Sensorless adaptive valve control system

Abstract

The invention relates to a sensorless adaptive valve control system. A valve control system and method may include control logic configured to couple to a conductor and a movable mechanism such that a back electromotive force (BEMF) peak is generated within the conductor based on movement of the movable mechanism, the control logic further configured to: apply a control voltage to the conductor; detecting a BEMF peak value; determining a peak timing of the BEMF peak; and adjusting a control voltage timing of the control voltage based on the peak timing.

Description

TECHNICAL FIELD

[0001] The present invention relates to valve control, and more particularly to sensorless adaptive control of valve control signals based on detection of actual valve motion. BACKGROUND

[0002] Many industries, including manufacturing, healthcare, and automotive, are experiencing a large-scale automation trend. This automation relies heavily on the execution of on-off valves that are electromagnetic valves. These electromagnetic valves provide bi-directional unidirectional motion with limited range.

[0003] Electromagnetic valves can be implemented as PWM-controlled on-off valves, primarily for flow control in pneumatic and hydraulic systems. Electromagnetic on-off valves offer significant cost savings compared to more expensive solutions based on servo motor-controlled valves.

[0004] Furthermore, PWM-controlled on-off valves mitigate the typical hysteresis problem that affects servo motor valves. Electromagnetic valves can be applied in sprayers for precision agriculture systems, pneumatic control actuators, and fluid control actuators.

[0005] By way of example, electronic solenoids play an important role in the medical field where precise and accurate motion is required, such as during the operation of dialysis and drug delivery machines. Industrial manufacturing can require precise actuation of tens or hundreds of electromagnetic valves, such as in textile manufacturing systems.

[0006] When used in industrial manufacturing, a failure of one electromagnetic valve can affect product quality, can stop a production line, and can even pose a risk to operators. When used in the medical or safety industry, a failure of an electromagnetic valve can result in loss of life.

[0007] Furthermore, as an extension of the electronics industry, electronic solenoids are facing increasing commercial competitive pressures to miniaturize, feature-rich, low-cost, and low-power solenoids. Current technical issues that constrain electromagnetic valves include errors in the opening and closing times of the electromagnetic valve compared to the control signal.

[0008] That is, the effective physical on / off duty cycle can be significantly different from the commanded PWM duty cycle, resulting in a mismatch between the valve opening and closing times. This error can affect the control of the flow, especially when the application control requirements require the valve to operate at high PWM frequencies, making the opening and closing times comparable to the PWM period.

[0009] Control of electromagnetic valves is typically implemented in a feedforward mode. The valve opens (valve open) and closes (valve close) at a given duty cycle.

[0010] The target air or liquid flow is related to the application duty cycle. Due to the feedforward flow control, the precise control of the on / off duty cycle is essential to control the precise actuation of the electromagnetic valve.

[0011] Ensuring accurate and repeatable duty cycles is central to the insertion strategy outlined in the next-generation product development roadmap. Previous attempts utilized error compensation values ​​generated during system calibration routines. However, these system calibration procedures are typically performed once during the valve's initial production run, and sometimes a second time during valve installation.

[0012] Even so, opening and closing times can vary depending on pressure, temperature, valve maintenance, contamination, and fluid viscosity. Therefore, the initial calibration after manufacturing may be inappropriate when the solenoid valve is installed in the field under different conditions.

[0013] As valves age, the error between the commanded PWM duty cycle and the valve's opening and closing times will drift over time. This can invalidate the original calibration.

[0014] Previous attempts have attempted to use external sensors mounted on the solenoid valves to detect their properties. These external sensors increase the footprint of the control hardware, the cost of each monitored solenoid valve, and power consumption, and often require application-specific engineering to ensure proper integration of the solenoid valve and sensor.

[0015] Furthermore, externally coupled sensors present technical challenges in many sterile or harsh environments, rendering them unusable due to environmental exposure. Additionally, external sensors and circuitry typically have a high signal-to-noise ratio, and in some cases, detection may require sufficient power to influence the solenoid's motion during measurement, potentially introducing motion artifacts into otherwise smooth solenoid movement.

[0016] These previous attempts to precisely control the effective on / off duty cycle of valves failed to provide the complete solution the industry demands: low power consumption, low cost, and integrated internal error correction. Finding answers to these questions is crucial, given increasing competitive pressures, rising consumer expectations, and diminishing opportunities for meaningful product differentiation in the market.

[0017] Therefore, electronic solenoids with internal error detection and effective duty cycle correction are still required. As a sub-component in a fully solenoid valve system, the control system, implemented in the control logic, is used to control the solenoid valve and the valves coupled to it.

