Sensing device using MEMS technology and prognostic health monitoring
A sensor component that may be used in conjunction with a filter module may include a plurality of sensor packages. The latter, in turn, may incorporate one or more micro-electromechanical systems (MEMS) sensors to measure various characteristics of fluid flow and filtration. A single sensor component may be adapted to measure the pressure, temperature, flow rate, differential pressure, conductivity, viscosity, pH level, etc. of the fluid at an upstream and a downstream location. Sensor measurements may be obtained continuously in order to monitor and indicate fluid conditions, including the use of a warning mechanism to indicate an out-of-range condition when the measurements fall outside of pre-set limits. Depending on the application and the fluid being filtered, data, including measurement data, may be transmitted through electrical connections or wirelessly. In wireless configurations, a sleep-mode may be included to maximize the life of local power supplies.
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This is a continuation of application Ser. No. 10/281,835, filed Oct. 28, 2002, now U.S. Pat. No. ______, and is related to application Ser. No. 10/818,248, filed Apr. 5, 2004, now U.S. Pat. No. ______, which is a continuation of Ser. No. 10/259,905, filed Sep. 27, 2002, now U.S. Pat. No. 6,736,980, which is a division of Ser. No. 09/721,499, filed Nov. 22, 2000, now U.S. Pat. No. 6,471,853; to application Ser. No. 10/903,727, filed Jul. 30, 2004, which is a continuation of Ser. No. 10/281,692, filed Oct. 28, 2002, now U.S. Pat. No. 6,823,718; and to application Ser. No. 10/281,834, filed Oct. 28, 2002, now pending.
FIELD OF INVENTIONThe present invention is directed to filtration systems incorporating micro-electromechanical systems (MEMS) to provide flow and filtration characteristic data.
BACKGROUNDFilter modules have been used in a variety of applications and fluidic environments. When in service, it is often desirable to sense and measure various fluid flow and filter performance characteristics in order to determine whether a filter element within the filter module is performing within application specifications, and whether a filter element must be replaced or reconditioned before continuing operation.
In typical filter modules, a filter element is encased within a filter body, or casing (e.g., a filter bowl), and between inlet and outlet end caps. A filter manifold(s) may be attached to the filter body to feed unfiltered medium to the upstream side of the filter element (e.g., where the filter element is cylindrical, the outside of the filter element). As the medium passes to the downstream side of the filter element through the membrane material, contaminants are removed from the medium. Filtered medium is then collected from the downstream side of the filter element (e.g., where the filter element is cylindrical, the inside of the filter element).
During the filter element's service life, an increasing amount of removed contaminant will collect on one side of the filter element in a phenomenon known as fouling. Fouling causes the pressure difference between the upstream and downstream sides of the filter element to increase, and thereby lowers the filtration efficiency of the filter element. If the differential pressure exceeds a certain value that is dependent upon the filter element material and design, the filter element may be damaged. Additionally, at high differential pressures, particle breakthrough (i.e., contaminant particles passing through the pores in the filter element) may occur.
In prior modules, the filter head may have contained conventional pressure transducers, magnetic type differential pressure sensors, virtual pressure switches, and temperature detectors to measure characteristics of fluid flow and filter performance. These components are used to sense the differential pressure across the filter element to determine whether the filter element is sufficiently clogged with contaminant removed from the fluid flow to require replacement. These pressure sensors are generally binary in nature, i.e., they either indicate that the filter element needs to be replaced (e.g., by causing a part to pop up out of the exterior of the filter head) or that it is still useable.
Typically, traditional differential pressure indicators (e.g., spring and piston designs) contain a multiplicity of discrete, macro-scale, mechanical parts and/or components, which makes them more prone to failure. As an example, a thermal lockout mechanism is typically used to prevent false indications during cold-start conditions. In existing designs, the thermal lockout mechanism uses the thermal expansion qualities of BI-metal strips to keep the differential pressure indicator from actuating until a pre-set temperature is reached. However, false indications are received when mechanical failures occur within the lockout mechanism.
