or fewer steps may be performed as shown, and the steps of method 900 may optionally be omitted, repeated, performed in a different order, performed in parallel, or performed recursively.

[0051] At 705, it can be determined whether the device is operated in a cleaning mode or a normal mode. If the device is operated in a normal mode, the method 700 can proceed to 710. Otherwise, the method 700 can proceed to 720.

[0052] At 710, based on the determination that the device is operating in the normal mode, it may be determined whether a sensor of the device has detected a dangerous condition. If a dangerous condition has been detected, the method 700 may proceed to 715. Otherwise, the method 700 may return to 705.

[0053] At 715, based on the determination that the sensor has detected a dangerous condition, an audio device of the apparatus may be caused to alert a user of the dangerous condition. The alert may be audible. The alert may be generated by an audio device such as a piezoelectric horn or speaker vibrating or emitting sound waves at one or more audible frequencies. Method 700 may return to 705.

[0054] At 720 , based on a determination to operate the device in a cleaning mode, cleaning of the housing of the sensor may be induced by causing the audio device to vibrate or emit sound waves at an inaudible frequency. Method 700 may return to 705 .

[0055] Figure 8 8 is a diagram of an example method 800 of operating a self-cleaning safety system according to an example of the present disclosure. The method 800 may be performed by any suitable elements such as Figures 1 to 6 The method 800 may be performed by the components of the control circuit shown in FIG. Figure 8 More or fewer steps may be performed as shown, and the steps of method 800 may optionally be omitted, repeated, performed in a different order, performed in parallel, or performed recursively.

[0056] At 805, it can be determined whether the device is operated in a cleaning mode or a normal mode. If the device is operated in a normal mode, the method 800 can proceed to 810. Otherwise, the method 800 can proceed to 820.

[0057] At 810, based on a determination that the device is operating in a normal mode, a notch filter for filtering out frequencies other than inaudible frequencies may be turned off. A determination may be made as to whether a sensor of the device has detected a dangerous condition. If a dangerous condition has been detected, method 800 may proceed to 815. Otherwise, method 800 may return to 805.

[0058] At 815, based on the determination that the sensor has detected a dangerous condition, an audio device of the apparatus may be caused to alert a user of the dangerous condition. The alert may be audible. The alert may be generated by an audio device such as a piezoelectric horn or speaker vibrating or emitting sound waves at one or more audible frequencies. Method 800 may return to 805.

[0059] At 820, based on the determination that the device is operating in the cleaning mode, a notch filter may be turned on to filter out frequencies other than inaudible frequencies. Cleaning of the housing of the sensor may be caused by causing an audio device to vibrate or emit sound waves at inaudible frequencies. The audio device may be caused to vibrate or emit sound waves at a frequency above the audible frequency range, below the audible frequency range, or above and below the audible frequency range. The audio device may be the same audio device used to alert the user in 815. For example, the audio device may be a piezoelectric horn or a speaker.

[0060] At 825, it may be determined whether additional cleaning equipment will be used to clean the housing. If so, method 800 may proceed to 830. Otherwise, method 800 may proceed to 835.

[0061] At 830 , based on a determination that the device is operating in a cleaning mode and using an additional cleaning device, the additional cleaning device may be caused to clean the sensor. The additional cleaning device may include, for example, an electrostatic precipitator, a pneumatic pump, or a fan. Method 800 may proceed to 835 .

[0062] At 835, it may be determined whether the test mode is entered in conjunction with the cleaning mode. If so, the method 800 may proceed to 840. Otherwise, the method 800 may return to 805.

[0063] At 840, the audio device may be caused to vibrate or emit sound waves at inaudible frequencies. This may be the same or different from the option performed in 820, i.e., a notch filter may be turned on to filter out frequencies other than inaudible frequencies.

[0064] Feedback from the audio device may be measured at 845. Feedback may be generated by causing the audio device to vibrate or emit sound waves at inaudible frequencies.

[0065] At 850, it may be determined whether the voltage is within an acceptable range. If so, the method 800 may return to 805. Otherwise, the method 800 may proceed to 855.

[0066] At 855 , based on a determination that the voltage is not within an acceptable range, a possible fault in the audio device may be determined and an alert may be issued. Method 800 may return to 805 .

[0067] Examples of the present disclosure may include an apparatus.

[0068] The device may include control circuitry. The control circuitry may be implemented in any suitable manner, such as by an application specific integrated circuit, a field programmable gate array, a programmable logic device, reprogrammable logic or hardware, analog circuitry, digital circuitry, digital logic, a microcontroller, or instructions for execution by a processor, or any suitable combination thereof.

