Patent Publication Number: US-2021190065-A1

Title: Fluid pumping systems incorporating diaphragm pumps and strain measurement devices

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to fluid pumping systems, and more particularly, but not exclusively, to diaphragm pumps of fluid pumping systems. 
     BACKGROUND 
     Measuring one or more operational characteristics of positive displacement pumps included in fluid pumping systems remains an area of interest. Some existing devices, systems, and/or methods have various shortcomings in certain applications. Accordingly, there remains a need for further contributions in this area of technology. 
     SUMMARY 
     One embodiment of the present disclosure is a unique fluid pumping system including a diaphragm pump and a strain measurement device. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for measuring strain of various components of positive displacement pumps. Further embodiments, forms, features, aspects, benefits, and advantages of the present disclosure shall become apparent from the description and figures provided herewith. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  is a perspective view of a diaphragm pump. 
         FIG. 1B  is a sectional view of a diaphragm pump. 
         FIG. 2  is a diagrammatic view of a fluid pumping system. 
         FIG. 3  is a top view of a strain measurement device bonded to an outlet manifold. 
         FIG. 4  is a top view of a strain measurement device bonded to a fluid cap. 
         FIG. 5  is a schematic view of a sheet including multiple strain measurement devices that may be bonded to the diaphragm pump of  FIG. 1 . 
         FIG. 6  is a diagrammatic view of a control system of the fluid pumping system of  FIG. 2 . 
         FIG. 7  is a simplified block diagram of a method that may be performed by the control system of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. While illustrative embodiments of the invention are described below, in the interest of clarity, not all features of an actual implementation of the invention may be described herein. 
     References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. Additionally, it should be appreciated that items included in a list in the form of “at least one A, B, and C” can mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C). Similarly, items listed in the form of “at least one of A, B, or C” can mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C). 
     In the drawings, some structural or method features, such as those representing devices, modules, instructions blocks and data elements, may be shown in specific arrangements and/or orderings for ease of description. However, it should be appreciated that such specific arrangements and/or orderings may not be required. Rather, in some embodiments, such features may be arranged in a different manner and/or order than shown in the illustrative figures. Additionally, the inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all embodiments and, in some embodiments, may not be included or may be combined with other features. 
     In some embodiments, schematic elements used to represent blocks of a method may be manually performed by a user. In other embodiments, implementation of those schematic elements may be automated using any suitable form of machine-readable instruction, such as software or firmware applications, programs, functions, modules, routines, processes, procedures, plug-ins, applets, widgets, code fragments and/or others, for example, and each such instruction may be implemented using any suitable programming language, library, application programming interface (API), and/or other software development tools. For instance, in some embodiments, the schematic elements may be implemented using Java, C++, and/or other programming languages. Similarly, schematic elements used to represent data or information may be implemented using any suitable electronic arrangement or structure, such as a register, data store, table, record, array, index, hash, map, tree, list, graph, file (of any file type), folder, directory, database, and/or others, for example. 
     Further, in the drawings, where connecting elements, such as solid or dashed lines or arrows, are used to illustrate a connection, relationship, or association between or among two or more other schematic elements, the absence of any such connection elements is not meant to imply that no connection, relationship, or association can exist. In other words, some connections, relationships, or associations between elements may not be shown in the drawings so as not to obscure the disclosure. In addition, for ease of illustration, a single connecting element may be used to represent multiple connections, relationships, or associations between elements. For example, where a connecting element represents a communication of signals, data or instructions, it should be understood by those skilled in the art that such element may represent one or multiple signal paths (e.g., a bus), as may be needed, to effect the communication. 
     Referring now to  FIGS. 1A and 1B , an illustrative fluid displacement device  100  is embodied as, or otherwise includes, a diaphragm pump  102 . As described below, in the illustrative embodiment, the diaphragm pump  102  may be included in a fluid pumping system  200  (see  FIG. 2 ), and the fluid pumping system  200  has a strain measurement device (e.g., the strain measurement device  208 ) that is coupled to the diaphragm pump  102 . The fluid pumping system  200 , and in particular the manner in which the strain measurement device is coupled to, or otherwise provided on, the diaphragm pump  102 , exemplifies one embodiment of the present disclosure. It should be appreciated that in the interest of simplicity and/or clarity, certain features of the illustrative diaphragm pump  102 , such as one or more diaphragms, fluid chambers, shafts, bearings, regulator valves, check valves, fasteners, dividers, covers, etc., for example, may not be depicted in  FIG. 1A . In any case, in an illustrative embodiment, the diaphragm pump  102  may be understood to include fluid chambers  108 ,  110  as shown in  FIG. 1B  that are each fluidly coupled to an inlet (e.g., an inlet manifold  104 ) and an outlet (e.g., an outlet manifold  106 ). In use of the diaphragm pump  102 , fluid supplied to each of the chambers  108 ,  110  via the inlet is pumped to the outlet. In some embodiments, as further discussed below, based on input indicative of one or more operational characteristics associated with each of the chambers  108 ,  110  (e.g., sensor input indicative of fluid pressure output from each chamber  108 ,  110 ), operation of the diaphragm  102  may be evaluated to determine whether one or more fault conditions (e.g., blockages, presence of foreign materials, etc.) are present. 
