阅读说明：本技术 检测由螺线管线性致动器驱动的阀门位置的系统和方法 (System and method for detecting valve position driven by solenoid linear actuator ) 是由 亚伦·赫泽尔·贾戈达 于 2019-07-05 设计创作，主要内容包括：本发明题为“检测由螺线管线性致动器驱动的阀门位置的系统和方法”。本发明公开了一种阀门组件,所述阀门组件包括可在允许液压流体流动的打开位置与阻止液压流体流动的闭合位置之间移动的阀门。控制器包括磁力仪,所述磁力仪适于测量通过移动所述阀门的螺线管线性致动器的至少一部分的磁通量。由所述磁力仪测量的磁通量值对应于所述调节构件相对于所述端口的线性位置。(The invention provides a system and method for detecting valve position driven by a solenoid linear actuator. A valve assembly is disclosed that includes a valve movable between an open position to allow hydraulic fluid flow and a closed position to prevent hydraulic fluid flow. The controller includes a magnetometer adapted to measure a magnetic flux through at least a portion of a solenoid linear actuator that moves the valve. The magnetic flux value measured by the magnetometer corresponds to a linear position of the adjustment member relative to the port.)

1. A valve assembly, comprising:

an adjustment member mounted within an aperture of a valve housing, the adjustment member being movable between a plurality of open positions allowing fluid flow through a port of the valve housing and a closed position preventing fluid flow through the port;

a solenoid linear actuator adapted to linearly drive the adjustment member between the closed position and the plurality of open positions; and

a magnetometer adapted to measure magnetic flux passing through at least a portion of the solenoidal actuator,

wherein the magnetic flux value measured by the magnetometer corresponds to a linear position of the adjustment member relative to the port.

2. The valve assembly of claim 1, wherein the regulating member is one of a flow regulating member or a pressure regulating member.

3. The valve assembly of claim 1, further comprising an ammeter to measure current in the solenoidal actuator, wherein a value of current in the solenoidal actuator measured by the ammeter is mapped to a desired magnetic flux value measured by the magnetometer.

4. The valve assembly of claim 3, wherein the current value is further mapped to a desired inductance value in the solenoid linear actuator.

5. The valve assembly of claim 1, wherein a lookup table is generated and stored in memory that maps each of a plurality of current values in the solenoid linear actuator to a corresponding desired magnetic flux value or a corresponding pair of magnetic flux inductances, wherein the magnetic flux values or pairs of magnetic flux inductances correspond to unique linear positions of the regulating member relative to the port.

6. The valve assembly of claim 5, wherein for a given current value provided to the solenoid, the magnetic flux or pair of flux inductances is measured and used as feedback that is compared to the stored expected magnetic flux value or the expected pair of flux inductances corresponding to the given current value to determine whether to perform a corrective action.

7. The valve assembly of claim 6, wherein the corrective action comprises regulating current in the solenoid.

8. The valve assembly of claim 7, wherein the corrective action comprises shutting down a system that includes the valve assembly.

9. The valve assembly of claim 1, wherein the fluid flowing through the port is a liquid or a gas when the regulating member is in one of the open positions.

10. The valve assembly of claim 1, wherein the regulating member is a spool or poppet valve.

11. The valve assembly of claim 1, wherein the regulating member is a base of a valve cartridge.

12. The valve assembly of claim 1, wherein the magnetometer is an integrated component of a control unit that controls metered flow through the port.

13. The valve assembly of claim 1, wherein the magnetometer is adapted to measure a magnetic flux vector relative to each of three mutually perpendicular axes in space.

14. The valve assembly of claim 12, wherein the control unit comprises a printed circuit board operatively coupled to the magnetometer, gyroscope, and accelerometer.

15. The valve assembly of claim 1, wherein the magnetometer is not positioned in the flow channel of the valve assembly or a system comprising the valve assembly.

16. The valve assembly of claim 12, wherein the control unit is not positioned in a flow path of the valve assembly or a system comprising the valve assembly, and/or wherein the control unit is not exposed to hydraulic pressure.

17. A method of detecting a deviation from a desired position of an adjustment member of a valve assembly in a mechanical system, comprising:

measuring a first magnetic flux value through a solenoid of the valve assembly with a magnetometer for a first current value received by the solenoid that drives linear movement of the regulating member;

comparing the first magnetic flux value to a predetermined desired magnetic flux value corresponding to the first current value; and the number of the first and second groups,

based on the comparison, it is determined whether there is a deviation from the desired position of the adjustment member.