[0018] When creating a solenoid valve system, the control logic is at the heart of the design, and many different types are available. Control logic is sold as a separate component and can be configured for large-scale applications or custom installations of virtually any type of specialized hardware.

[0019] Therefore, the control logic can be configured to interface with many different components. Some examples include configurations to apply voltage using a drive switch or to detect current passing through a sensor.

[0020] For example, input / output pins on the control logic can be assigned to drive switches or sensor interfaces, passive components can be assigned to input / output pins, sensors within the control logic can be assigned to inputs, clock and sampling time can be set, voltage and current can be set, and other configurable elements of the control logic can be determined. This can be defined in the firmware.

[0021] People have long sought solutions to these problems, but previous developments have not taught or offered any complete solutions. As a result, those skilled in the art have long been unable to solve these problems. Attached Figure Description

[0022] The accompanying figure illustrates a sensorless adaptive valve control system based on a PWM solenoid valve with a switching valve. The figure depicting the valve control system is intended as an example and not a limitation, wherein the same reference numerals are intended to refer to the same parts, and wherein:

[0023] Figure 1 This is a block diagram of a valve control system.

[0024] Figure 2 In the first embodiment Figure 1 The first timing diagram of the valve control system.

[0025] Figure 3A and 3B yes Figure 1 Flowchart of valve control system and Figure 2 The timing diagram.

[0026] Figure 4 In the second embodiment Figure 1 The second timing diagram of the valve control system.

[0027] Figure 5A and 5B yes Figure 1 Flowchart of valve control system and Figure 4 The timing diagram. Detailed Implementation

[0028] In the following description, reference is made to the accompanying drawings, which form a part of this document, illustrating embodiments of a valve control system that can be implemented. It should be understood that other embodiments can be utilized, and structural changes can be made without departing from the scope of a valve control system.

[0029] When the features, aspects, or embodiments of a valve control system are described based on the steps of a process, operation, control flow, or flowchart, it should be understood that these steps may be combined, performed in different orders, omitted, or included as additional steps without departing from the valve control system described herein. It should be understood that although the control flow of the system is disclosed in detail, for example in… Figure 3A , 3B In 5A and 5B, but valve control system 100 is not limited to this, and other methods and steps can be used to implement valve control system.

[0030] The valve control system has been described in sufficient detail to enable those skilled in the art to manufacture and use it, and many specific details have been provided to fully understand the valve control system; however, it is clear that the valve control system can be implemented without these specific details.

[0031] To avoid obscuring the valve control system, some well-known system configurations and descriptions are not disclosed in detail. Similarly, the drawings showing system embodiments are semi-schematic and not drawn to scale; in particular, some dimensions are significantly exaggerated in the drawings for clarity. Typically, the valve control system can operate in any direction.

[0032] As used herein, the terminology system is defined as devices or methods depending on their context of use. As used herein, when shown and described... Figure 2 and Figure 4 When describing the attributes of a timing diagram, including peak values ​​P1, P2, P3, P4, control voltage period S1, and control voltage period S2, the letter "I" can precede the referenced attribute to indicate the current at that referenced attribute, or the letter "T" can precede the referenced attribute to indicate the time at that referenced attribute. As used herein, the term communication coupling refers to the electromotive force or back electromotive force between communication coupling elements. Coupling may also mean contact between elements.

[0033] Now for reference Figure 1 The diagram shows a block diagram of a valve control system 100. The valve control system 100 is described as being implemented using a solenoid 102 that is electrically coupled to an integrated solenoid driver 104 and mechanically coupled to a valve 106.

[0034] It is conceivable that the solenoid 102 can be implemented in a variety of configurations, wherein the components of the solenoid 102 have different layouts, shapes, or positions. The solenoid 102 will be understood as an electromechanical component that uses an electric field induced by a wire to induce back-and-forth movement.

[0035] Here, the solenoid 102 is depicted as including a coil 108 with a movable mechanism that responds to a force applied to the coil 108. Figure 2The control voltage 202 generates a magnetic field that causes the piston to move or otherwise apply mechanical force. The coil 108 may be a conductor wound around the plunger 110. The movable mechanism is communicatively coupled to the coil, such that movement based on the movable mechanism generates a BEMF peak within the coil.

[0036] The movable mechanism is expected to be any type of mechanism that is communicatively coupled to generate a BEMF peak, including, for example, rotary movable mechanisms found in rotating electric motors; or linear movable mechanisms found, for example, in solenoids.