     The illustrative diaphragm pump  102  is a positive displacement device that is configured to displace or pump fluid provided to an inlet manifold  104  thereof so that the displaced fluid is discharged via an outlet manifold thereof  106 . It should be appreciated that the diaphragm pump  102  depicted in  FIG. 1A  is a nonlimiting example. The diaphragm pump  102  may be embodied as, or otherwise include, any collection of devices (e.g., one or more diaphragms and one or more valves) that are cooperatively capable of pumping fluid provided to the inlet manifold  104  to the outlet manifold  106  in use thereof. In some embodiments, the diaphragm pump  102  may incorporate, or otherwise be embodied as, an arrangement of components in which one side of a diaphragm is sealed with the fluid to be displaced and the other side of the diaphragm is sealed with air or hydraulic fluid (see discussion of actuation devices below). Additionally, in some embodiments, the diaphragm pump  102  may incorporate, or otherwise be embodied as, an arrangement of components in which a diaphragm is moved or flexed via mechanical or electromechanical action and one side of the diaphragm is open to air, or otherwise backed by a fluid of substantially atmospheric pressure. Further, in some embodiments, the diaphragm pump  102  may incorporate, or otherwise be embodied as, an arrangement of components in which one or more diaphragms are unsealed with the fluid to be displaced located on both sides of the one or more diaphragms. Thus, as used herein, the term “pump” and/or the term “diaphragm pump” can include those embodiments having one or more diaphragms which can be driven by any number of actuation devices. Furthermore, unless indicated to the contrary the term “pump” or “diaphragm pump” can refer to individual diaphragm and diaphragm pumping chambers of a multi-diaphragm pumping device, or it can refer to separate standalone pumping devices each having any number of diaphragms. 
     The embodiment depicted in  FIG. 1B  includes two separate diaphragms  111   a  and  111   b , each driven by a common energy source and actuator, where both pumping chambers  108 , 110  are fed by a common inlet manifold  104  (see  FIG. 1A ) and feed a common outlet manifold  106 . The diaphragms can be driven such that one contributes to the outlet manifold  106  while the other is receiving fluid from the inlet manifold  104 , but in some forms it may be possible to operate diaphragm pumps in unison. 
     In the illustrative embodiment of  FIG. 1A , which may exemplify an advantageous implementation of the present disclosure, the diaphragm pump  102  is embodied as, or otherwise includes, one double-diaphragm pump. It should be appreciated that in use of the double-diaphragm pump, movement of diaphragms  111   a  and  111   b  (see  FIG. 1B ) in each of the fluid chambers  108 ,  110  (see  FIG. 1B ) may drive and/or facilitate pumping of fluid through each of the chambers  108 ,  110 . The diaphragms  111   a  and  111   b  can be driven by an actuator  113  (see  FIG. 1B ) which can take a variety of forms as will be appreciated in the discussion below. In the illustrative embodiment, fluid is supplied to each of the fluid chambers  108 ,  110  via the common inlet manifold  104  during use of the pump  102 . Additionally, fluid is pumped through each of the chambers  108 ,  110  to the common outlet manifold  106  during use of the pump  102 . It will be appreciated that the pump depicted in  FIG. 1B  is a nonlimiting example of a double diaphragm pump. 
     Referring now to  FIG. 2 , in the illustrative embodiment, the fluid pumping system  200  includes an energy source  202  and a fluid displacement device arrangement  204  coupled thereto. The energy source  202  is embodied as, or otherwise includes, any drive unit, prime mover, engine, or other source of energy (e.g., rotational power) that is capable of driving the fluid displacement devices included in the arrangement  204 , such as a source of compressed air, electrical energy, and/or rotational power, for example. In the illustrative embodiment, the arrangement  204  includes diaphragm pumps  1  through i, where i may be any suitable integer. Of course, in embodiments in which the arrangement  204  includes one double-diaphragm pump (e.g., the embodiment depicted in  FIG. 1 ), the arrangement  204  may be instead referred to, or otherwise be embodied as, a single diaphragm pump device similar to the diaphragm pump  102 . 
     As depicted in  FIG. 2 , the arrangement  204  includes the diaphragm pump  205 , a second diaphragm pump  212 , and a third diaphragm pump  218 , each of which is driven by the energy source  202  (e.g., mechanical energy source such as provided via a crankshaft or other suitable mechanical linkage, pneumatic energy source such as via a compressor, hydraulic energy source such as through a hydraulic pump, an electrical energy source such as through grid power, etc). It will be appreciated that the pumps  205 ,  212 , and  218  can take the same form and/or include the same variations as those discussed above with respect to pump  102 . Of course, it should be appreciated that in other embodiments, the arrangement  204  may include another suitable number of fluid displacement devices other than the three illustrative diaphragm pumps  205 ,  212 ,  218 . As in any of the embodiments herein, the pumps can be driven to operate in unison with each other in some forms, while in other embodiments the pumps can be driven out of phase with each other to smooth a discharge pressure at an outlet of the pumping system (e.g. an outlet manifold). 
     In the illustrative embodiment, strain measurement devices  208 ,  214 ,  220  are coupled to the diaphragm pumps  205 ,  212 ,  218 . In some embodiments, the strain measurement devices  208 ,  214 ,  220  may each be embodied as, or otherwise include, a single strain measurement device that is coupled to a corresponding one of the diaphragm pumps  205 ,  212 ,  218 . In other embodiments, the strain measurement devices  208 ,  214 ,  220  may each be embodied as, or otherwise include, a collection of strain measurement devices coupled to a corresponding one of the diaphragm pumps  205 ,  212 ,  218 . In any case, each of the illustrative strain measurement devices  208 ,  214 ,  220  is configured to detect a load applied to one or more components of the respective pumps  205 ,  212 ,  218  by the fluid pressure of fluid pumped by the pumps  205 ,  212 ,  218  (e.g., the fluid pressure of the displaced fluid  210 ,  216 ,  222 ). It should be appreciated that at least in some embodiments, each of the illustrative strain measurement devices  208 ,  214 ,  220  may be configured to measure pressure associated with a working fluid of a corresponding one of the diaphragm pumps  205 ,  212 ,  218  (e.g., a pressure associated with working fluid on the backside of a diaphragm of one of the pumps  205 ,  212 ,  218 ). 