The use of the pressure-sensing components used in traditional filter modules is also often a significant design constraint in weight- and size-sensitive applications, e.g., aircraft filtration systems. Moreover, traditional filter modules offer no real-time means for predicting when a filter element will need to be replaced. In addition, traditional filter modules disturb or alter fluid flow by requiring that sensing components be inserted into the stream of flow, creating turbulence. Also, prior sensors are designed to indicate an out-of-range condition when the value of a measured property falls outside of pre-set limits. As such, continuous measurement and real-time monitoring and indication may not be available with such designs.
Moreover, traditionally, separate devices have typically been used to measure different properties (e.g., temperature and pressure), thus increasing the size and cost of the overall system. Similarly, at present, filter or fluid power manifolds that have separate upstream circuits but share a common downstream passage require the use of separate devices to measure, e.g., differential pressure, across each filter element (or any device or component that provides a measurable pressure drop). This also holds true for filter or fluid power manifolds that have separate downstream circuits, but share a common upstream passage. As before, the use of separate individual devices is generally disadvantageous as it leads to increased cost, weight, design envelope size, and reduced reliability.
In recent years, attempts have been made to overcome the above-mentioned shortcomings by using Micro-Electro-Mechanical Systems (MEMS) devices in conjunction with filter modules. MEMS devices comprise semiconductor chips which include microfabricated mechanical systems on the chip. More generally, MEMS are directed to the integration of mechanical elements, sensors, actuators, and electronics on a common substrate through the utilization of microfabrication technology. While the electronics are fabricated using integrated circuit (IC) process sequences, the micromechanical components are fabricated using compatible micromachining processes that selectively etch away parts of a silicon wafer, e.g., or add new structural layers (e.g., by deposition), to form the mechanical and electromechanical devices. In this way, MEMS represents a complete systems-on-a-chip, free of discrete, macro-scale, moving mechanical parts. In short, in MEMS devices, the microelectronic integrated circuits provide the decision-making capability which, when combined with MEMS sensors, actuators, etc., allow microsystems to sense, provide feedback to/from, and control the environment.
Thus, commonly-assigned U.S. application Ser. No. 09/721,499, filed Nov. 22, 2000, now U.S. Pat. No. 6,471,853, is directed to a filter module that incorporates MEMS sensors to measure various characteristics of fluid flow and filtration, including the temperature, flow rate, pressure, etc. of the fluid. One or more MEMS sensors may be incorporated into a sensor package which, in turn, is included in a sensor component. The latter, which typically may include a processor, conductor pins, etc. for data communication, is coupled to a sensor port of a manifold in such a way as to allow contact between the fluid and at least one surface of the sensor(s).
As shown in
The filter element 2 may have an end cap 9 attached to one end (the dead end). In general, the shape and location of the inlet fluid flow cavity 6 and the outlet fluid flow cavity 7 may depend upon a number of factors, including the desired flow characteristics of the unfiltered or filtered fluid, the size and shape of the filter element 2 and filter body 1, the fluid being filtered, and the like. Each sensor component 5 includes a sensor package 10 which contains one or more MEMS sensors. As shown in
In order to measure the differential pressure between two locations of fluid flow (e.g., across a filter element 2) using MEMS sensor components of the type described above, at least two such sensor components must be used. More specifically, a first MEMS sensor component 5 having at least one pressure sensor is deployed at an upstream location, e.g., within a port 4 in an inlet cavity 6, and a second MEMS sensor component 5 having at least one pressure sensor is deployed at a downstream location, e.g., within a port 4 in an outlet cavity 7. Respective pressure readings from the first and second sensor components are communicated to a processor or similar device through electrical conductors, and a differential pressure across the membrane of the filter element 2 is calculated based on the difference between the first and second sensor component readings.