[0037] Those skilled in the art will understand that other terms may be used to describe the movable mechanism, including but not limited to piston, actuator, movable core, movable plug, and plunger. For clarity, the movable mechanism will be referred to as plunger 110 in the following text.

[0038] When the coil 108 of the solenoid 102 is actuated by applying a control voltage 202 to the coil 108, the plunger 110 extends or retracts from the coil 108 depending on the direction of the current and the system components. The position of the plunger 110 when the current flows through the coil 108 is the actuated position.

[0039] Solenoid 102 is shown having a first connection 112 and a second connection 114. The first connection 112 may be coupled to a VM, which may be an actuator power supply voltage, while the second connection 114 may be coupled to a drive switch 116, such as a half-bridge or a low-side switch with a high-side freewheeling diode; the drive switch 116 is contained within an integrated solenoid driver 104.

[0040] Although the first connection 112 of solenoid 102 is described as being connected to the power supply voltage, it is conceivable that the first connection 112 may be optionally connected to ground when using other configurations of the drive switch 116. Furthermore, it is conceivable that the first connection 112 may be optionally connected to a second half-bridge (not shown) to form a full H-bridge of coil 108.

[0041] The solenoid 102 may also include a spring 118 for providing mechanical resistance against the movement of the plunger 110 and for limiting the retraction or extension of the plunger 110 within the solenoid 102 during actuation. Telescopic solenoids are conceivable and can be adapted for use with the valve control system 100.

[0042] These types of solenoids differ in the position of the spring 118 and the design of the plunger 110. A rotary solenoid is another anticipated implementation, and the position and design of the spring 118, as well as the type of motion produced, also differ.

[0043] The integrated solenoid driver 104 may include, for example, a switch controller 120 coupled to the solenoid 102 via a half-bridge. The switch controller 120 should be understood herein as a physical structural component having at least a low-power input and a higher-power output.

[0044] Isolation for protecting delicate control circuitry is also a common structural component of the switch controller 120. The switch controller 120 is often referred to as a gate driver.

[0045] For example, the switch controller 120 can be a high-side or low-side PWM driver. The switch controller 120 can use a pulse width modulation (PWM) signal to control the drive switch 116 to provide voltage to the solenoid 102.

[0046] The switch controller 120 can be implemented as a dedicated IC, discrete transistor, or transformer. The switch controller 120 can also be integrated into a larger IC or IC package.

[0047] For example, the drive switch 116 is envisioned as consisting of an N-channel depletion-type MOSFET, an insulated-gate bipolar transistor (IGBT), or a combination of an N-channel depletion-type MOSFET and a P-channel depletion-type MOSFET. The switch controller 120 can provide a PWM signal to the drive switch 116. The PWM signal can provide ON and OFF voltages.

[0048] The integrated solenoid driver 104 may also include a current sensor 122 coupled to the solenoid 102. The current sensor 122 can detect the current through the coil 108 of the solenoid 102. Figure 2 The current is 204. More specifically, the current sensor 122 is configured to detect... Figure 2 and Figure 4 The BEMF peak values ​​are P1, P2, P3, or P4.

[0049] The current sensor 122 should be understood herein as a physical structural component having at least structural input and output connections. However, various forms of the current sensor 122 are conceivable, including Hall effect linear sensors, electrically isolated sensors, or GMR-based sensors. Other forms are also considered, including fluxgate sensors, shunt resistors, and even fiber optic interferometer-based sensors.

[0050] The analog current detected by current sensor 122 can be digitized by a current analog-to-digital converter (IADC 124). The digitized current, such as current 204, is provided to control logic 126 for processing. Control logic 126 is configured to determine a first timing of one of the back electromotive force peaks P1, P2, P3, and P4, and is configured to... Figure 2 During subsequent cycles 206, the second timing of the control voltage 202 is adjusted based on the first timing.

[0051] Control logic 126 is understood herein as a physical structural component having at least transistor logic gates for providing computation and control. Furthermore, control logic 126 includes structural inputs and outputs that typically operate between 0 and 5 volts. Control logic 126 is expected to be based on a TTL or CMOS architecture, but may also include other logic families such as RTL, DTL, and ECL.

[0052] The control logic 126 can be of high or low complexity. For example, in some more complex control logic 126, the current sensor 122 and IADC 124 may be located inside the control logic 126, while other less complex controllers may have I / O pins assigned for interfacing with these external components.

[0053] The control logic 126 may internally include components of the integrated solenoid driver 104, or it may be externally coupled to it. The integrated solenoid driver 104 may be a single chip, multiple chips within a package, or multiple components within a single package. Distributed configurations are also possible.

