Piston limit sensing and software control for fluid application

A liquid delivery system is presented. The liquid delivery system comprises a source of fluid coupled to an outlet. The liquid delivery system also includes a hydraulic cylinder coupled to the source of fluid. The hydraulic cylinder has a piston movable between a first limit position and a second limit position during an operational cycle. The hydraulic cylinder is configured to pressurize fluid received from the source of fluid, and deliver the pressurized fluid to the outlet. The liquid delivery system also comprises a rod connected to the piston and extending out of the cylinder. The liquid delivery system also comprises a sensor configured to sense a position of the rod to provide a signal indication of the piston with respect to the first position or the second position. An indication of the sensed position is provided to a controller, and the controller is configured to send a control signal to initiate a normal operation loop based on the sensed position.

BACKGROUND

Liquid delivery systems are used to deliver fluid from a source location to a delivery location. In some instances, liquid delivery systems include a pump system configured to provide the liquid at a desired operational pressure. Liquid delivery systems are useful for a variety of fluids, for example paints, primers, and other exemplary fluids.

SUMMARY

A liquid delivery system is presented. The liquid delivery system comprises a source of fluid coupled to an outlet. The liquid delivery system also includes a hydraulic cylinder coupled to the source of fluid. The hydraulic cylinder has a piston movable between a first limit position and a second limit position during an operational cycle. The hydraulic cylinder is configured to pressurize fluid received from the source of fluid, and deliver the pressurized fluid to the outlet. The liquid delivery system also comprises a rod connected to the piston and extending out of the cylinder. The liquid delivery system also comprises a sensor configured to sense a position of the rod to provide a signal indication of the piston with respect to the first position or the second position. An indication of the sensed position is provided to a controller, and the controller is configured to send a control signal to initiate a normal operation loop based on the sensed position.

DETAILED DESCRIPTION

The present disclosure relates to liquid pumps, and more specifically, to a limit sensing system used to determine the position of a piston in a liquid delivery system. Position sensing can provide instantaneous analog or digital electronic position feedback information about the piston within a cylinder.

Aspects of the present disclosure relate to hydraulic powered liquid pumps, more particular aspects relate to a limit sensing system used to determine the position of a piston in a liquid delivery system, and control thereof. While the present disclosure is not necessarily limited to such applications, various aspects of the disclosure may be appreciated through a discussion of various examples using paint as context.

According to various embodiments, the liquid delivery system can include a hydraulic cylinder. The hydraulic cylinder can be a mechanical actuator that distributes a force on a liquid using reciprocating piston strokes. The piston is connected to a piston rod or other suitable structure and movement of the piston causes the reciprocal movement of the piston rod. The cylinder is closed on one end by a cylinder top (hereinafter referred to as the head) and on the other end by a cylinder bottom (hereinafter referred to as the base) where the piston rod comes out of the cylinder. In a hydraulic powered liquid delivery system, the hydraulic cylinder derives its power from a pressurized hydraulic fluid. In certain embodiments, an actuator (e.g., a solenoid valve) can direct the hydraulic fluid flow generated by a hydraulic pump through a first port (e.g., a port near the head hereinafter referred to as the head port) located on the cylinder. As the hydraulic fluid is directed by the actuator to the head port, pressure builds in the cylinder to force the piston to move from the head, through the cylinder, and to the base.

In various embodiments, a limit sensing system can be used to detect that the piston has reached the end of its stroke. The limit sensing system can include a magnet and reed switches. The magnet and reed switches may be controlled by a MOSFET (metal-oxide semiconductor field-effect transistor) and flip-flop integrated circuit system, in one example. In another example, the limit sensing system is controlled by a processor and integrated software. One advantage of software-based control, with hydraulic pump systems, is the ability to verify sensor functionality and detect a piston location prior to start-up. Integrated software may be configured to start a normal operational loop based on a detected location of the piston within the loop. The use of software-based control also allows for other additional software control features, for example a total cycle counter, real-time cycle rate tracking, real-time gallons-per-minute tracking, total gallons pumped, and/or run-time tracking. Information concerning such features may be downloadable to a separate computing device, for example, allowing for parameter tracking over the lifetime of a system. Software-based control may also comprise live cycle rate counting, which may enable tracking and updating of pump cycles per minute. This may enable performance tracking without additional hardware configured to manually count cycles.