MEMS sensor components of the type described above have thus improved upon conventional modules and sensors by eliminating macro-scale mechanical parts, addressing weight and size concerns, allowing real-time monitoring, and providing a sensor package that can be placed flush with the stream of flow, thus avoiding interference with fluid flow. Nevertheless, in light of the high cost of retrofittable sensors (e.g., differential pressure sensors) and the difficulties associated with wiring such sensors to a “communications bus”, there is a need for low-cost, lower-weight, reliable, non-mechanical sensing devices that may be retrofittable, capable of integrating one or more differential pressure sensors, and capable of wirelessly communicating sensing- and measurement-related data.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention are directed to sensor components in which various MEMS sensors for measuring pressure, differential pressure, flow rate, temperature, pH level, viscosity, and/or moisture content of the fluid flow may be used. Multiple MEMS sensors may be arranged on a single chip to form a sensor package, and multiple sensor packages may be included in a single, unitary sensor component. The MEMS sensors may output real-time measurements or related data, thus allowing real time continuous monitoring of the fluid system. The measurements or data may be interpreted to predict when failure of the filter element will occur or to determine whether replacement of the filter element is necessary. In particular embodiments, MEMS sensor data may be used to detect the occurrence of undesirable events such as particle breakthrough or cavitation.
In addition to allowing real time continuous monitoring (as opposed to merely providing an indication at pre-set values), the present invention improves reliability by reducing the number of macro-scale mechanical components and/or moving parts that are typically used in traditional systems, as well as by allowing redundancy of sensor packages and/or of sensors within a given sensor package. Moreover, by including multiple MEMS sensors on a sensor package, the present invention eliminates the need for separate devices to measure temperature, pressure, differential pressure, etc. This, in turn, reduces costs, as well as system weight and envelope size.
In some embodiments, a single sensor component may contain multiple pressure sensors which are configured in such a way as to allow determination of a differential pressure without the need to include an additional sensor component. Thus, the inclusion of multiple sensor packages in a single sensor component allows installation, or retro-fitting, in applications where only one port is available and traditional devices and methods would require two separate sensor ports and assemblies (e.g., measuring differential pressure with a single sensor component placed into a single port, as opposed to placing two separate sensor assemblies into two separate ports).
Embodiments of the present invention are also directed to single-body sensor components (e.g., single-body differential pressure devices) that may be used in systems having multiple separate upstream circuits that share a common downstream passage or, vice versa, where multiple separate downstream circuits share a common upstream passage. In one embodiment, the present invention also provides a MEMS sensor component having a wireless data-communication capability.
In a preferred embodiment, at least one of the sensor packages (e.g., the first sensor package 522) is exposed directly to the upstream fluid, i.e., the fluid that is transmitted to the inlet side of the filter element. Thus, as shown in
A second sensor package, however, might not be flush with the stream of fluid flow. Rather, as depicted in
In embodiments of the present invention, data collected using the multiplicity of sensors and/or sensor packages may be processed and/or transmitted through the use of electrical conductors and data-processing devices. For example, the embodiment shown in
Advantageously, using the data collection/transmission/processing capabilities described herein, embodiments of the present invention allow for measurement of differential pressure and similar parameters using a single MEMS sensor component by including multiple sensor packages within the same sensor component. This is especially desirable in applications (e.g., retrofitting/updating older systems) where only one sensor-component port, rather than two, is available for measuring differential pressure and other such parameters. In addition, in contrast to existing designs, where an indication is provided only when pre-set parameter values have been reached, embodiments of the present invention allow continuous real-time monitoring of the fluid system.
Moreover, embodiments of the present invention achieve improved reliability by allowing the use of redundant sensor packages, as well as redundant sensors in each sensor package. Also, the sensors may be temperature compensated to ensure accuracy over the entire mission range. In addition, given their relatively small mass, the MEMS sensor packages are inherently tolerant of extreme vibrational environments.