     In some embodiments, each of the strain measurement devices  208 ,  214 ,  220  may be embodied as, or otherwise include, a strain gauge. Additionally, in some embodiments, each of the strain measurement devices  208 ,  214 ,  220  may be embodied as, or otherwise include a piezoresistor. Of course, it should be appreciated that in other embodiments, each of the strain measurement devices  208 ,  214 ,  220  may be embodied as, or otherwise include, another suitable device, such as a capacitive strain gauge, a vibrating strain gauge, a microscale strain gauge, a fiber optic sensing strain gauge, a linear strain gauge, a double linear strain gauge, a full bridge strain gauge, a shear strain gauge, a half bridge strain gauge, a column strain gauge, a Rosette strain gauge, or the like, for example. Additionally, it should be appreciated that in other embodiments, any suitable number of strain measurement devices other than the three devices  208 ,  214 ,  220  may be included in the system  200 . 
     Referring now to  FIGS. 3 and 4 , in the illustrative embodiment, the strain measurement devices  208 ,  214 ,  220  are bonded to the respective diaphragm pumps  205 ,  212 ,  218  without being fluidly coupled to the displaced fluid (e.g., fluid  210 ,  216 ,  222 ) so as to avoid exposure of the strain measurement devices  208 ,  214 ,  220  to the displaced fluid in use of the fluid pumping system  200 . Said another way, the strain measurement devices  208 ,  214 ,  220  are bonded to the respective diaphragm pumps  205 ,  212 ,  218  without being fluidly coupled to the displaced fluid so as to resist leakage of fluid from the corresponding pumps  205 ,  212 ,  218  and to avoid interaction between the strain measurement devices  208 ,  214 ,  220  and the displaced fluid in use of the fluid pumping system  200 . Similarly, the strain measurement devices  208 ,  214 ,  220  are bonded to the respective diaphragm pumps  205 ,  212 ,  218  without being fluidly coupled to the working fluid that may pressurize the backside of each diaphragm to avoid interaction between the strain measurement devices  208 ,  214 ,  220  and the working fluid during use of the fluid pumping system  200 . In one embodiment, the strain measurement devices  208 ,  214 ,  220  are mounted to the pumps  205 ,  212 ,  218  to avoid internally contacting the pressure envelope that is inclusive of both the front and back sides of a diaphragm. For example, the strain measurement devices  208 ,  214 ,  220  can be bonded to an exterior of a pipe, conduit, junction, housing, or any other suitable structure that is responsive to pressure produced when pumping fluid with the diaphragm pump(s). The strain measurement devices  208 ,  214 ,  220  could also be coupled to an interior compartment of the pipe, conduit, junction, housing, or any other suitable structure in a manner that does not require direct contact between the devices and the fluid being pumped or the working fluid. For example, the strain measurement devices can be protected in a covering enclosure in some forms such that the devices are not nakedly exposed to the environment. In this way use of the strain measurement devices  208 ,  214 ,  220  permits the pipe, conduit, junction, housing, or other suitable structure to remain without need to breach the structure by forming or drilling a through-hole which would be necessary to insert a traditional pressure transducer for purposes of assessing fluid pressure within the system as a result of operation of the diaphragm pump(s). 
     It should therefore be appreciated that bonding of the strain measurement devices  208 ,  214 ,  220  to the respective diaphragm pumps  205 ,  212 ,  218  does not require, and is not associated with, formation of a port, orifice, aperture, or the like in the diaphragm pumps  205 ,  212 ,  218  which would be associated with traditional pressure transducers that fluidly couples (e.g. fluidly contacts) the pressure sensing devices to the displaced fluid or working fluid. As a result, such bonding resists leakage of the displaced fluid from the diaphragm pumps  205 ,  212 ,  218 , as well as fouling and/or degradation of the devices  208 ,  214 ,  220  that results from, or is otherwise associated with, contact with the fluid (e.g. contact with displaced fluid that breaches a port, orifice, aperture, or the like). In some forms such as those associated with relatively small pumps there may be no space available to form a port, orifice, aperture or the like for use with a traditional pressure transducer, but which the strain measurement devices  208 ,  214 ,  220  are suitable for use. 
     As shown in  FIG. 3 , the strain measurement device  208  is bonded and/or adhered to a conduit  300  of the outlet manifold  106  of the diaphragm pump  205 . Other locations of the strain measurement device(s) are contemplated, such as the inlet manifold in some embodiments. Of course, it should be appreciated that the strain measurement devices  214 ,  220  may be bonded to the corresponding diaphragm pumps  212 ,  218  in a manner substantially identical to the bonding of the device  208  to the conduit  300  as depicted in  FIG. 3 . Regardless, in the illustrative embodiment, the strain measurement device  208  interfaces with the conduit  300  such that the device  208  is not in fluid communication with fluid contained by the conduit  300  to resist exposure of the device  208  to the fluid as discussed above. 
     As shown in  FIG. 4 , in another illustrative mounting location of the strain measurement device  208 , the strain measurement device  208  is bonded to a fluid cap  400  of the diaphragm pump  205 . The fluid cap  400 , along with a diaphragm, defines a pumping chamber (e.g.,  108 ,  FIG. 1B ) through which the displaced fluid passes from the inlet to the outlet. The fluid cap  400  is responsive to pressure fluctuations as a result of fluid passing through the fluid chamber  108 . Of course, it should be appreciated that the strain measurement devices  214 ,  220  may be bonded to the corresponding diaphragm pumps  212 ,  218  in a manner substantially identical to the bonding of the device  208  to the fluid cap  400  as depicted in  FIG. 4 . Regardless, in the illustrative embodiment, the strain measurement device  208  interfaces with the fluid cap  400  such that the device  208  is not in fluid communication with fluid contained by the fluid cap  400  to resist exposure of the device  208  to the fluid as discussed above. 
     Referring now to  FIG. 5 , a sheet  500  that is coupled to a number of strain measurement devices  502  may be bonded to any of the diaphragm pumps discussed herein. The sheet  500  can be made of any suitable type of material, it can take any variety of shapes, and can be coupled to the pump using any suitable technique. It should be appreciated that each of the strain measurement devices  502  may be substantially identical to the aforementioned devices  208 ,  214 ,  220 . In any case, the sheet  500  with the strain measurement devices  502  coupled thereto may be bonded to any of the pumps without being fluidly coupled to the displaced fluid so as to avoid exposure of the strain measurement devices  502  to the displaced fluid. 