During each piston stroke, a portion of the piston rod remains outside the cylinder, regardless of the location of the piston inside the cylinder. In particular embodiments, the magnet is located on this portion of the piston rod (on the opposite side of the base of the cylinder as the piston), enabling the magnet to remain outside the cylinder as well. When the piston has completed a stroke, the magnetic field created by the magnet causes the reed switch to change state. The reed switch can be connected to an electrical circuit that can feed logic gates that enable the actuator to direct the hydraulic fluid through the valve into a second port (e.g., a port near the base hereinafter referred to as the rod port) located on the cylinder. The reed switch can also be connected, in another example, to a controller, such that data concerning piston location, reed switch state, and magnetic field can be reported and/or stored over time, allowing for system performance tracking. As the hydraulic fluid is directed by the actuator to the rod port, pressure builds in the cylinder to force the piston to move from the base, through the cylinder, and to the head. During this process, the hydraulic fluid is forced into the head port, back into the actuator, and returned to a hydraulic fluid reservoir. As the piston moves from the base to the head, the magnetic field applied to the reed switch decreases and the reed switch will change its state (open if application of the magnetic field forced it to close and close if application of the magnetic field forced it to open). As the piston draws near the head and approaches the second reed switch, its magnetic field causes the second reed switch to change its state.

In various embodiments, since the magnet is located on the portion of the piston rod that is outside of the cylinder, the magnet is not exposed to the pressurized hydraulic fluid inside the cylinder. This may protect the magnet from damage and corrosion that could occur from exposure to the hydraulic fluid if the magnet was located in the cylinder (e.g., on the piston). Moreover, if the magnet becomes damaged (e.g., cracked or has depleted magnetic properties), it may need to be repaired or replaced. However, because the magnet is located outside the cylinder, the hydraulic pump does not need to be disassembled to repair or replace the magnet.

According to particular embodiments, the reed switches may also be located outside the cylinder. As a result, in a paint delivery system, the reed switches, reed switch connectors, and an electrical circuit board may be exposed to paint. In particular embodiments, the reed switches and the reed switch connectors can be hermetically sealed and the electrical circuit board can be enclosed to protect them from damage, corrosion, and depletion of sensor properties that may be caused from exposure to the paint.

A controller may be located proximate the cylinder, in one example, and may be responsible for control of the piston rod. In another example, the controller may be located elsewhere within the pump system, such that commands are generated by the controller, and received by a receiving component proximate the piston rod.

Embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures. However, there can be several embodiments of the present invention and the present invention is not limited to the embodiments set forth herein. The embodiments disclosed are provided so that this disclosure can fully convey the scope of the invention to those skilled in the art. For example, in another embodiment, the reed switch state is monitored by a processor. Therefore, the following detailed description is not to be taken in a limiting sense.

FIG. 1depicts a painting system in accordance with an embodiment of the present invention. Painting system100that includes an upper shroud126, a frame128, wheels130, a lower shroud132, a motor system102, a solenoid valve (not shown inFIG. 1) under the lower shroud132, a pump assembly106, a hydraulic motor136, and a paint reservoir (not shown). Motor system102can be electrically powered, gas powered, etc. and can include a hydraulic pump140under lower shroud132and a hydraulic fluid reservoir (not shown inFIG. 1) also under lower shroud132. The hydraulic pump delivers hydraulic fluid (e.g., oil) from the hydraulic fluid reservoir to the solenoid valve. The solenoid valve can be an electromechanical device that includes a solenoid, a head port on the valve body and a rod port on the valve body. The head port on the valve body and the rod port on the valve body can be controlled by an electric current through the solenoid. For the solenoid valve, the electric current can alternate the flow from the head port on the valve body and the rod port on the valve body.