In an alternative embodiment, shown in
The embodiment shown in
As shown in
Taking advantage of the principles discussed herein, however, embodiments of the present invention allow for the use of fewer sensing devices. For example, only three sensor components of the type discussed in connection with
When either a common upstream passage or a common downstream passage exists, however, an alternative embodiment of the present invention enables calculation of all of the differential pressures using a single MEMS sensor component (i.e., a single-body differential pressure sensing device). Thus, with reference to the schematic of
It is noted that each of the sensor packages mentioned above may include additional sensors, e.g., one or more MEMS temperature sensors in addition to the at least one MEMS pressure sensor. Also, as shown by way of example in
As shown in
Data collected using the multiplicity of sensors and/or sensor packages may be processed and/or transmitted through the use of electrical conductors and data-processing devices. To this end, sensor component 700 includes an electrical housing 715 which may include electrical conductors, one or more processors, and/or conductive pins (within an electrical connector 710) which may be configured to allow transmission of data to/from a data processing device.
In addition, the sensor component 700 may include a visual warning light, an audible alarm, or other warning mechanism that is configured to indicate an out-of-range condition of the fluid for each of the hydraulic components being monitored. Moreover, similar to flange 680 shown in
As shown in
The sensor component 860 may be retained in the port 868 using one or more retaining braces 862, 864, 866, which may be overlapped. In one embodiment, each of the retaining braces 862, 864, 866 includes transverse apertures 863, 865, 867, respectively, which come into alignment with end cap apertures 869. The end cap 9 and the brace(s) are then held together by passing connection means 861, such as pins, or snap members, through the end cap apertures 869 and the transverse apertures 863 (865, 867).
As has been discussed in connection with embodiments described previously, the sensor component 860 may also include hardware, including one or more processors, electronics, etc. for processing measurement data prior to transmission. In addition, the sensor component 860 may include a power supply 890. In a preferred embodiment, the power supply 890 includes a battery, which may be rechargeable, and which provides the sensor component 860 with stand-alone, wireless, functioning capabilities.
In practice, the filter element 2 having a sensor component 860 in an end cap 9 thereof is housed by the casing 850 having a signal receiver 852 in a bottom end 851 thereof. The sensor component includes sensor packages that are in communication with the unfiltered and filtered fluids. Thus, as fluid flows through the filter, the sensor component 860 determines a differential pressure across the filter element 2. In one embodiment, the measurement data is then transmitted, wirelessly, to the signal receiver 852, when a predetermined differential pressure is reached. In another embodiment, data is wirelessly transmitted in predetermined intervals, or continuously in real time.
Depending on the type and properties of the fluid being filtered, the data transmission between the sensor component 860 and the signal receiver 852 may be achieved through RF signals, ultra-sonically, or through other means of wireless communication. Once received by the signal receiver 852, the data may be either processed locally or transmitted to a central computer or data processing device, as discussed with respect to the embodiments of
In one embodiment, the invention may include a sleep-mode feature, wherein the MEMS sensors of the sensor component 860, as well as the signal receiver 852, are configured to remain in an unactuated state in the absence of fluid flow. Once fluid flow has been initiated, the sensors become actuated, so that measurement data can now be taken. In addition, the signal receiver 852 will become actuated upon receipt of measurement data. When in the sleep-mode, the sensor component's power supply is configured to utilize minute amounts of current, e.g., on the order of micro-amperes. As such, once activated, the power supply will sustain the sensor component as a self-powered unit for upwards of 6000 hours. Similarly, once activated, the signal receiver 852 will remain self-sustaining for upwards of 3000 hours. As noted before, the sensor component 860 and the signal receiver 852 may be removed or replaced when the filter element 2 is replaced with a new filter element.
While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.
The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description. All changes that come within the meaning, and range of equivalency, of the claims are intended to be embraced therein.