18. The method of claim 17, further comprising: measuring a first inductance value in the solenoid for the first current value received by the solenoid; and comparing the first inductance value to a predetermined desired inductance value corresponding to the first current value, wherein the determining whether there is a deviation is also based on the comparing the first inductance value to the predetermined desired inductance value.

19. The method of claim 17, further comprising adjusting the current received by the solenoid until the desired magnetic flux value is measured by the magnetometer.

20. The method of claim 18, further comprising adjusting the current received by the solenoid until the desired inductance value is measured.

21. The method of claim 17, wherein the desired magnetic flux value is one of a plurality of desired magnetic flux values and the first current value is one of a plurality of current values, wherein the method further comprises generating a lookup table that maps each of the current values to one of the desired magnetic flux values.

22. The method of claim 21, wherein the desired inductance value is one of a plurality of desired inductance values, wherein the generating a look-up table comprises mapping each of the current values to one of the desired magnetic flux values and one of the desired inductance values.

23. The method of claim 17, wherein the fluid is a liquid.

24. The method of claim 17, wherein the fluid is a gas.

25. The method of claim 17, wherein the adjustment member is a metering substrate of a valve cartridge.

26. The method of claim 17, wherein the magnetometer is an integrated component of a control unit that controls metered flow through the port.

27. The method of claim 17, wherein the magnetometer is adapted to measure a magnetic flux vector relative to each of three mutually perpendicular axes in space.

Background

Many mechanical systems, such as hydraulic systems, include valves that regulate the flow of fluid. In the case of hydraulic systems, valves are used to regulate the flow of hydraulic fluid. The valve includes a flow or pressure regulating member that moves relative to a port in the fluid flow passage to regulate fluid flow. Some hydraulic systems include spool or poppet-type valves, where the adjustment member is one or more substrates of the spool or poppet that move within the flow passage. In some systems, the adjustment member is driven by a solenoid linear actuator. Knowledge of the position of the adjustment member relative to its corresponding port or ports is important for controlling the overall system as needed and for detecting mechanical problems or faults in the system. In a typical hydraulic spool valve assembly, spool position is detected using a Linear Variable Differential Transformer (LVDT) coupled directly to the spool. LVDTs, however, are expensive and can be damaged over time by exposure to high pressure hydraulic fluid in the flow channels in which they are located.

Disclosure of Invention

Generally, the present disclosure relates to systems and methods that provide cost-effective and/or otherwise improved valve assemblies. More specifically, the systems and methods of the present disclosure provide improvements in detecting the position of a flow regulating member or a pressure regulating member of a valve driven by a solenoid linear actuator. In some examples, the detected position of the adjustment member may be used to diagnose a possible fault in the system that may require maintenance. In other examples, the detected position may be used as an indicator that the current to the solenoid must be increased or decreased to achieve the desired position of the flow control member or the pressure control member. In some embodiments, the valve assembly is a hydraulic valve assembly that regulates the flow or pressure of hydraulic fluid. However, the principles of the present disclosure are not limited to hydraulic valves or hydraulic systems; rather, these principles may be readily applied to any valve assembly and corresponding system in which the flow or pressure control member of the valve is driven by a solenoid linear actuator or another type of electromagnetically driven linear actuator. Non-limiting examples of hydraulic systems that may be adapted to include a valve assembly and controller according to the principles of the present disclosure include asphalt sprayers, backhoe loaders, wheel loaders, tractors, telescopic boom forklift trucks, aerial work platforms, and the like.

According to certain aspects of the present disclosure, a valve assembly comprises: a regulating member mounted within the bore of the valve housing, the regulating member being movable between a plurality of open positions in which fluid flow is permitted through a port of the valve housing and a closed position in which fluid flow is prevented through the port, the valve assembly further comprising a solenoid linear actuator adapted to linearly drive the regulating member between the closed position and the plurality of open positions; the valve assembly further comprises a magnetometer adapted to measure magnetic flux through at least a portion of the solenoid linear actuator; wherein the magnetic flux value measured by the magnetometer corresponds to the linear position of the adjustment member relative to the port.