[0054] Control logic 126 can analyze voltage 202 and current 204 in the digital domain to determine the error between the actual piston opening and the control signal, and calculate the error offset. For example, control logic 126 can determine the timing of any one of the BEMF peaks P1, P2, P3, and P4. These BEMF peaks correspond to the movement of piston 110.

[0055] The integrated solenoid driver 104 may also include a voltage sensor 128 coupled to the solenoid 102. The voltage sensor 128 can detect the voltage 202 across the coil 108 of the solenoid 102, and when the solenoid 102 is in a certain state... Figure 4 It is used in the three-state 406 and is used for detection. Figure 4 The BEMF peak value is P3 or P4.

[0056] The analog voltage detected by voltage sensor 128 can be digitized by voltage analog-to-digital converter (VADC 130). The digitized voltage, such as voltage 202, is provided to control logic 126 for processing.

[0057] At the other end of the valve control system 100, valve 106 may include valve piston 132 mechanically connected to plunger 110 of solenoid 102. Valve 106 is depicted as a simple normally closed on / off valve in the closed position, with plunger 110 and valve piston 132 retracted.

[0058] It is conceivable that valve 104 can be implemented in a variety of configurations, where the components of valve 104 have different layouts, shapes, or positions. Valve 104 will be understood as a mechanical component that restricts or controls flow.

[0059] When open, plunger 110 and valve piston 132 extend, connecting input line 134 to output line 136 via piston connection 138. When valve 106 is closed, input line 134 is blocked by valve piston 132. Consider other valves, including normally open valves, valves with multiple solenoids, and even more input and output lines.

[0060] It has been found that, regardless of whether it is through such Figure 2 The current shown is still as Figure 4 The BEMF peak values ​​of the voltage measurements shown can be a good indicator of the need for maintenance action. For example, if P1, P2, P3, or P4 exceeds the time threshold of 140 for event S1 or S2, this can indicate that service action is required.

[0061] It can also be envisioned that the magnitude of the BEMF peak in terms of current or voltage can be used to identify whether a service action is required. The amplitude can be between P1 and P2, or between P3 and P4, or exceed a current threshold 142 or a voltage threshold 144. If it exceeds the current threshold 142 or the voltage threshold 144, this can indicate that a service action is required. Therefore, determining a service action can be based on the timing or amplitude of the BEMF peak.

[0062] Service actions may include maintenance, cleaning, replacement, or repair of valves or solenoid valves. The time threshold 140 may be a threshold based on the time between BEMF peak values ​​P1, P2, P3, or P4 and S1, S2. The time threshold 140 may also be a threshold based on the time between the BEMF peak value and events S1 or S2. Finally, the time threshold 140 may be a threshold based on a percentage of the control voltage's duty cycle.

[0063] It should be understood that control logic 126 can be configured to couple to coil 108 and plunger 110, thereby generating a back electromotive force (BEMF) peak within coil 108 based on the moving movable mechanism. Control logic 126 can also be configured to: apply a control voltage to coil 108 using drive switch 116; and utilize... Figure 3A , 3B Peak detection of 5A and 5B and detection of BEMF peak value by current sensor 122 coupled to current analog-to-digital converter 124; determination of peak timing of BEMF peak value using digital sampling of current or voltage, and adjustment of control voltage timing of control voltage based on peak timing.

[0064] Now for reference Figure 2 The first embodiment is shown. Figure 1A first timing diagram 200 for the valve control system 100. The first timing diagram 200 displays time along the horizontal axis and voltage and current along the vertical axis.

[0065] The control voltage 202 is shown as a square wave, indicated by dashed lines, starting at S1 and ending at S2. The control voltage can also be PWM modulated to achieve optimal control of the solenoid valve. In this case, the dashed lines represent the average value of the PWM signal. A response to the control voltage 202 is also shown via… Figure 1 The current in coil 108 is 204.

[0066] Between S1 and S2, control voltage 202 represents a control voltage ON signal, while between S2 and subsequent cycles 206, control voltage 202 represents a control voltage OFF signal. This configuration is provided for clarity and ease of understanding. However, it is conceivable that the valve control system 100 may use other configurations, including configurations with reverse voltage and current, and configurations with multiple solenoids.

[0067] Timing of control voltage 202 and Figure 1 The error between the actual opening and closing of valve 106, represented by the local minimum and local maximum values ​​within current 204, can be approximated by Equation 1, as shown below:

[0068]

[0069] Wherein, “αr” represents the actual mechanical duty cycle, “α” represents the command electrical duty cycle, “Tso” represents the on time, “Tsc” represents the off time, “Tdc” represents the off delay time, “Tdo” represents the on delay time, “Ttc” represents the off displacement time, “Tto” represents the on displacement time, and “TPWM” represents the time of one PWM control signal ON-OFF cycle.