Claims
1. A filtration monitoring system comprising:
- a filtration module including a filter element, said filter element receiving a fluid in an unfiltered state at an inlet side upstream of the filter element and producing said fluid in a filtered state at an outlet side downstream of the filter element;
- a single-body sensor component disposed proximate one of said inlet side and said outlet side, said sensor component comprising: (a) a plurality of sensor packages, each said sensor package including a micro-electromechanical system (MEMS) sensor and being configured to measure at least one parameter selected from the group consisting of pressure, temperature, and flow rate; (b) a plurality of sensor-package receptacles, wherein each one of said receptacles is configured to selectively receive a respective one of said sensor packages; and (c) a casing housing said sensor packages and said sensor-package receptacles; and
- a data-processing device configured to receive measurement data collected by each of said sensor packages.
2. The filtration monitoring system of claim 1, wherein at least one of said plurality of sensor packages is adapted to be in communication with said unfiltered fluid upstream of the filter element and at least one of said plurality of sensor packages is adapted to be in communication with said filtered fluid downstream of the filter element.
3. The filtration monitoring system of claim 1, wherein at least one of said plurality of sensor packages is configured to measure at least one parameter selected from the group consisting of a conductivity, a pH level, and a viscosity of the unfiltered fluid.
4. The filtration monitoring system of claim 1, wherein at least one of said plurality of sensor packages is in direct contact with said unfiltered fluid.
5. The filtration monitoring system of claim 1, wherein each of the plurality of sensor packages includes at least one of a temperature sensor, a flow rate sensor, and a pressure sensor.
6. The filtration monitoring system of claim 5, wherein at least one of the sensor packages includes redundant sensors.
7. The filtration monitoring system of claim 6, wherein at least one of the sensor packages includes one or more sensors for measuring one or more of a conductivity, a pH level, and a viscosity of said fluid.
8. The filtration monitoring system of claim 5, wherein said single-body sensor component includes a redundant sensor package.
9. The filtration monitoring system of claim 1, wherein each of said plurality of sensor packages includes a plurality of MEMS sensors.
10. The filtration monitoring system of claim 1, wherein said single-body sensor component further includes conductive pins configured to mate with the data-processing device.
11. The filtration monitoring system of claim 1, wherein at least one of said plurality of sensor packages is configured to measure a pressure of the unfiltered fluid, at least one of said plurality of sensor packages is configured to measure a pressure of the filtered fluid, and said data-processing device is configured to calculate a differential pressure based on said pressure measurements.
12. The filtration monitoring system of claim 1, wherein the single-body sensor component further includes at least one of a visual warning light and an audible alarm configured to indicate an out-of-range condition of said fluid.
13. The filtration monitoring system of claim 12, wherein said condition is determined based on measurement of one or more of said fluid's pressure, temperature, flow rate, and differential pressure.
14. The filtration monitoring system of claim 12, wherein said visual warning light is disposed proximate a longitudinal end of said sensor component.
15. The filtration monitoring system of claim 12, wherein the casing housing the sensor packages and sensor-package receptacles defines circumferential holes through the periphery thereof, said visual warning light being disposed within said casing so as to provide a visual out-of-range indication through said holes.
16. The filtration monitoring system of claim 1, further including a filter manifold, wherein the single-body sensor component includes a flange that is disposed around the periphery of said casing so as to lie in a plane perpendicular to the longitudinal axis of the sensor component, said flange being configured to be coupled to said manifold by connecting means.
17. The filtration monitoring system of claim 1, wherein said single-body sensor component is configured to measure differential pressure.
18. The filtration monitoring system of claim 1, said single-body sensor component further including a processor.
19. The filtration monitoring system of claim 18, wherein each said sensor package is configured to take a measurement upon receiving a signal from said processor.
20. The filtration monitoring system of claim 1, wherein at least one of said plurality of sensor packages is in communication with the filtered fluid through an aperture defined in the periphery of said casing.
21. The filtration monitoring system of claim 20, wherein at least one of said plurality of sensor packages is in direct contact with the unfiltered fluid.
22. The filtration monitoring system of claim 1, wherein the data-processing device receives said measurement data in real time.