In some examples, the regulation member is one or both of a flow regulation member or a pressure regulation member. In some examples, the valve assembly further comprises a current meter measuring current in the solenoid linear actuator, wherein a value of the current in the solenoid linear actuator measured by the current meter is mapped in the look-up table to a desired magnetic flux value measured by the magnetometer. In some examples, the current values are mapped to desired magnetic flux values and desired inductance values in the solenoid coil, or to desired magnetic flux-inductance pair values. In some examples, a lookup table is generated and stored in memory that maps each of a plurality of current values in the solenoid linear actuator to its corresponding desired magnetic flux value or pair of magnetic flux inductances, where the magnetic flux value or pair of magnetic flux inductances corresponds to a unique linear position of the adjustment member relative to the port. In some examples, during operation of the valve assembly, for a given current value provided to the solenoid, a magnetic flux or pair of flux inductances is measured and used as feedback that is compared to a stored desired magnetic flux value or a desired pair of flux inductances corresponding to the given current value to determine whether to perform a corrective action that includes adjusting the current in the solenoid until a magnetic flux or combination of magnetic flux and inductance corresponding to a desired position of the adjustment member is reached and/or shutting down the system including the valve assembly. In some examples, the fluid flowing through the port is a liquid when the adjustment member is in one of the open positions. In some examples, the fluid flowing through the port is a gas when the regulating member is in one of the open positions. In some examples, the adjustment member is a spool. In some examples, the adjustment member is a metering base of the valve cartridge. In some examples, the adjustment member is a poppet of a poppet valve assembly. In some examples, the magnetometer is an integrated component of the control unit that controls the metered flow through the port. In some examples, the magnetometer is adapted to measure a magnetic flux vector relative to each of three mutually perpendicular axes in space. In some examples, the control unit includes a printed circuit board operatively coupled to the magnetometer, the gyroscope, and the accelerometer. In some examples, the magnetometer is not positioned in the flow channel of a valve assembly or a system comprising a valve assembly. In some examples, the control unit is not positioned in a flow passage of a valve assembly or a system including a valve assembly. In some examples, the control unit includes a memory and/or one or more processors operatively coupled to the memory and adapted to execute computer-readable instructions stored in the memory. In some examples, the control unit is operatively coupled to an operator interface adapted to receive commands to control the position of the adjustment member. In some examples, the control unit corresponds to any of the control units and/or controllers described in U.S. provisional patent application No. 62/692,173 filed on day 29 of 2018, U.S. provisional patent application No. 62/692,120 filed on day 29 of 2018, U.S. provisional patent application No. 62/692,072 filed on day 29 of 2018 and/or U.S. provisional patent application No. 62/691,975 filed on day 29 of 2018, the contents of all of which are incorporated herein by reference in their entirety.

According to other aspects of the present disclosure, a method of detecting a deviation in a desired position of an adjustment member of a valve assembly in a mechanical system includes: measuring a first magnetic flux value through a solenoid of a valve assembly with a magnetometer for a first current value received by the solenoid to drive linear movement of a regulating member; comparing the first magnetic flux value to a predetermined desired magnetic flux value corresponding to the first current value; and determining whether there is a deviation from the desired position of the adjustment member based on the comparison.

In some examples, the method further comprises: measuring a first inductance value in the solenoid for a first current value received by the solenoid; and comparing the first inductance value to a predetermined desired inductance value corresponding to the first current value, wherein determining whether there is a deviation is also based on comparing the first inductance value to the predetermined desired inductance value. In some examples, the method further includes adjusting the current received by the solenoid until a desired magnetic flux value is measured by the magnetometer. In some examples, the method further includes adjusting the current received by the solenoid until a desired inductance value is measured. In some examples, the desired magnetic flux value is one of a plurality of desired magnetic flux values and the first current value is one of a plurality of current values, wherein the method further comprises generating a lookup table that maps each of the current values to one of the desired magnetic flux values. In some examples, the desired inductance value is one of a plurality of desired inductance values, wherein generating the look-up table includes mapping each of the current values to one of the desired magnetic flux values and one of the desired inductance values. In some examples, the fluid is a liquid. In some examples, the fluid is a gas. In some examples, the adjustment member is a metering base of the valve cartridge or the valve cartridge. In some examples, the magnetometer is an integrated component of the control unit that controls the metered flow through the port. In some examples, the magnetometer is adapted to measure a magnetic flux vector relative to each of three mutually perpendicular axes in space.

Drawings

FIG. 1 is a schematic view of an example system including a valve assembly according to the present disclosure.

Fig. 2 is a schematic diagram of a look-up table used in the system of fig. 1.

FIG. 3 depicts a proportional valve equipped with a control module according to the principles of the present disclosure.

Fig. 4 is a flowchart illustrating an operation sequence for determining whether the position of the spool deviates from the desired position.

FIG. 5 is a schematic diagram of a hydraulic system for powering hydraulic actuators of an excavator.