In one example, the solenoid is coupled to a controller140. In one example, the controller comprises a MOSFET and flip-flop integrated circuit system. In another example, the solenoid is controlled by a computer processor and integrated software, for example a circuit board. The circuit board may be communicably coupled, directly to the solenoid. In one example, the controller is also coupled to a memory, such that the controller can report, or store, collected information from a cycle counter and/or a run-time tracker. The controller may be useful to measure performance of the pump system without manual cycle counting.

According to various embodiments, pump assembly106includes a hydraulic cylinder114and a paint pump116. The solenoid valve directs the hydraulic fluid, generated by the hydraulic pump, through the head port on the valve body to a head port122of hydraulic cylinder114. As the hydraulic fluid is directed by the solenoid valve through head port122of hydraulic cylinder114, pressure builds in the cylinder and forces the hydraulic piston to move. As the hydraulic piston moves through cylinder, the hydraulic fluid is forced through a rod port124of hydraulic cylinder114, into the solenoid valve through the rod port on the valve body, and returned to the hydraulic fluid reservoir. In addition, a hydraulic piston rod (not shown inFIG. 1), connected to the hydraulic piston, can also be connected to a paint piston rod (not shown inFIG. 1). As a result, the hydraulic piston moves the paint piston rod through paint pump116to pump paint from the paint reservoir to an outlet hose134connected to a paint applicator (not shown inFIG. 1).

In particular embodiments, a magnet is connected to the hydraulic piston rod. Moreover, at least two sensors are located outside the cylinder that correspond to the two limit positions of the hydraulic piston at each end of its stroke, hereinafter referred to as a stroke limit position. In certain embodiments, the sensor can be a reed switch. A reed switch is an electrical switch operated by an applied magnetic field. It may consist of a pair of contacts on reeds in a hermetically sealed airtight envelope constructed from a suitable material, such as glass or plastic. In certain embodiments, the contacts can be open, making no electrical contact. The switch can be closed by bringing the magnet near the switch. Once the magnet is pulled away, the reed switch will open again. In other embodiments, the contacts can be closed and the switch can be opened by bringing the magnet near the switch. Once the magnetic field is removed, the reed switch closes.

In one example, one or more limit sensors are coupled to a controller (not shown inFIG. 1). The controller may, using the one or more limit sensors, detect a position of the piston rod. Detecting a position of the piston rod, during start-up for example, may be helpful to start a normal operation loop. In some previous systems, uncertainty in piston-location can make starting a normal operation loop difficult. For example, the piston may be mid-stroke, topped out, bottomed out, etc. The software-controlled controller may be able to detect a location of the piston, and engage a corresponding operation loop.

The controller may also be configured to track cycles, for example by updating a cycle-rate count after each completed cycle, and run-time for the pump system. This may allow for calculation of performance parameters without adding additional hardware to the pump system to manually count cycles.

For example, as the hydraulic piston moves from the head through the cylinder, a magnet located on the hydraulic piston rod moves closer to a first reed switch. When the hydraulic piston has reached a stroke limit position in the cylinder, the magnetic field closes the first reed switch and completes an electrical circuit (not shown inFIG. 1). In an example using a MOSFET and flip-flop integrated circuit control system, the electrical circuit can provide a voltage or other suitable indication that activates a set of metal oxide semiconductor field effect transistors (MOSFETs) and flip-flop integrated circuit, or other suitable switching devices, to change the state of the solenoid. In another example, the controller comprises integrated software configured to change the state of the solenoid. Once the solenoid state changes, the hydraulic fluid can now be released from the rod port on the valve body, into the cylinder through rod port124of hydraulic cylinder114. As the hydraulic piston moves through the cylinder in the opposite direction, the magnetic field strength, with respect to the first reed switch, decreases and the first reed switch opens. Moreover, the hydraulic fluid can be pushed back through head port122of hydraulic cylinder114, into the solenoid valve through the head port on the valve body, and returned to the hydraulic fluid reservoir. The paint piston rod can then move through paint pump116and continue to pump paint from the paint reservoir. When the hydraulic piston has reached a stroke limit position, the magnetic field causes a second reed switch to close, thereby completing the electrical circuit, and reverse the hydraulic fluid flow from the solenoid valve.