[0069] The control circuit may be configured to connect to an audio device of a security system.The security system may include any suitable security system, such as a smoke detector, a carbon monoxide (CO) detector, a radon detector, a heat detector, or any suitable combination thereof.

[0070] The audio device can be implemented in any suitable manner such as by a speaker, a horn, an alarm or a piezoelectric horn or device. The audio device can be configured to oscillate at an audible frequency to alert one or more users. In addition, the audio device can be configured to generate sound waves at an audible frequency to alert one or more users.

[0071] The safety system may include a sensor for sensing a hazardous condition. The sensor may be implemented in any suitable manner and may be configured to detect any suitable physical phenomenon or condition, such as smoke, heat, CO, or radon, and may provide any suitable signal to the monitoring circuit to indicate the level of the physical phenomenon or condition detected by the sensor.

[0072] The apparatus may include an interface for connecting the control circuit to the audio device. The interface may include any suitable mechanism by which the control circuit can access elements of the security system, such as pins, wires, buses, through holes, electrical pathways, or any other suitable mechanism for transmitting signals.

[0073] The control circuit may be configured to determine whether the housing of the sensor is clean, and based on a determination that the housing of the sensor is clean, cause the audio device to vibrate or emit sound waves at an inaudible frequency.

[0074] In conjunction with any of the above examples, the control circuit can be configured to cause the audio device to vibrate or emit sound waves at an inaudible frequency based on a determination to clean the housing of the sensor by causing the audio device to vibrate or emit sound waves at a frequency above the audible frequency range.

[0075] In conjunction with any of the above examples, the control circuit can be configured to cause the audio device to vibrate or emit sound waves at an inaudible frequency based on a determination to clean the housing of the sensor by causing the audio device to vibrate or emit sound waves at a frequency below the audible frequency range.

[0076] In combination with any of the above examples, the control circuit can be configured to cause the audio device to vibrate or emit sound waves at an inaudible frequency based on a determination of cleaning the housing of the sensor by causing the audio device to vibrate or emit sound waves at a first frequency above the audible frequency range and at a second frequency below the audible frequency range.

[0077] In conjunction with any of the above examples, the control circuit can be configured to cause an additional cleaning device to clean the housing of the sensor based on a determination to clean the housing of the sensor.

[0078] In conjunction with any of the above examples, the additional cleaning device may be an electrostatic precipitator for cleaning the housing of the sensor.

[0079] In conjunction with any of the above examples, the additional cleaning device may be a pneumatic pump for cleaning the housing of the sensor.

[0080] In conjunction with any of the above examples, the additional cleaning device may be a fan for cleaning the housing of the sensor.

[0081] In conjunction with any of the above examples, the audio device may be a speaker or a loudspeaker.

[0082] In combination with any of the above examples, the control circuit can be configured to cause the audio device to periodically vibrate or emit sound waves at an inaudible frequency in a test mode; measure a voltage of feedback from the audio device, which is generated by causing the audio device to vibrate or emit sound waves at an inaudible frequency; determine whether the voltage is within an acceptable range; and based on the determination that the voltage is not within an acceptable range, determine a possible fault in the audio device and issue an alarm.

[0083] In conjunction with any of the above examples, the control circuit can be configured to control the notch filter to filter out frequencies other than inaudible frequencies, including turning off the notch filter when the audio device is alerting the user about a dangerous condition, and turning on the notch filter when the audio device is cleaning the housing.

[0084] Examples of the present disclosure may include a device. The device may include any of the devices in the above examples, including the control circuit therein. The device may include a sensor, an audio device, and a housing.

[0085] Examples of the present disclosure may include a method performed by any of the above examples.

[0086] Although exemplary embodiments have been described above, the present disclosure may have other variations and embodiments without departing from the spirit and scope of these embodiments.

Claims

1. A device, comprising: a control circuit for connecting to an audio device of a security system, the security system for detecting a dangerous condition, the audio device for alerting a user to the dangerous condition, the security system including a sensor for sensing the dangerous condition; and an interface for connecting the control circuit to the audio device; The control circuit is used to: determining whether to clean the housing of the sensor; and The audio device is caused to vibrate or emit sound waves at an inaudible frequency based on a determination that the housing of the sensor is clean.

2. The apparatus of claim 1 , wherein the control circuit is configured to cause the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a frequency above an audible frequency range based on the determination to clean the housing of the sensor.

3. An apparatus according to any one of claims 1 to 2, wherein the control circuit is used to cause the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a frequency below the audible frequency range based on the determination to clean the housing of the sensor.

4. An apparatus according to any one of claims 1 to 3, wherein the control circuit is used to cause the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a first frequency above the audible frequency range and at a second frequency below the audible frequency range based on the determination to clean the housing of the sensor.