FIG. 6 depicts another proportional valve equipped with a control module according to the principles of the present disclosure.

Detailed Description

Various embodiments will be described in detail with reference to the accompanying drawings. Reference to various embodiments does not limit the scope of the claims appended hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims.

An operator controls the flow of a valve or the position of a pressure regulating member within a mechanical system by issuing various operating commands to the system (e.g., via a joystick or other command interface). As valves deteriorate or wear, the position of the flow or pressure regulating members of these valves may deviate from the position desired for a given operating command, resulting in, for example, too much or too little flow, undesirable pressure differentials across the valves, and the like. It is therefore advantageous to detect such deviations during system operation so that command inputs can be adjusted to achieve a desired flow/pressure and also to prevent system failures and their consequences, such as machine/equipment failures.

FIG. 1 illustrates a machine system 10 that is operated, at least in part, through the use of hydraulics. The hydraulic device includes a non-limiting embodiment of a valve assembly 100 used to illustrate the principles of the present invention. In some examples, the valve assembly is a flow metering valve. The valve assembly 100 includes a housing 103 that houses a spool 112 mounted in a spool bore 114 defined by the housing 103. In this example, the spool valve is a three-way spool valve. However, the principles of the present disclosure are readily applicable to other spool valves (e.g., two-way spool valves) and other flow control valves, such as poppet valves. Spool 112 includes a shaft 126 coupled to a pair of metering substrates 122 and 124 on either end of shaft 126, each of which is a regulating member (e.g., a fluid flow and/or fluid pressure regulating member) of valve assembly 100. A solenoid linear actuator 130 (solenoid) is coupled to the valve spool 112 and is adapted to drive axial linear movement of the valve spool 112 within the bore 114 along the central axis a of the bore 114.

A fluid supply 101 (e.g., a pump) supplies hydraulic fluid to a workport 104 through a supply port 105 via a supply line 102. The workport 104 is connected to a hydraulic cylinder 106 that drives a load, such as a load of a piece of hydraulic equipment or machinery. Fluid from the workport 104 empties into the tank 108 via the tank port 107 and the tank line 110.

In some examples, the system 10 maintains a constant or controlled pressure differential across the valve. In other examples, the position of the spool 112 in combination with the sensed differential pressure may be used to estimate the fluid flow rate through the port.

The control unit 170 is operably and fixedly mechanically coupled to the solenoid 130 and is configured to provide a control signal that generates an electrical current in the solenoid 130 to drive the axial linear movement of the adjustment members 122 and 124 along axis a. The control unit 170 is in a fixed position relative to the coil or coils 132 of the solenoid 130. The control unit 170 is located outside of the bore 114 and any hydraulic flow passages and is therefore not exposed to hydraulic pressure generated by the system 10.

The control unit 170 includes a PCB or other circuitry having a magnetometer 172 operatively coupled thereto. The PCB also includes control electronics, and optionally an accelerometer and/or gyroscope. Due to the fixed mechanical coupling of the solenoid 130 with the control unit 170, there is a fixed or substantially fixed distance between the magnetometer 172 and the coil or coils 132 of the solenoid 130. In some examples, the magnetometer 172 is adapted to measure magnetic flux vectors along three mutually perpendicular axes.

The control unit 170 further comprises a current meter 173, e.g. an electricity meter, adapted to measure the current in the coil or coils 132 of the solenoid 130. The inductance sensor 175 may be included in the control unit 170 or optionally located remotely from the control unit 170, adapted to measure the inductance in the coil or coils 132 of the solenoid 130. In some implementations, the inductance is sensed by applying a dither signal to the current (which is applied to the solenoid 130) and monitoring the range of change in the current. In one example, the dither signal is applied when the spool 112 is held in a given position. In one example, a small amplitude square wave is applied at the steady state current value, and the inductance is determined by looking at the rate of rise or decay as the measured current approaches the command current.

The measurements from current meter 173, inductive sensor 175 and magnetometer 172 are fed to an operating subsystem 174 of system 10, which operating subsystem 174 is operatively coupled to control unit 170. The operational subsystem 174 includes one or more processors 180 that are adapted to execute computer-readable instructions and process signals received from the control unit 170. The operational subsystem 174 also includes memory 178 and a command interface 176, both of which are operatively coupled to one or more processors 180. In addition to storing computer readable instructions, the memory 178 also stores a look-up table 200.