In another embodiment, a hall-effect sensor system can be used to determine when the hydraulic piston has reached the end of a piston stroke. A hall-effect sensor system can include a magnet and a sensor. In various embodiments, the hall-effect sensor system can be hermetically sealed or enclosed. The sensor can be a transducer that varies its output voltage in response to an applied magnetic field produced by the magnet. When the hydraulic piston has reached a stroke limit position, the magnet is located at a position such that its magnetic field is perpendicular with respect to the sensor. The perpendicular magnetic field can induce the output voltage from the sensor that enables the solenoid valve to alternate the flow of the hydraulic fluid. In one example, the hall-effect sensor is communicably coupled to a controller, such that the controller can detect a current position of the piston within an operational loop, during start-up, for example.

In another embodiment, a photoelectric sensor is used to determine that the hydraulic piston has reached a stroke limit position. A photoelectric sensor is a device used to detect the distance, absence, or presence of an object by using a light transmitter and a photoelectric receiver. In yet further embodiments, other sensors can be used that include, but are not limited to, mechanical sensors, base active transducer sensors, eddy-current sensors, inductive position sensors, photodiode array sensors, and proximity sensors. In particular embodiments, the sensor systems can be hermetically sealed or enclosed to protect them from exposure to the paint. In one example, the photoelectric sensor is communicably coupled to a controller, such that the controller can detect a current position of the piston within an operational loop.

However, in other embodiments, other suitable sensors may be used. In another embodiment, an anisotropic magneto-resistive (AMR) magnetic sensor is used. In a further embodiment, a giant magneto-resistive (GMR) magnetic sensor is used.

FIGS. 2A-2Bdepict a pump assembly in accordance with an embodiment of the present invention.FIG. 2Adepicts an outside view of pump assembly106andFIG. 2Bdepicts an inside view of pump assembly106. As can be seen inFIG. 2B, pump assembly106includes head port122of hydraulic cylinder114, rod port124of hydraulic cylinder114, a hose outlet206, a paint piston rod208, a paint pump cavity210, a hydraulic piston rod212, a hydraulic piston214, a paint intake216, a hydraulic cylinder cavity218, a first reed switch220, a second reed switch222, and a magnet224. An actuator (e.g., solenoid valve) directs a hydraulic fluid into hydraulic cylinder cavity218through head port122of hydraulic cylinder114. The hydraulic fluid forces hydraulic piston214to move down through hydraulic cylinder cavity218. As hydraulic piston214moves down through hydraulic cylinder cavity218, paint piston rod208moves down through paint pump cavity210and pushes the paint out hose outlet206. In addition, hydraulic fluid is forced back through rod port124of hydraulic cylinder114, into the solenoid valve and returned to a hydraulic fluid reservoir.

In one example, when hydraulic piston214is at a stroke limit position, magnet224causes first reed switch220to close and complete an electrical circuit (not shown inFIG. 2B). The electrical circuit provides a voltage or other suitable indication that reverses the state of the solenoid valve and causes the hydraulic fluid to flow into hydraulic cylinder cavity218through rod port124of hydraulic cylinder114, thereby reversing the direction of piston214. As piston214travels up, the hydraulic fluid is forced back through head port122of hydraulic cylinder114, into the solenoid valve and returned to the hydraulic fluid reservoir. Paint piston rod208also moves up through paint pump cavity210and draws the paint through paint intake216. When the hydraulic piston has reached its upper stroke limit position, magnet224causes second reed switch222to close, thereby completing an electrical circuit and reversing the hydraulic fluid flow into hydraulic cylinder cavity218through head port122of hydraulic cylinder114.

The integrated software controller may allow for parameter-tracking of performance metrics of pump assembly106. For example, the integrated software controller may comprise a cycle counter configured to track total cycles and run-time over the operational lifetime of assembly106.