     In the illustrative embodiment, when the sheet  500  is bonded to any of the diaphragm pumps  205 ,  212 ,  218 , the strain measurement devices  502  are spaced from one another and configured to provide input data indicative of loads applied at different locations to one or more components of the pumps  205 ,  212 ,  218  by fluid pressure of the displaced fluid. In some embodiments, when the sheet  500  is bonded to any of the diaphragm pumps  205 ,  212 ,  218 , the strain measurement devices  502  may provide input data indicative of loads applied at different circumferential locations around the periphery of a substrate (e.g., an outer diameter of a fluid conduit or fluid cap). Additionally, in some embodiments, when the sheet  500  is bonded to any of the diaphragm pumps  205 ,  212 ,  218 , the input data provided by the strain measurement devices  502  may facilitate identification of stress concentrations at different locations of a substrate, which may enable a quasi-finite element analysis of loads applied to the substrate. Such a sheet  500  can also enable the determination of dead zones or restrictions to fluid owing to the geographic spread of the strain measurement devices  502  around the sheet  500  as well as the comparative assessment of data produced from the strain measurement devices. 
     Referring now to  FIG. 6 , the illustrative fluid pumping system  200  shown in  FIG. 2  can include a control system  600 . In the illustrative embodiment, the control system  600  includes the strain measurement devices  208 ,  214 ,  220 , a controller  602 , fluid displacement device sensors  608 , fluid displacement device actuators  610 , and signal conversion electronics  612 . The strain measurement devices  208 ,  214 ,  220 , the fluid displacement device sensors  608 , the fluid displacement device actuators  610 , and the signal conversion electronics  612  are communicatively coupled to the controller  602 . Additionally, in some embodiments, the control system  600  may include one or more temperature sensors  618  communicatively coupled to the controller  602 . 
     The processor  604  of the illustrative controller  602  may be embodied as, or otherwise include, any type of processor, controller, or other compute circuit capable of performing various tasks such as compute functions and/or controlling the functions of the fluid pumping system  200  (e.g., the diaphragm pumps  205 ,  212 ,  218 ). For example, the processor  604  may be embodied as a single or multi-core processor(s), a microcontroller, or other processor or processing/controlling circuit. In some embodiments, the processor  604  may be embodied as, include, or otherwise be coupled to an FPGA, an application specific integrated circuit (ASIC), reconfigurable hardware or hardware circuitry, or other specialized hardware to facilitate performance of the functions described herein. Additionally, in some embodiments, the processor  604  may be embodied as, or otherwise include, a high-power processor, an accelerator co-processor, or a storage controller. In some embodiments still, the processor  604  may include more than one processor, controller, or compute circuit. 
     The memory device  606  of the illustrative controller  602  may be embodied as any type of volatile (e.g., dynamic random access memory (DRAM), etc.) or non-volatile memory capable of storing data therein. Volatile memory may be embodied as a storage medium that requires power to maintain the state of data stored by the medium. Non-limiting examples of volatile memory may include various types of random access memory (RAM), such as dynamic random access memory (DRAM) or static random access memory (SRAM). One particular type of DRAM that may be used in a memory module is synchronous dynamic random access memory (SDRAM). In particular embodiments, DRAM of a memory component may comply with a standard promulgated by JEDEC, such as JESD79F for DDR SDRAM, JESD79-2F for DDR2 SDRAM, JESD79-3F for DDR3 SDRAM, JESD79-4A for DDR4 SDRAM, JESD209 for Low Power DDR (LPDDR), JESD209-2 for LPDDR2, JESD209-3 for LPDDR3, and JESD209-4 for LPDDR4 (these standards are available at www.jedec.org). Such standards (and similar standards) may be referred to as DDR-based standards and communication interfaces of the storage devices that implement such standards may be referred to as DDR-based interfaces. 
     In some embodiments, the memory device  606  may be embodied as a block addressable memory, such as those based on NAND or NOR technologies. The memory device  606  may also include future generation nonvolatile devices, such as a three dimensional crosspoint memory device, or other byte addressable write-in-place nonvolatile memory devices. In some embodiments, the memory device  606  may be embodied as, or may otherwise include, chalcogenide glass, multi-threshold level NAND flash memory, NOR flash memory, single or multi-level Phase Change Memory (PCM), a resistive memory, nanowire memory, ferroelectric transistor random access memory (FeTRAM), anti-ferroelectric memory, magnetoresistive random access memory (MRAM) memory that incorporates memristor technology, resistive memory including the metal oxide base, the oxygen vacancy base and the conductive bridge Random Access Memory (CB-RAM), or spin transfer torque (STT)-MRAM, a spintronic magnetic junction memory based device, a magnetic tunneling junction (MTJ) based device, a DW (Domain Wall) and SOT (Spin Orbit Transfer) based device, a thyristor based memory device, or a combination of any of the above, or other memory. The memory device may refer to the die itself and/or to a packaged memory product. In some embodiments, 3D crosspoint memory may comprise a transistor-less stackable cross point architecture in which memory cells sit at the intersection of word lines and bit lines and are individually addressable and in which bit storage is based on a change in bulk resistance. 
     The illustrative fluid displacement device sensors  608  may be embodied as, or otherwise include, any collection of devices capable of measuring various operational characteristics of the diaphragm pumps  205 ,  212 ,  218  and providing input data to the controller  602  indicative of the measured operational characteristics. The sensors  608  may be configured to measure operational characteristics associated with one or more diaphragms, fluid chambers, shafts, bearings, regulator valves, check valves, fasteners, dividers, covers, actuators, etc., of the diaphragm pumps  205 ,  212 ,  218 , for example. The illustrative sensors  608  are provided separate from the strain measurement devices  208 ,  214 ,  220  to measure operational characteristics apart from those measured by the strain measurement devices  208 ,  214 ,  220 . Setting forth just a few nonlimiting examples, such sensors  608  can take the form of a position transducer, thermocouple, etc. Of course, it should be appreciated that in some embodiments, the sensors  608  may be omitted from the control system  600 . 