5. The apparatus of any one of claims 1 to 4, wherein the control circuit is configured to cause an additional cleaning device to clean the housing of the sensor based on the determination to clean the housing of the sensor.

6. The apparatus of claim 5, wherein the additional cleaning device is an electrostatic precipitator for cleaning the housing of the sensor.

7. The apparatus of claim 5, wherein the additional cleaning device is a pneumatic pump for cleaning the housing of the sensor.

8. The apparatus of claim 5, wherein the additional cleaning device is a fan for cleaning the housing of the sensor.

9. The apparatus according to any one of claims 1 to 8, wherein the audio device is a speaker or a loudspeaker.

10. The apparatus according to any one of claims 1 to 9, wherein the control circuit is configured to, in a test mode: causing the audio device to vibrate or emit sound waves at the inaudible frequency periodically; measuring a voltage of feedback from the audio device, the feedback being generated by causing the audio device to vibrate or emit sound waves at the inaudible frequency; determining whether the voltage is within an acceptable range; as well as Based on a determination that the voltage is not within the acceptable range, a possible fault in the audio device is determined and an alert is issued.

11. An apparatus according to any one of claims 1 to 10, wherein the control circuit is used to control a notch filter to filter out frequencies other than the inaudible frequencies, including turning off the notch filter when the audio device is issuing the warning to the user about the dangerous condition, and turning on the notch filter when the audio device is allowed to clean the housing.

12. A method comprising: determining whether to operate the device in a cleaning mode or a normal mode; determining, based on a determination to operate the device in the normal mode, whether a sensor of the device has detected a hazardous condition; causing an audio device of the apparatus to alert a user of the dangerous condition based on a determination that the sensor of the apparatus has detected the dangerous condition; Based on a determination to operate the apparatus in the cleaning mode, a housing of the sensor is cleaned by causing the audio device to vibrate or emit sound waves at an inaudible frequency.

13. The method of claim 12, comprising causing the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a frequency above an audible frequency range based on the determination to operate the apparatus in the cleaning mode.

14. A method according to any one of claims 12 to 13, comprising causing the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a frequency below the audible frequency range based on the determination to operate the device in the cleaning mode.

15. A method according to any one of claims 12 to 14, comprising causing the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a first frequency above the audible frequency range and at a second frequency below the audible frequency range based on the determination to operate the device in the cleaning mode.

16. A method according to any one of claims 12 to 15, comprising causing an additional cleaning device to clean the sensor based on the determination to operate the apparatus in the cleaning mode.

17. The method of claim 16, wherein the additional cleaning device is an electrostatic precipitator for cleaning the housing of the sensor.

18. The method of claim 16, wherein the additional cleaning device is a pneumatic pump for cleaning the housing of the sensor.

19. The method of claim 16, wherein the additional cleaning device is a fan for cleaning the housing of the sensor.

20. The method of claim 12, wherein the audio device is a speaker or a loudspeaker.

21. A method according to any one of claims 12 to 20, comprising, in a test mode: causing the audio device to vibrate or emit sound waves at the inaudible frequency periodically; measuring a voltage of feedback from the audio device, the feedback being generated by causing the audio device to vibrate or emit sound waves at the inaudible frequency; determining whether the voltage is within an acceptable range; as well as Based on a determination that the voltage is not within the acceptable range, a possible fault in the audio device is determined and an alert is issued.

22. A method according to any one of claims 12 to 21, comprising using a notch filter to filter out frequencies other than the inaudible frequencies, comprising switching the notch filter off in the normal mode and switching the notch filter on in the cleaning mode.

23. A device, comprising: A sensor for detecting a dangerous condition; an audio device for alerting a user of the apparatus to the dangerous condition; a housing, the housing including the sensor; and A control circuit, the control circuit being used for: determining whether to operate the device in a cleaning mode or a normal mode; determining whether the sensor has detected the hazardous condition based on a determination to operate the device in the normal mode; as well as Based on a determination that the sensor of the apparatus has detected the hazardous condition, causing the audio device to alert a user of the hazardous condition by causing the audio device to vibrate or emit sound waves at an audible frequency; and Based on a determination to operate the apparatus in the cleaning mode, the housing is cleaned by causing the audio device to vibrate or emit sound waves at an inaudible frequency.

24. The apparatus of claim 23, wherein the control circuit is to cause the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a frequency above the audible frequency range based on the determination to operate the apparatus in the cleaning mode.

25. An apparatus according to any one of claims 23 to 24, wherein the control circuit is used to cause the audio device to vibrate or emit sound waves at the inaudible frequency by causing the audio device to vibrate or emit sound waves at a frequency below the audible frequency range based on the determination to operate the apparatus in the cleaning mode.

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