FIG. 3depicts an exploded view of a pump assembly in accordance with one embodiment of the present invention. Pump assembly106includes hydraulic cylinder114, paint pump116, and sensor cover assembly304. Sensor cover assembly304can prevent paint from entering the area where the paint piston rod (e.g., paint piston rod208, fromFIG. 2) and hydraulic piston rod212are coupled together and can prevent paint from reaching magnet224and reed switches220and222. In addition, sensor cover assembly304can include first reed switch220, second reed switch222, and a circuit board330.

As shown inFIG. 3, hydraulic cylinder114can include hydraulic cylinder fasteners306, cylinder308, piston head wear ring310, piston head seal312, hydraulic piston214, hydraulic piston rod212, magnet224, hydraulic piston coupler318, piston rod seal324, jam nut332, and a fluid section block334. Hydraulic cylinder fasteners306securely attaches cylinder308to fluid section block334. Cylinder308can include hydraulic cylinder cavity218, fromFIG. 2, head port122of hydraulic cylinder114, fromFIG. 2, and rod port124of hydraulic cylinder114, fromFIG. 2. Piston head wear ring310is a ring that fits into a groove on the outer diameter of hydraulic piston214. Piston head seal312can be a dynamic seal. It can be single acting or double acting and it can be made from nitrile rubber, polyurethane, fluorocarbon viton, etc. Jam nut332can lock the hydraulic piston coupler onto piston rod212and hydraulic piston coupler318can attach hydraulic piston rod212to a paint piston rod (e.g., paint piston rod208, fromFIG. 2).

FIGS. 4A-4Bdepict a cylinder with a limit sensing system in accordance with an embodiment of the present invention.FIG. 4Adepicts a pump assembly400that includes hydraulic cylinder402in a first position with a limit sensing system, consistent with embodiments of the present disclosure. Hydraulic cylinder402can include piston404, piston rod406, head408, base410, head partition412, base partition414, magnet416, first reed switch420, and second reed switch418. The limit sensing system may be coupled to an integrated software controller (not shown inFIG. 4A), in one example, which may serve to detect and control movement of piston rod406, for example by controlling an on/off state of the solenoid valve.

According to various embodiments, as shown inFIG. 4A, piston404is initially located at a stroke limit position, near head408and magnet416causes first reed switch420to change state and complete an electrical circuit (not shown inFIG. 4A). The electrical circuit provides a voltage or other suitable signal to reverse the state of an actuator (e.g., a solenoid valve) and direct hydraulic fluid into cylinder402through head partition412(as shown by arrow422). As the hydraulic fluid flows through head partition412, piston404is forced away from head408. As piston404moves through cylinder402, first reed switch420changes state and the hydraulic fluid is forced back into the actuator through base partition414(as shown by arrow424).

FIG. 4Bdepicts hydraulic cylinder402in a second position with a limit sensing system, consistent with embodiments of the present disclosure. Magnet416is positioned on piston rod406such that when piston404moves through cylinder402and approaches base410, magnet416approaches second reed switch418and causes second reed switch418to change state. This will complete an electrical circuit and provide a voltage or other suitable signal to reverse the state of the solenoid valve and thus, reverse the flow of the hydraulic fluid and move piston404away from base410. In one example, information about an operation loop is collected by an integrated software controller (not shown inFIG. 4B). Parameter tracking, such as cycle counters and run-time tracking may allow for evaluation of the performance of assembly400over time. Additionally, an integrated software controller may allow for determination of a piston location within an operational loop prior to pump start-up.

FIGS. 5A-5Bdepict exploded and assembled views of a planetary roller screw drive in accordance with an embodiment of the present invention.FIG. 5Adepicts an exploded view of a planetary roller screw drive600andFIG. 5Bdepicts an assembled view of the planetary roller screw drive600, consistent with embodiments of the present disclosure. Planetary roller screw drive600includes rod602, cog604, rollers606, roller retainer608, and tube610. According to various embodiments, planetary roller screw drive600can be used in place of, or in combination with, a hydraulic cylinder (e.g., hydraulic cylinder400). Planetary roller screw drive600is a mechanical device for converting rotational motion to linear motion.