     The illustrative fluid displacement device actuators  610  may be embodied as, or otherwise include, any collection of devices capable of actuating, moving, and/or controlling various components of the diaphragm pumps  205 ,  212 ,  218 . In some embodiments, the actuators  610  may be embodied as, or otherwise include, hydraulic (e.g., hydraulic cylinders), pneumatic (e.g., pneumatic rack and pinion actuators), and/or electric actuators (e.g., solenoids), for instance. Additionally, in some embodiments, the actuators  610  may actuate, move, and/or control various components of the diaphragm pumps  205 ,  212 ,  218  in response to input provided thereto by the controller  602 . As will be appreciated, in some forms the actuators operate to move the diaphragm of the diaphragm pump, with the actuators capable of moving after receipt of power from an energy source input. Such energy source inputs can include electric power, compressed air, etc. as suggested above. The actuator can take the form of a mechanical rod that is reciprocated during operation of the diaphragm pump, but not all embodiments need include a mechanical actuator as will be appreciated with some forms of a pneumatic actuation (e.g. combination of check valves, springs, spool, etc) where a compressed gas is used to inflate/deflate an opposing side of the diaphragm from the fluid chambers  108  and  110 . In these embodiments in which a compressed gas or other fluid is used as a working fluid actuator to inflate/deflate the diaphragm for the purpose of pumping, strain measurements can also be taken using strain measurement sensors as described above to assess the pressure change of the chamber which receives the compressed gas or other working fluid. 
     The illustrative signal conversion electronics  612  may be embodied as, or otherwise include, any collection of devices cooperatively capable of converting one or more raw signals from the strain measurement devices  208 ,  214 ,  220  to input data that may be thereafter provided to the controller  602 . In the illustrative embodiment, the signal conversion electronics  612  include one or more Wheatstone bridges  614  and one or more instrumentation amplifiers  616 . The Wheatstone bridge(s)  614  may each be embodied as, or otherwise include, an electrical circuit configured to measure an unknown electrical resistance value. The instrumentation amplifier(s)  616  may each be embodied as, or otherwise include, an electrical circuit configured to increase the power of a time-varying voltage or current signal. 
     In some forms the strain measurement devices  208 ,  214 ,  220  can be self-powered in lieu of being powered by a traditional power supply. Such devices can be self-powered by extracting pressure ripple energy associated with the periodic pulsing nature of the diaphragm pump. Such devices could be coupled to structure that are in areas inaccessible or inhospitable to wires. These devices may be further constructed having near field communication (NFC) or other type of wireless transmission that allows for pressure data accumulation and gathering. The strain measurement devices  208 ,  214 ,  220  can be configured to provide NFC whether or not they are self-powered. 
     The temperature sensor(s)  618  may each be embodied as, or otherwise include, any device or collection of devices configured to measure temperature of fluid contained in the diaphragm pumps  205 ,  212 ,  218  and provide input data to the controller  602  indicative of the measured temperature. In some embodiments, as described below with reference to  FIG. 7 , input data provided by the temperature sensor(s)  618  may be considered in combination with input data provided by the strain measurement devices  208 ,  214 ,  220  to determine one of more parameters associated with fluid contained in the diaphragm pumps  205 ,  212 ,  218 , such as a viscosity of the fluid, for example. In such embodiments, the temperature sensor(s)  618  may be coupled to one or more of the diaphragm pumps  205 ,  212 ,  218  such that the temperature sensor(s)  618  are not fluidly coupled and/or exposed to working fluid pumped by the one or more pumps  205 ,  212 ,  218 , thereby facilitating temperature measurement with a substantially and/or completed closed pressure envelope. 
     Referring now to  FIG. 7 , an illustrative method  700  of operating the fluid pumping system may be embodied as, or otherwise include, a set of instructions that are executable by the control system. The method  700  corresponds to, or is otherwise associated with, performance of the blocks described below in the illustrative sequence of  FIG. 7 . It should be appreciated, however, that the method  700  may be performed in one or more sequences different from the illustrative sequence. 
     The illustrative method  700  begins with block  702 . In block  702 , the controller receives input data from the strain measurement devices (e.g., the strain measurement devices  208 ,  214 ,  220  shown in  FIG. 2 ). To do so, in the illustrative embodiment, the controller  602  performs block  704 . In block  704 , the controller converts one or more raw signals from the strain measurement devices to the input data via the Wheatstone bridge(s)  614  and the instrumentation amplifier(s). From block  702 , the method  700  subsequently proceeds to block  706 . 
     In block  706  of the illustrative method  700 , the controller determines operational and/or performance characteristics of the diaphragm pumps (e.g., the diaphragm pumps  205 ,  212 ,  218  shown in  FIG. 2 ) based on the input data received in block  702 . To do so, at least in some embodiments, the controller performs one or more of blocks  708 ,  710 ,  712 ,  714 ,  716 , and  720 . 