23. The filtration monitoring system of claim 1, wherein the measurement data is communicated to the data-processing device wirelessly.
24. The filtration monitoring system of claim 1, wherein the data-processing device is configured to determine the status of the filter element.
25. A single-body sensor component for sensing fluid conditions at a plurality of locations in a filter module, wherein said filter module includes a filter element which receives a fluid in an unfiltered state at an inlet side upstream of the filter element and produces said fluid in a filtered state at an outlet side downstream of the filter element, said sensor component comprising:
- a plurality of sensor packages, each said sensor package including a micro-electromechanical system (MEMS) sensor and being configured to measure at least one of a pressure, temperature, and flow rate at at least one of said locations;
- a plurality of sensor-package receptacles, wherein each said receptacle is configured to selectively receive a respective one of said sensor packages;
- a casing housing said sensor packages and said sensor-package receptacles, said casing defining an aperture in the periphery thereof; and
- a channel fluidly connecting at least one of the sensor packages with said aperture so as to provide fluid communication through the aperture between said at least one of the sensor packages and the fluid.
26. The sensor component of claim 25, wherein said at least one of the sensor packages is ported through said channel to said filtered fluid downstream of the filter element.
27. The sensor component of claim 25, wherein at least one of said plurality of sensor packages is in direct contact with the unfiltered fluid upstream of the filter element.
28. The sensor component of claim 25, wherein each of said sensor packages includes a MEMS pressure sensor.
29. The sensor component of claim 28, wherein each said MEMS pressure sensor is temperature compensated.
30. The sensor component of claim 25, further including means for communicating the respective measurements collected by each of said sensor packages to a data-processing device.
31. The sensor component of claim 30, wherein said communication is conducted wirelessly.
32. The sensor component of claim 30, wherein said communication is conducted in real time.
33. The sensor component of claim 25, wherein each of the plurality of sensor packages includes at least one of a temperature sensor, a flow rate sensor, and a pressure sensor.
34. The sensor component of claim 33, wherein at least one of the plurality of sensor packages includes redundant sensors.
35. The sensor component of claim 34, wherein at least one of the sensor packages includes one or more sensors for measuring one or more of a conductivity, a pH level, and a viscosity of said fluid.
36. The sensor component of claim 25, further including a redundant sensor package.
37. The sensor component of claim 25, wherein each of said plurality of sensor packages includes a plurality of MEMS sensors.
38. The sensor component of claim 25, further including at least one of a visual warning light and an audible alarm configured to indicate an out-of-range condition of said fluid.
39. The sensor component of claim 38, wherein said condition is determined based on measurement of one or more of said fluid's pressure, temperature, flow rate, and differential pressure.
40. The sensor component of claim 38, wherein said visual warning light is disposed proximate a longitudinal end of the sensor component.
41. The sensor component of claim 38, wherein the casing housing the sensor packages and sensor-package receptacles defines circumferential holes through the periphery thereof, and the visual warning light is disposed within said casing so as to provide a visual out-of-range indication through said holes.
42. The sensor component of claim 25, wherein at least one of said plurality of sensor packages is configured to measure at least one parameter selected from the group consisting of a conductivity, a pH level, and a viscosity of the unfiltered fluid.
43. The sensor component of claim 25, further including a processor.
44. The sensor component of claim 43, wherein each said sensor package is configured to take a measurement upon receiving a signal from said processor.
45. The sensor component of claim 25, wherein said filter module further includes a filter manifold, and the single-body sensor component further includes a flange that is disposed around the periphery of said casing so as to lie in a plane perpendicular to the longitudinal axis of the sensor component, said flange being configured to be coupled to said manifold by connecting means.
Type: Application
Filed: Dec 7, 2004
Publication Date: May 26, 2005
Applicant:
Inventors: Daniel Moscaritolo (Newbury Park, CA), Michael Sandford (Oxnard, CA)
Application Number: 11/006,137