According to various embodiments, threaded rod602provides a helical raceway or thread612for multiple rollers606radially arrayed around rod602and encapsulated by threaded tube610. The lead for thread612is the axial travel for a single revolution. The pitch of thread612is defined as the axial distance between adjacent threads of thread612. Thread612of rod602typically has the same pitch or corresponding features to the internal thread of tube610. Rollers606spin in contact with, and serve as transmission elements between rod602and tube610. Rollers606typically have a single-start thread where a single helical thread is along their length and the lead and pitch are equal. This can limit the friction as rollers606contact rod602and tube610. Rollers606orbit rod602as they spin and rotation of tube610results in rod602travel, and rotation of rod602results in tube610travel.

FIGS. 6A-6Bdepict a planetary roller screw drive with a limit sensing system in accordance with an embodiment of the present invention.FIG. 6Adepicts a planetary roller screw drive700in a first position with a limit sensing system, consistent with embodiments of the present disclosure. Planetary roller screw drive700can include a rod702, rollers704, tube706, head708, base710, magnet712, first reed switch714, and second reed switch716.

According to various embodiments, as shown inFIG. 6A, rod702is initially located at a stroke limit position, near head708and magnet712causes first reed switch714to change state and complete an electrical circuit (not shown inFIG. 6A). In one example, an electrical circuit provides a voltage or other suitable signal to reverse the rotation of rollers704and move rod702away from head708. As rod702moves through tube706, first reed switch714changes state. In another example, control of the solenoid valve-is provided by an integrated software controller (not shown inFIG. 6A). The integrated software controller may be configured to detect the presence of magnet712, in one embodiment, using reed switches714and716.

FIG. 6Bdepicts planetary roller screw drive700in a second position with a limit sensing system, consistent with embodiments of the present disclosure. Magnet712is positioned on rod702such that when rod702moves through tube706and approaches base710, magnet712approaches second reed switch716and causes second reed switch716to change state. This will complete an electrical circuit and provide a voltage or other suitable signal to reverse the rotation of rollers704and move rod702away from base710.

FIG. 7depicts a hydraulic circuit in accordance with an embodiment of the present invention. In various embodiments, hydraulic circuit500can include a hydraulic reservoir502, a hydraulic pump504, a solenoid506, a head port508, a rod port510, a hydraulic cylinder512, a paint cylinder514, a paint reservoir516, and a spray gun518. In certain embodiments, hydraulic pump504can pump hydraulic fluid from hydraulic reservoir502to solenoid506. InFIG. 7, solenoid506is illustrated as a directional control valve. Directional control valves can allow fluid to flow into different paths from one or more sources. They can consist of a spool inside a cylinder and can be mechanically, electrically, and hydraulically controlled. Moreover, the movement of the spool can restrict or permit the flow of the hydraulic fluid from hydraulic reservoir502.

In this embodiment, an electromechanical solenoid is used to operate a 4-way, 2 position valve since there are 2 spool positions and 4 valve ports. However, other position valves can be used. The 4-way, 2 position valve combined with the reed switch sensor (not shown inFIG. 7) enables fast switching between the down stroke and the up stroke of hydraulic cylinder512. This allows hydraulic circuit500to achieve a consistent paint pressure. In this example, initially, head port508is the pressure port which is connected to hydraulic pump504and the rod port is connected to hydraulic reservoir502. As the hydraulic fluid is directed into head port508the pressure inside hydraulic cylinder512forces the hydraulic piston to move down through hydraulic cylinder512and the hydraulic fluid is pushed out rod port510and back to hydraulic reservoir502. Since hydraulic piston is attached to the paint piston, the paint piston also moves down through paint cylinder514and paint, located in the paint cylinder, is pushed into spray gun518.