     In block  708  of the illustrative method  700 , the controller determines fluid pressures of the displaced fluid and/or rates of change in fluid pressures of the displaced fluid based on the input data. In some embodiments, the fluid pressures and/or rates of change thereof determined in block  708  may be used to compare localized fluid pressures within the diaphragm pumps, such as fluid pressures in respective first and second fluid cavities (e.g., the fluid chambers  108 ,  110  shown in  FIG. 1B ) of each of the diaphragms pumps, for example. In such embodiments, the controller may compare electrical signals representative of fluid pressures on the basis of signal characteristics such as amplitude, frequency, shape, and phase shift, among other things. It should be appreciated that faults, such as undesired stretching and/or degradation of the diaphragms, binding and/or malfunctioning of one or more valves, an incomplete stroke of the diaphragms, or leakage in one or more valves (e.g., leakage between the ball of a joint and a seat of a check valve), for example, may be diagnosed based on such comparisons between the pressure curve measured for the first and second cavities. Other faults capable of being assessed (such as by evaluating rate of change in pressure) using the devices and techniques herein include line breakage, line blockage, and fluid consistency. In some embodiments, pressure curves (e.g. time history pressure data and/or calculated signal characteristics such as amplitude, frequency, phase, power spectral density, rate of change, etc.) associated with each cavity or chamber of a diaphragm pump (e.g, one of the pumps  205 ,  212 ,  218 ) may be compared to one another, compared to historic data, or compared to an expected performance curve, to diagnosis faults as discussed above. Additionally and/or alternatively, pressure curves (e.g. time history pressure data and/or calculated signal characteristics such as amplitude, frequency, phase, power spectral density, rate of change, etc.) associated with conduits, valves, or junctions in fluid communication with the diaphragm pump (e.g, one of the pumps  205 ,  212 ,  218 ) may be evaluated to diagnosis faults as discussed above. It will be appreciated that a pressure ripple present in the diaphragm pumping systems disclosed herein are indirectly sensed by the strain measurement devices to provide the pressure curve data which can be evaluated. Pressure ripples can be very small to very large, the degree of which can depend on the number of moving parts in the system. 
     To set forth just a few nonlimiting examples, in a double diaphragm pump in which the pumping chambers operate 180 degrees out of phase, the pressure curve associated with pumping chamber  108  can be compared with the pressure curve associated with pumping chamber  110 . The comparison can include differencing and/or ratioing a pressure curve associated each chamber  108  and  110  and comparing the difference and/or ratio to a threshold or range. If the difference does not exceed the threshold, no fault signal is generated. If the difference exceeds the threshold, the controller can generate a fault signal useful to prompt service or maintenance of the pump. In some forms more than one threshold can be utilized with different fault signals generated based on the threshold. 
     In another form, time history data can be phase shifted to permit a comparison. In still another form, phase shifted time history data can be differenced to form an error, and the error data can be evaluated over a period of time before generating a fault signal. In still other forms, multiple assessments can be performed which together are used to form an aggregate score of system health, with a threshold applied to the aggregate score to determine whether a fault signal should be generated. As will be appreciated, pressure curve data can be collected and analyzed continuously and/or periodically. Such data can furthermore be transmitted in real time, or it can be transmitted only upon occurrence of a fault condition. In those instances where data is only transmitted upon occurrence of a fault, any amount of data can be transmitted. For example, time history data can be transmitted in the period leading up to the fault, as well as any calculated data that may have been determined from the time history data leading up to the fault. 
     In any of the approaches discussed above, data converted to absolute pressure can be useful, but is not needed in all embodiments. Comparisons that rely upon relative pressure values are also useful. 
     In block  710  of the illustrative method  700 , the controller  602  determines cavitation in one or more diaphragm pumps based on the input data. It should be appreciated that a determination of cavitation in block  710  by the controller  602  may include, be accompanied by, or otherwise be embodied as, generation of an alert or fault notification which may be displayed via a display of a user interface (not shown). It should be appreciated that in some embodiments, a sheet including or coupled to multiple strain measurement devices (e.g., the sheet  500  shown in  FIG. 5 ) may be coupled to the one or more diaphragm pumps to determine cavitation in block  710 . 
     In block  712  of the illustrative method  700 , the controller determines flow differentials of displaced fluid in one or more diaphragm pumps based on the input data. In some embodiments, determination of the flow differentials in block  712  by the controller may include, be accompanied by, or otherwise be embodied as, mapping fluid pressures within each of the diaphragm pumps, and in particular, mapping fluid pressures within each fluid cavity of each diaphragm pump. It should be appreciated that in some embodiments, the determination of flow differentials may be used to diagnose and/or identify irregularities or abnormalities occurring during operation of the one or more diaphragm pumps. 
     In block  714  of the illustrative method  700 , the controller determines pressure gradients of displaced fluid in one or more diaphragm pumps based on the input data. In some embodiments, determination of the pressure gradients in block  714  by the controller may include, be accompanied by, or otherwise be embodied as, the determination of pressure gradients in each diaphragm pump that are measured between the inlet (e.g., the inlet manifold  104  shown in  FIG. 1A ) and the outlet (e.g., the outlet manifold  106 ) thereof. Pressure and pressure buildup/gradient can be the result of restriction of flow, and therefore a source of loss of energy or inefficiency. Balancing the pressure gradient across a whole pump and system depending on running conditions (viscosity or sludge content etc) of the fluid of the pump can result in pumping any fluid the most energy efficient way. The controller can be structured to adjust pumping based upon pressure gradient. 
     In block  716  of the illustrative method  700 , the controller  602  determines the viscosity of the displaced fluid in one or more diaphragm pumps based at least partially on the input data. In some embodiments, the determination made by the controller in block  716  may be based on input data provided by one or more temperature sensors (e.g., the temperature sensor(s)  618  shown in  FIG. 6 ). 
     It should be appreciated that in some embodiments, block  706  may include, or otherwise be embodied, other determinations in addition to, or as an alternative to, the determinations associated with blocks  708 ,  710 ,  712 ,  714 ,  716 . Additionally, it should be appreciated that in some embodiments, one or more of the blocks  708 ,  710 ,  712 ,  714 ,  716  may be omitted from the block  706 . In any case, from block  706 , the method  700  subsequently proceeds to block  718 . 