When the solenoid 130 receives current to drive axial linear movement of the spool 112 along the axis a relative to the supply port 105, a portion 113 of the spool 112, or a portion of the spool assembly including the spool 112, and fixedly coupled to the spool 112 moves relative to the coil or coils 132 of the solenoid 130 such that the magnetic flux through the coil or coils 132 changes, which also generates inductance in the coil or coils 132.

These different magnetic fluxes are determined in part by the position of the spool 112 or spool assembly relative to the supply port 105 as a three-dimensional vector measured by the magnetometer 172 when the system 10 is initialized and calibrated. These different magnetic fluxes are also mapped to current values read by the current meter 173, which correspond to the amount of current the solenoid 130 is charged to cause the spool 112 to occupy a position corresponding to the measured magnetic flux, thereby providing an index of the expected magnetic flux values for the different currents received by the solenoid 130.

Once the lookup table 200 is filled with all desired magnetic flux values and corresponding current values, the lookup table 200 may be used as a system operating baseline to check for deviations from the desired magnetic flux values when operating commands corresponding to a given current received by the solenoid 130 are input. A deviation or a deviation beyond a predefined tolerance indicates that the spool 112 is not in the desired position, i.e., is not in the desired position for a given operating command.

Referring to fig. 2, the look-up table 200 includes a column of current values 204 having current values 210 that are mapped to corresponding desired flux values 208 of the desired flux column 202. Each desired magnetic flux value 208 corresponds to a desired linear position of the regulating member 112 (fig. 1) of the valve assembly relative to the supply port 105 (fig. 1) when the solenoid 130 (fig. 1) receives a corresponding current value 210.

Referring to fig. 1-2, in some examples, the lookup table 200 maps not only the current values 210 to corresponding desired magnetic flux values 208, but also to corresponding desired inductance values or desired magnetic flux-inductance pair values, where the inductance in the solenoid 130 is measured by the inductance sensor 175. The combined information provided by the inductance and the magnetic flux is indicative of the linear position of the spool 112 relative to the supply port 105. It should be appreciated that, in some examples, comparing the measured magnetic flux and the measured inductance to both the expected magnetic flux and the expected inductance, respectively, may provide greater accuracy to determine the linear position of the spool 112 relative to the supply port 105 for a given current received by the solenoid 130 than simply comparing the measured magnetic flux to the expected magnetic flux.

Still referring to fig. 1-2, in the example sequence of operation of the system 10, once the look-up table 200 has been completely filled, a command is input via the command interface 176 to drive the spool 112 to move linearly along the axis a via the solenoid 130. The signal corresponding to the command is processed by the processor 180 and output to the control unit 170, which charges the solenoid 130 with a known current corresponding to the command. The energized solenoid 130 moves the spool 112 along axis a. The magnetic flux feedback from the magnetometer 172 or the magnetic flux feedback from the magnetometer 172 and the inductive feedback from the inductive sensor 175 are compared using the processor 180 to a desired magnetic flux value or a desired magnetic flux and inductance value for a known current provided in the look-up table 200. The processor 180 thus determines whether the position of the spool 112 deviates from the desired position corresponding to the input command. If the sensed and expected values match or match within a predefined tolerance, a deviation between the expected position of the spool 112 and the measured position of the spool 112 is detected. If the sensed and expected values do not match or do not match within a predefined tolerance, a deviation between the expected position and the measured position is detected and, optionally, one or more corrective actions occur. Such corrective actions include, for example, automatically adjusting or prompting an operator to adjust the current received by the solenoid 130 via the interface 176, providing a possible system fault alert via the interface 176, automatically shutting down, or prompting an operator to shut down the system 10 via the interface 176, etc.

Feedback from the magnetometers 172 and/or the inductive sensors 175 can be continuous or repeated at predefined intervals or at predefined times (e.g., each time a different value of command input is received) during operation of the system 10 to provide effective real-time diagnostics, monitoring, and corrective action if desired.

Fig. 3 depicts one example implementation of a valve assembly 100 in the form of a proportional spool valve 300 equipped with an electronic control unit 302 according to the principles of the present disclosure. The valve 300 includes a valve body 304 adapted to be mounted (e.g., threaded) in a port (e.g., valve manifold) of a valve block. A spool 306 is mounted for axial movement within a spool bore 308 defined by the valve body 304. By axially moving the spool 306 between different axial positions within the spool bore 308, fluid communication may be selectively opened and closed between the various ports 310 a-310 d defined by the valve body 304. The valve 300 includes a solenoid 312 for controlling axial movement of the valve spool 306. The solenoid 312 includes an armature 314 positioned within a solenoid coil 316. The armature 314 moves axially a distance proportional to the magnitude of the current through the solenoid coil 316. Thus, the position of the armature 314 may be changed by changing the current through the solenoid coil 316. The armature 314 is operatively coupled to the bobbin 306 such that the bobbin 306 moves axially with the armature 314. The size of the valve flow passage defined between the ports, and thus the flow rate through the valve between the ports, varies with the position of the valve spool 306, which is controlled by the magnitude of the current directed through the solenoid coil 316.