In one example, when the hydraulic piston has reached a stroke limit position, the reed switch sensor can provide a voltage that activates a set of MOSFETs and flip-flop integrated circuit (not shown inFIG. 7), causing solenoid506to slide the spool to its second position. As a result, rod port510is the pressure port which is connected to hydraulic pump504and the head port is connected to hydraulic reservoir502. As the hydraulic fluid is directed into rod port510the pressure inside hydraulic cylinder512forces the hydraulic piston to move up through hydraulic cylinder512and the hydraulic fluid is pushed out the head port and back to hydraulic reservoir502. Moreover, the paint piston also moves up through paint cylinder514and paint from paint reservoir516can be drawn up into paint cylinder516.

In another example, solenoid506is controlled by an integrated software controller (not shown inFIG. 7), communicably coupled to solenoid506. An integrated software controller may be useful to locate a position of the piston is detectable prior to start-up of the pump assembly.

FIG. 8depicts a system diagram for a liquid dispensing system in accordance with an embodiment of the present invention. Fluid dispensing system800may be useful, for example, for dispensing paint, or other exemplary fluids such as primers, coatings, plural components, etc. System800may comprise a fluid source810operably coupled to a pump820within fluid dispensing system800. Pump820may comprise, for example, a planetary roller screw pump such as that presented inFIGS. 5A and 5B, or a hydraulic pump such as that presented inFIG. 3. Pump820is operably coupled to a pump controller830. Pump820may be configured to pressurize, or otherwise deliver fluid from fluid source810to an outlet802. Controller830may be configured, in one example, to provide an output804. In one example, output804comprises storing detected parameters concerning operation of pump820in a memory of controller830. In another example, output804comprises delivery of detected parameters to a separate unit, for example downloading detected parameter information to a separate computing unit. In another example, output804comprises an audio or visual output, for example an audible alert or a visual indication, such as a separate display unit. Fluid dispensing system800, in some embodiments, comprises other features840integral to the delivery of fluid from fluid source810to outlet802. For example, in an embodiment where a fluid is delivered at a set temperature, other functionality840comprises a heater. Additionally, in some embodiments, fluid may be transferred a significant distance from pump820to outlet802. Other functionality840may comprise a transport mechanism in such embodiments.

FIG. 9depicts a diagram of a pump system control in accordance with an embodiment of the present invention. Pump910of pump system900may, in one example, comprise a planetary roller screw pump system such as that presented inFIGS. 5A and 5B. In another example, pump910comprises a hydraulic pump system, such as that presented inFIG. 3. However, pump system900may also be useful with other exemplary pump configurations.

Pump910comprises, in one example, a fluid section piston912coupled to a hydraulic piston914. Movement of hydraulic piston914is limited, in one example, by one or more switching mechanisms918. Switching mechanisms918may comprise reed switches, for example. However, other switching mechanisms918may also be used. For example, an integrated software controller920may be configured to control a solenoid. Pump910may also include one or more limit sensors916. Pump910may also comprise other components928.

Controller920, in one example, is configured to operably control and monitor pump910. Controller920, in one embodiment, comprises a detector922configured to detect a position of fluid section piston912prior to operation of pump910. Detector922may receive a signal from limit sensor916, for example, indicating a position of fluid section piston912within an operational loop. For example, fluid section piston912may be mid-stroke, topped out, bottomed out, or in another position within an operational loop. Knowing a detected position of fluid section piston912within an operational loop may allow for controller920to resume a normal operational loop of fluid section piston912based on its detected current position. Controller920may also comprise other functionality924.

During a normal operational cycle, controller920, in one embodiment, is responsible for controlling movement of fluid section piston912within a cylinder. For example, as fluid section piston912moves toward an end of a stroke, limit sensor916can send an indication, to detector922, causing the controller to switch the direction of piston movement, for example using switching mechanism918. Switching mechanism918can comprise, for example, a reed switch, in one embodiment. Alternatively, in one embodiment, switching mechanism918comprises a solenoid coupled to the controller. In another embodiment, switching mechanism918comprises a solenoid coupled to a MOSFET and a flip-flop integrated circuit system.