     In block  718  of the illustrative method  700 , the controller controls one or more of the diaphragm pumps in response to the determinations made in block  706 . In doing so, the controller may adjust signals output to fluid displacement device actuators (e.g., the fluid displacement device actuators  610 ), adjust air and/or fluid pressures of fluid supply valves, regulators, distributors, etc., and perform calculations to assess operational characteristics such as flow (e.g., flow estimates based on pressure ripple) and dosing, for example. In some embodiments, in block  718 , the controller may generate a notification to alert an operator or technician of a fault condition associated with one or more of the diaphragm pumps (e.g., a degraded diaphragm, a fluid cavity blockage, an under-pressurized or over-pressurized air valve) or the energy source driving the one or more diaphragm pumps (e.g., an inadequate or excessive motor speed). Further, one or more of the activities listed within block  706  can be performed manually. For example, strain information made available via block  702  can be used to compute flow differentials, with the ultimate conclusion of, say, a leaking diaphragm can be expressed as an alert (visual, aural, etc.) to a user. The control system is also structured to incorporate information from fluid displacement sensors  608  ( FIG. 6 ) to augment the strain information. Such incorporation of fluid displacement sensors  608  can be used to confirm a diagnosis made available from the strain information. 
     In some embodiments the controller can adjust operation of the diaphragm pump in  718  based upon temperature of the displaced fluid. For example, if temperature of the fluid being pumped can be sensed or estimated, the temperature could help determine viscosity of the displaced fluid (e.g. calculated, determined from a look up table, etc.). In this situation the pressure ripple or pressure curve data evaluation above could help provide feedback whether the pump is pumping too fast or hard. The pump flow could be optimized depending on the fluid, and in some forms the controller can protect the pump in situations in which fluid has become too viscous, frozen or solid in the pump. For example, a “do not start/continue” safety interlock can be used to prevent pump damage. 
     In an embodiment which includes multiple separate pumps, pressure ripple and pressure curve data can be used to adjust the drive mechanism for one or all of the separate pumps. In this manner the pressure ripple train can be shifted and moved relative to each pump. The effect could be that the controller is able to sequence and shift the system pressure ripple as to minimize the overall combined outlet pressure ripple, thus producing smoother flow. 
     It will be appreciated that the description above with respect to the various pumps in  FIGS. 3-7  as applied to the multi-pump embodiment depicted in  FIG. 2  is equally applicable to the embodiments of the pump depicted in  FIGS. 1A and 1B . 
     One aspect of the present disclosure includes a fluid pumping system comprising a diaphragm pump configured to displace fluid provided to an inlet thereof so that the displaced fluid is discharged via an outlet thereof, and a strain measurement device coupled to the diaphragm pump and configured to detect a load applied to at least one component of the diaphragm pump by fluid pressure of the displaced fluid, wherein the strain measurement device is bonded to the diaphragm pump without being fluidly coupled to the displaced fluid so as to avoid exposure of the strain measurement device to the displaced fluid during use of the fluid pumping system. 
     A feature of the present disclosure further includes a control system including the strain measurement device and a controller communicatively coupled to the strain measurement device, wherein the controller includes memory having instructions stored therein that are executable by a processor to cause the processor to receive input data from the strain measurement device, to determine the fluid pressure of the displaced fluid based on the input data, and to control the fluid pumping system in response to the determination of the fluid pressure of the displaced fluid. 
     Another feature of the present disclosure includes wherein the control system includes a Wheatstone bridge and an instrumentation amplifier, and wherein to receive the input data from the strain measurement device, the instructions stored in the memory are executable by the processor to cause the processor to convert one or more raw signals from the strain measurement device to the input data via the Wheatstone bridge and the instrumentation amplifier. 
     Yet another feature of the present disclosure includes wherein the strain measurement device is bonded to a conduit that extends to the outlet of the diaphragm pump. 
     Still another feature of the present disclosure includes wherein the controller is structured to perform a diagnostic evaluation of the diaphragm pump based upon data derived from the strain measurement device, the diagnostic evaluation including one of: identifying a blockage in a fluid flow passage associated with fluid capable of being displaced by the diaphragm pump, identifying an off-nominal performance in a diaphragm of the diaphragm pump, identifying an off-nominal performance of an actuating mechanism used to drive the diaphragm of the diaphragm pump. 
     Yet still another feature of the present disclosure includes wherein the strain measurement device is bonded to a fluid cap of the diaphragm pump, and which further includes a control system useful to evaluate data generated from the strain measurement device and determine an operational performance degradation in the diaphragm pump through evaluation of a ripple in the data caused by periodic cycling of a diaphragm. 
     Still yet another feature of the present disclosure includes wherein the strain measurement device interfaces with the fluid cap such that the strain measurement device is not in fluid communication with fluid contained by the fluid cap, and wherein the diaphragm pump is a double diaphragm pump having two separate diaphragm pumping chambers structured to actuate out of phase with one another such that the first of the two separate diaphragm pumping chambers expels fluid while the other of the two separate diaphragm pumping chambers intakes fluid. 
     A further feature of the present disclosure includes wherein the strain measurement device is configured to provide input data upon which a determination of at least one the following may be based: fluid pressure of the displaced fluid; a rate of change of fluid pressure of the displaced fluid; cavitation within the diaphragm pump; a flow differential of the displaced fluid; a pressure gradient of the displaced fluid; a viscosity of the displaced fluid; an off-nominal actuator performance of an actuator used to drive a diaphragm of the diaphragm pump; an off-nominal diaphragm of the diaphragm pump; a blockage of the diaphragm pump, and which further includes an energy source useful to provide motive force to the diaphragm of the diaphragm pump, the energy source including at least one of pneumatic, hydraulic, and electric. 
     Another aspect of the present disclosure provides a fluid pumping system comprising: a diaphragm pump configured to displace fluid provided to an inlet of the diaphragm pump so that the displaced fluid is discharged via an outlet of the diaphragm pump, the diaphragm pump including at least two diaphragms, each diaphragm at least partially defining a fluid cavity through which at least some of the displaced fluid travels between the inlet and the outlet, and at least two strain measurement devices coupled to the diaphragm pump, each strain measurement device configured to detect a load applied by fluid pressure of the displaced fluid, wherein each of the strain measurement devices is bonded to the diaphragm pump without being fluidly coupled to the displaced fluid so as to resist leakage of fluid from the diaphragm pump and to avoid interaction between each strain measurement device and the displaced fluid during use of the fluid pumping system. 