The control unit 302 is electrically connected to the solenoid coil 316 (e.g., via a dual-contact electrical connector) and is adapted to direct electrical current to the coil 316 to control operation of the valve 300. In response to control commands input to the central controller 315 by an operator via the control interface 317, the control unit 302 can vary the magnitude of the current provided to the coil 316.

The electronic control unit 302 includes a module housing 303 containing a structure such as a magnetometer 307 (e.g., a three-axis magnetometer) and a current meter 309 operably connected thereto. In some implementations, the electronic control unit 302 also includes an inductive sensor 301. The control unit 302 is mounted at a position where the magnetometer 307 may have the magnetic flux of the solenoid coil 316. For example, the control unit 302 may be mounted to the solenoid 312 (e.g., to a solenoid housing) or elsewhere, such as on a valve manifold (e.g., a valve block). In one example, the control unit 302 is mechanically and electrically connected to the solenoid coil 316 by an electrical connector, such as a two-contact (e.g., 2-pin) connector, that is received within a receptacle corresponding to the solenoid coil 316. Due to the fixed mechanical coupling of the solenoid 312 with the module housing 303, there is a fixed or substantially fixed distance between the magnetometer 307 and the coil or coils 316 of the solenoid 312.

In some implementations, the electronic control unit 302 includes electronic circuitry that couples the sensors 301, 307, 309 to one or more control processors and memory accessible by the one or more control processors. In the example shown, a control processor 305 and memory 311 are provided within the module housing 303 to directly control the sensors 301, 307, 309. In some implementations, the electronic control units 302 may be integrated as part of a system that implements a communication protocol, such as a controller area network bus (CAN bus), for coordinating the operation of the plurality of electronic control units 302. The control unit 302 may be electrically connected to the central controller 315 by wires 313 (which may comprise a wire bundle, for example). In this way, electrical power and supervisory control may be provided to the control unit 302. A control interface 317 (e.g., a joystick, dial, toggle, or other device for allowing an operator to input control commands to the central controller 315) is connected to the central controller 315. Alternatively, the sensors 301, 307, 309 may be controlled directly by the central controller 315.

The control processor 305 and/or the central controller 315 may be adapted to execute computer readable instructions (e.g., instructions stored on the memory 311) that allow the electronic control unit 302 to monitor the flux feedback from the magnetometer 307, or both the flux feedback from the magnetometer 307 and the inductive feedback from the inductive sensor 301, and send the measurements to the central controller 315. The control processor 305 and/or the central controller 315 may also be adapted to measure the current in the coil or coils 316 of the solenoid 312 and send the measurements to the central controller 315.

Fig. 4 is a flow chart illustrating an example sequence of operations 400 for a system including the valve assembly 300 and the control unit 302. The operational sequence 400 begins at a calibration step 402, where current values are mapped to magnetic flux values for a given spool 306 and solenoid 312. In some examples, these mapping values are stored in a database (e.g., lookup table 200 of fig. 2). For example, for each or a portion of the current value applied to the solenoid 312 during calibration, the amount of magnetic flux due is measured.

In a receive command step 404, a command to move the spool 306 is received from a user. For example, the instructions may be provided by a user via control interface 317. In some examples, the command indicates a direction to move the spool 306. In some examples, the command indicates the distance to move the spool 306 or the position to which the spool 306 will move. The control processor 305 and/or the central controller 315 determines the amount of current that needs to be applied to the solenoid 312 to move the spool 306 according to the received commands. The control unit 302 applies a determined amount of current to the solenoid 312 in an application step 406.

In an obtaining step 408, the control processor 305 and/or the central controller 315 accesses a memory (e.g., memory 311) to obtain a desired magnetic flux feedback for the determined current value applied to the solenoid 312. In certain implementations, the control processor 305 and/or the central controller 315 accesses a lookup table, such as the lookup table 200 of fig. 2, to obtain the magnetic flux values that map to the values of the determined amount of current. In certain implementations of the obtaining step 408, the control processor 305 and/or the central controller 315 access a memory (e.g., memory 311) to also obtain the desired inductive flux feedback for the determined current value. In certain implementations, the control processor 305 and/or the central controller 315 accesses a lookup table, such as the lookup table 200 of fig. 2, to obtain the induction flux values that are mapped to the determined current values.