Limit sensor916can comprise, in one embodiment, a hall-effect sensor. In another embodiment, limit sensor916comprises a photoelectric sensor. In another embodiment, limit sensor916comprises a mechanical sensor. In another embodiment, limit sensor916comprises a base active transducer sensor. In another embodiment, limit sensor916comprises an eddy-current sensor. In another embodiment, limit sensor916comprises an inductive position sensor. In another embodiment, limit sensor916comprises a photodiode array sensor. In another embodiment, limit sensor916comprises a proximity sensor. However, other suitable limit sensors916are also envisioned. For example, in one embodiment, limit sensor916comprises an anisotropic magneto-resistive (AMR). In another embodiment, limit sensor916comprises a giant magneto-resistive (GRM) magnetic sensor.

Controller920may be coupled, in one example, to a memory930. Memory930is illustratively shown as part of pump system900. However, in another example, at least some portions of memory930are stored remotely from pump system900. For example, a start-up sequence932may be stored within an integrated memory coupled to controller920such that controller920can retrieve sequence932and engage pump910. However, historic data936may only be accessible when integrated controller920is coupled to a remote computing system950, where current operational information938may be downloaded and compared to historic data936to track operational parameters related to operation of pump910over time. Memory930may also store a counter934. Counter934may be responsible for tracking a total cycle count of pump910, a live cycle-rate counter, and/or track a run time of pump910for a given operation. Memory930may also comprise other functionality942.

Pump system900may also illustratively comprise a user interface940. User interface940may allow an operator to interact with controller920. User interface940may comprise an input/output mechanism, such as a set of buttons, keys, etc. User interface940may comprise a display attached to pump system900. User interface940, in another example, may comprise a display on a separate computing unit950, such that interaction with controller920and memory930is limited to a configuration where controller920is communicably coupled with separate computing unit950, for example during or after a download of operational information938from memory930. Pump system900may also comprise other functionality960, for example a heating mechanism to heat a fluid prior to delivery to an outlet, or a transport mechanism configured to transport pressurized fluid to an outlet.

FIG. 10depicts a flow diagram of a method for start-up of a pump control system in accordance with an embodiment of the present invention. In one example, a system controller, such as controller920, retrieves a start-up sequence, such as sequence932, from an integrated memory930. Start-up sequence932may, for example, provide instructions for implementing method1000.

In block1010, a pump system is engaged. Engaging the pump system may comprise turning on an associated motor, initiating priming operations, and/or other appropriate start-up operations.

In block1020, a piston position is located. For example, as a result of a previously completed operation, a piston may be detected as mid-stroke, as indicated in block1022, topped out, as indicated in block1024, bottomed out, as indicated in block1026, or in another position, as indicated in block1028. A controller, knowing the location of a piston, may be able to start a normal operational loop from the present location, instead of having to estimate a position.

In block1030, an operational loop is started. The operational loop may be initiated, in part, based on a detected location of the piston, in one example. Starting the operational loop in block1030may also comprise a controller retrieving and initiating one or more parameter tracking sequences. For example, the controller can retrieve and initiate a cycle counter, as indicated in block1032. A cycle counter may comprise a live operational cycle counter, for example starting at ‘0 cycles.’ In another example, a cycle counter may comprise a lifetime cycle counter for a pump system, such that a controller retrieves a total cycle count, for example, comprising a cycle count at the end of a previous operation, and continue counting through a present operation, providing an ending cycle counter for the beginning of the next operation. Starting an operational loop, in block1030, may also comprise the controller retrieving a runtime tracking sequence and starting a runtime counter, as indicated in block1034, which may provide an ongoing indication of how long a current operation has been ongoing. Starting an operational loop may also comprise starting other parameter tracking sequences, as indicated in block1036.

In block1040, in some embodiments, data regarding an operation is stored. For example, runtime counter information, cycle counter information, or other parameter data can be tracked and stored for a given operation. Such data may also be accumulated and stored over time, for example to provide diagnostic information. Data can be stored, in one embodiment, in an onboard memory associated with the pump control system, as indicated in block1042. Data can also be stored, in one embodiment, in a remote memory component, as indicated in block1044, for example associated with a separate computing unit. Data can also be stored in other configurations, as indicated in block1046.