     A feature of the present disclosure further includes a control system including the strain measurement devices and a controller communicatively coupled to the strain measurement devices, wherein the controller includes memory having instructions stored therein that are executable by a processor to cause the processor to receive input data from the strain measurement devices, to determine the fluid pressure of the displaced fluid in the diaphragm pump based on the input data, and to control the fluid pumping system in response to the determination of the fluid pressure of the displaced fluid. 
     Another feature of the present disclosure includes wherein the control system includes a Wheatstone bridge and an instrumentation amplifier, and wherein to receive the input data from the strain measurement devices, the instructions stored in the memory are executable by the processor to cause the processor to convert raw signals from the strain measurement devices to the input data via the Wheatstone bridge and the instrumentation amplifier. 
     Still another feature of the present disclosure includes wherein the at least two strain measurement devices are arranged adjacent to the inlet and the outlet, respectively, to measure a pressure change across the diaphragm pump. 
     Yet another feature of the present disclosure includes wherein the at least two strain measurement devices are each arranged on a fluid cap associated with one of the fluid cavities. 
     Still yet another feature of the present disclosure includes wherein the at least two strain measurement devices are configured to provide strain data upon which an evaluation of component performance is determined, the component performance includes at least one of an actuator performance, a diaphragm performance, and an actuating mechanism performance. 
     Yet still another feature of the present disclosure includes wherein each fluid cavity is at least partially defined by a fluid cap, and wherein the at least two strain measurement devices are arranged on respective fluid caps. 
     A further feature of the present disclosure includes wherein a control system of the fluid pumping system is configured to compare an input from the at least two strain measurement devices to look for imbalanced flow through the fluid cavities. 
     Yet another aspect of the present application includes a fluid pumping system comprising: a diaphragm pump configured to displace fluid provided to an inlet thereof so that the displaced fluid is discharged via an outlet thereof, and a control system including a strain measurement device and a controller communicatively coupled to the strain measurement device, wherein the controller includes memory having instructions stored therein that are executable by a processor to cause the processor to receive input data from the strain measurement device, to determine a fluid pressure of the displaced fluid based on the input data, and to control the fluid pumping system in response to the determination of the fluid pressure of the displaced fluid. 
     A feature of the present disclosure includes wherein the control system includes a Wheatstone bridge and an instrumentation amplifier; wherein to receive the input data from the strain measurement device, the instructions stored in the memory are executable by the processor to cause the processor to convert one or more raw signals from the strain measurement device to the input data via the Wheatstone bridge and the instrumentation amplifier; and wherein the diaphragm pump is structured to have a variable pumping speed. 
     Another feature of the present disclosure includes wherein the strain measurement device is coupled to a sheet that is bonded to the diaphragm pump without being fluidly coupled to the displaced fluid so as to avoid exposure of the strain measurement device to the displaced fluid in use of the fluid pumping system. 
     Still another feature of the present disclosure further includes a plurality of strain measurement devices coupled to the sheet, wherein when the sheet is bonded to the diaphragm pump, the plurality of strain measurement devices are spaced from one another and configured to provide input data indicative of loads applied at different locations to one or more components of the diaphragm pump by fluid pressure of the displaced fluid. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. 
     In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     In some situations, it may be desirable to provide, or otherwise achieve, better control of positive fluid displacement devices such as diaphragm pumps (e.g., the pumps  205 ,  212 ,  218 ) by monitoring pressure signals associated with fluid pumped by those devices. That information may be provided to users and/or in the form of feedback signals for control systems. Depending on the application, compatibility of the pumped fluid of positive fluid displacement devices with the materials of construction of those devices may be a concern, particularly in the case of acidic and caustic fluids. Furthermore, depending on the application, compatibility of one or more sensing elements with the pumped fluid may be taken into consideration, particularly in the event of a containment system breach or other fluid leakage event. Such compatibility concerns may be addressed and/or avoided by utilizing sensing elements (e.g., the strain measurement devices  208 ,  214 ,  220 ) coupled to containment systems (e.g., the manifolds  104 ,  106  and the fluid cap  400 ) as contemplated by the present disclosure. 
     It should be appreciated that the raw signal data provided by the illustrative strain measurement devices may be scaled (e.g., via a constant scaling factor) to establish and/or calculate pressure measurements based thereon. Additionally, it should be appreciated that such scaling may be based on, or determined according to, the coupling location of the strain measurement devices to the containment systems of the positive fluid displacement devices. The input data provided by the strain measurement devices, which may correspond to raw signal data scaled as discussed above, may correlate closely and/or substantially align with, actual pressure measurements provided by one or more pressure transducers, at least in some embodiments. 
     Fluid pressure in electric reciprocating pumps, for example, may be a function of actuator position and the application of torque, which may pose measurement difficulties. In conventional configurations, a pressure transducer may be provided as an add-on component to sense the fluid pressure in the fluid containment system of the pump. 
     Depending on the chemical compatibility needs of the user, pumps may incorporate various materials of construction. Conventional pressure transducers may not suffice to satisfy the chemical compatibility needs of the user. Depending on the application, the pumped fluid may damage the transducer, and attachment of the transducer to the pump may pose issues, such as contamination and/or introduction of foreign materials, for example. More specifically, such attachment may require a fluid coupling with, or a connection into, the fluid containment system, which may introduce leak paths and/or weaken the fluid containment system. The present disclosure may address the objective of accurately measuring pump pressure regardless of the pumped working fluid and without breaching the fluid containment system environment. 
     The strain measurement devices of the present disclosure may have no contact with the pumped fluid. Additionally, those strain measurement devices (i.e., attachment of those devices to the pumps) may create no fluid leakage points. In some embodiments, each diaphragm of a diaphragm pump may include at least one strain measurement device. Additionally, in some embodiments, each diaphragm pump may include a strain measurement device positioned at an inlet and at an outlet thereof. Of course, it should be appreciated that the teachings of the present disclosure may be applied to all positive displacement pumps, and not limited to diaphragm pumps.