The control processor 305 and/or the central controller 315 monitors the magnetic flux feedback obtained from the magnetometer 307 during movement or at the end of movement of the spool 306 in a measurement step 410. In certain implementations, the control processor 305 and/or the central controller 315 monitors the inductive flux feedback obtained from the inductive sensor 301 during the movement of the measurement step 408 or at the end of the movement of the spool 306.

The expected and measured magnetic flux values are compared in an evaluation step 412 to determine if the values match or match within a predetermined tolerance. If the values match or match within a predetermined tolerance, the sequence of operations branches back to receiving the command 404 at block 414. If the values do not match or do not match within a predetermined tolerance, the operational sequence branches at block 414 to corrective action step 416. A mismatch value indicates that the position of the spool 306 deviates from expected.

In some examples, the corrective action step 416 records an error message for the system. In some examples, the corrective action step 416 issues an alert (e.g., to the user interface 317) indicating a possible system failure. In some examples, the corrective action step 416 prompts the operator to adjust the current applied to the solenoid 312. In some examples, the corrective action step 416 automatically adjusts the current applied to the solenoid 312. In some examples, the corrective action step 416 automatically closes the valve assembly 300 or the entire system. In some examples, the corrective action step 416 prompts the user (e.g., via the user interface 317) to shut down the valve assembly 300 or the entire system.

Fig. 5 shows a hydraulic system 400 for an excavator that includes a control unit 302 according to the principles of the present disclosure. Hydraulic system 400 includes hydraulic actuators 402 (e.g., hydraulic cylinders, hydraulic motors, etc.) distributed throughout the system. The actuators include hydraulic cylinders 402 a-402 c for controlling movement of the boom, arm, and bucket of the excavator, and a hydraulic motor 402d for controlling rotation of the excavator cab relative to the rails. The hydraulic actuator 402 is controlled by a valve 404, which is controlled by a solenoid 406. The control units 302 are each assigned to one of the given solenoids 406, and thus are distributed throughout the system to provide a distributed control system. The control unit 302 is shown mounted to each solenoid 406, but may be mounted to a valve block or elsewhere, relatively close to their designated solenoids. A communication protocol (e.g., ethernet, CAN bus) may be used as part of the network (e.g., with wired and optionally wireless communication capabilities) to coordinate the operation of the control unit 302 through the central control 408. Wiring may be used to provide power to the control unit 302 and solenoid 406 and to allow communication between the various electronic components of the system. The wiring may include a harness 410 that branches off from a center cable or cable.

Fig. 6 shows one of the control units 302 coupled to a poppet-type proportional valve 500, which controls hydraulic fluid flow between first and second ports 502a, 502 b. The poppet 504 of the valve 500 is moved by a solenoid 506. The control unit 302 controls the current provided to the solenoid 506 and senses the magnetic flux feedback during or at the end of the poppet valve 504 movement. In certain examples, the control unit 302 also senses inductive flux feedback during or at the end of the movement of the poppet valve 504. The control unit 302 or central controller 508 looks up or otherwise obtains the desired magnetic flux and/or inductive flux values for the current provided to the solenoid 506. The comparison between the sensed value and the expected value can be used in the same manner as described above to determine whether corrective action is required. The control unit 302 interfaces with a central controller 508 and controls the current supplied to the solenoid 506 based on operator commands received from a control interface 510.

Example aspects of the disclosure

Aspect 1. A valve assembly, comprising:

an adjustment member mounted within the bore of the valve housing, the adjustment member being movable between a plurality of open positions allowing fluid flow through a port of the valve housing and a closed position preventing fluid flow through the port;

a solenoid linear actuator adapted to linearly drive the adjustment member between a closed position and a plurality of open positions; and

a magnetometer adapted to measure magnetic flux passing through at least a portion of the solenoid linear actuator,

wherein the magnetic flux value measured by the magnetometer corresponds to the linear position of the adjustment member relative to the port.

Aspect 2. The valve assembly of aspect 1, wherein the regulating member is one of a flow regulating member or a pressure regulating member.

Aspect 3. The valve assembly of any preceding aspect, further comprising a current meter measuring current in the solenoid linear actuator, wherein a value of current in the solenoid linear actuator measured by the current meter is mapped to a desired magnetic flux value measured by the magnetometer.

Aspect 4. The valve assembly of aspect 3, wherein the current values are also mapped to desired inductance values in the solenoid linear actuator.

Aspect 5. The valve assembly of aspects 1-2, wherein a lookup table is generated and stored in memory that maps each of a plurality of current values in the solenoid linear actuator to a corresponding desired magnetic flux value or a corresponding pair of magnetic flux inductances, wherein the magnetic flux values or pairs of magnetic flux inductances correspond to unique linear positions of the regulating member relative to the port.

Aspect 6. The valve assembly of aspect 5, wherein for a given current value provided to the solenoid, a magnetic flux or pair of flux inductances is measured and used as feedback that is compared to a stored expected magnetic flux value or expected pair of flux inductances corresponding to the given current value to determine whether to perform a corrective action.

Aspect 7. The valve assembly of aspect 6, wherein the corrective action comprises adjusting current in the solenoid.

Aspect 8. The valve assembly of aspect 7, wherein the corrective action comprises shutting down a system comprising the valve assembly.

Aspect 9. A valve assembly according to any preceding aspect, wherein the fluid flowing through the port is liquid or gas when the regulating member is in one of the open positions.

Aspect 10. A valve assembly according to any preceding aspect, wherein the regulating member is a spool or poppet valve.

Aspect 11. The valve assembly of any preceding aspect, wherein the regulating member is a base of the valve cartridge.

Aspect 12. The valve assembly of any preceding aspect, wherein the magnetometer is an integrated component of the control unit that controls the metered flow through the port.

Aspect 13. A valve assembly according to any preceding aspect, wherein the magnetometer is adapted to measure the magnetic flux vector relative to each of three mutually perpendicular axes in space.

Aspect 14. The valve assembly of aspect 12, wherein the control unit comprises a printed circuit board operatively coupled to the magnetometer, the gyroscope, and the accelerometer.

Aspect 15. A valve assembly according to any preceding aspect, wherein the magnetometer is not positioned in the flow channel of the valve assembly or the system comprising the valve assembly.

Aspect 16. The valve assembly according to aspect 12, wherein the control unit is not positioned in a flow path of the valve assembly or the system comprising the valve assembly, and/or wherein the control unit is not exposed to hydraulic pressure.

Aspect 17. A method of detecting a deviation from a desired position of an adjustment member of a valve assembly in a mechanical system, comprising:

measuring a first magnetic flux value through a solenoid of a valve assembly with a magnetometer for a first current value received by the solenoid to drive linear movement of a regulating member;

comparing the first magnetic flux value to a predetermined desired magnetic flux value corresponding to the first current value; and the number of the first and second groups,

based on the comparison, it is determined whether there is a deviation from the desired position of the adjustment member.

Aspect 18. The method of aspect 17, further comprising: measuring a first inductance value in the solenoid for a first current value received by the solenoid; and comparing the first inductance value to a predetermined desired inductance value corresponding to the first current value, wherein determining whether there is a deviation is also based on comparing the first inductance value to the predetermined desired inductance value.

Aspect 19. The method of aspect 17 or 18, further comprising adjusting the current received by the solenoid until a desired magnetic flux value is measured by the magnetometer.

Aspect 20. The method of aspect 18 or 19, further comprising adjusting the current received by the solenoid until a desired inductance value is measured.

Aspect 21. The method of any of aspects 17 to 20, wherein the desired magnetic flux value is one of a plurality of desired magnetic flux values and the first current value is one of a plurality of current values, wherein the method further comprises generating a look-up table that maps each of the current values to one of the desired magnetic flux values.

Aspect 22. The method of aspect 21, wherein the desired inductance value is one of a plurality of desired inductance values, wherein generating the lookup table includes mapping each of the current values to one of the desired magnetic flux values and one of the desired inductance values.

Aspect 23. The method of any one of aspects 17 to 23, wherein the fluid is a liquid.

Aspect 24. The method of any one of aspects 17 to 23, wherein the fluid is a gas.

Aspect 25. The method of any one of aspects 17-24, wherein the adjustment member is a metering substrate of the valve cartridge.

Aspect 26. The method of any of aspects 17-25, wherein the magnetometer is an integrated component of a control unit that controls metered flow through the port.

Aspect 27. The method according to any one of aspects 17 to 26, wherein the magnetometer is adapted to measure a magnetic flux vector relative to each of three mutually perpendicular axes in space.

The various embodiments described above are provided by way of illustration only and should not be construed to limit the appended claims. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.