[0070] Tso, Tsc, Tdc, Tdo, Ttc, Tto, and TPWM represent durations, as shown in the attached diagram. Figure 2 The symbols and symbols are shown in the figure. Tso can be expressed as the sum of Tdo and Tto, while Tsc can be expressed as the sum of Tdc and Ttc. Equation 1 assumes a linear approximation to simulate the displacement during Ttc and Tto, which is generally a reasonable assumption.

[0071] The valve control system 100 consists of an adaptive control algorithm, in which the inflow is monitored. Figure 1 The current 204 of the solenoid 102 is measured and local maxima and minima are detected within the current distribution. For each ON-OFF cycle of the control voltage 202, the delay times Tdo and Tdc, and the displacement times Tto and Ttc are measured. The local maxima are designated as P1 and P3, while the local minima are designated as P2 and P4.

[0072] Specifically, P1 depicts the local maximum value during the opening time Tso, while P2 depicts the local minimum value during the opening time Tso. P1 represents the initial movement of the plunger 110 after a delay Tdo measured from the start of the control voltage S1.

[0073] P2 indicates the end of the movement of plunger 110. P3 depicts the local minimum during the closing time Tsc, while P4 depicts the local maximum during the closing time Tsc.

[0074] IP1 can be understood as Ion, or the current when valve 106 is open and begins to open. IP3 can be understood as Ioff, or the current when valve 106 is closed and begins to move to close.

[0075] Peak values ​​P1, P2, P3, and P4 are generated by Figure 1 The back electromotive force (BEMF) generated by the movement of the plunger 110 can provide information about the ON-OFF state and movement of the valve 106. The detection of these local maximum and minimum peaks can be done in analog, but more commonly in the digital domain. In this case, an ADC is used to digitize the current 204, which is then... Figure 1 The control logic 126 is used for processing.

[0076] The PWM control signals are described as S1, corresponding to the control voltage ON signal, and S2, corresponding to the control voltage OFF signal. TS1 and TS2 are known to control logic 126 because they originate from control logic 126. It is conceivable that the ON and OFF signals can be high voltage and low voltage as shown in the figure, but they can also be reversed so that low voltage is ON and high voltage is OFF. Furthermore, the ON and OFF signals can include positive voltage and negative voltage.

[0077] P1, P2, P3, and P4 can be located by detecting the local maxima and minima in the waveform of current 204. Multiple circuits can be used for detection. If processing in the digital domain, one approach is to compare each current sample with its previous sample until a change in slope is detected. Figure 3A and 3B The algorithm is shown in more detail.

[0078] Based on these local maximum and minimum peak values, control logic 126 can calculate the parameters of interest as follows:

[0079] Tdo = TP1 - TS1 Equation 2

[0080] Equation 3: Tto = TP2 - TP1

[0081] Equation 4: Tdc = TP3 - TS2

[0082] Ttc = TP4 - TP3 Equation 5

[0083] TP1, TP2, TP3, and TP4 represent the corresponding times of the reference local maximum or minimum values. TS1 and TS2 represent the times of event S1 or event S2, respectively. These parameters are sufficient to calculate the error of Equation 1.

[0084] Although the valve control system 100 is depicted as having a high control voltage 202 for opening the valve 106, it is conceivable that other circuit layouts may also be used, including a high-voltage control voltage 202 for closing the valve 106.

[0085] Now for reference Figure 3A , which shows Figure 1 The first part of the flowchart 300 of the valve control system 100 and Figure 2 The timing diagram 200. These operating steps of the valve control system 100 can be utilized in... Figure 1 The instructions running on the processor or control logic 126 control the technical process or the internal functions of the control logic 126.

[0086] The control flow can begin in solenoid inactivity step 302, where the sampled current (IS) is approximately zero, the sampled voltage (VS) is approximately zero, and the solenoid is inactive. VON step 304 can be initiated in S1 to turn on the solenoid. Figure 2 The control voltage 202 is applied during this period. Figure 1 The coil 108. When VON step 304 is started, the IP1 current variable is set to zero, and the TON counter is started.

[0087] Once VON step 304 is completed, P1 wait step 306 can be initiated. During P1 wait step 306, control logic 126 will wait for one or more clock periods before sampling IS.

[0088] Once IS is sampled, IP1 increment decision 308 can be determined. If IS is higher than the previously set IP1, IP1 increment decision 308 will return a True value and IP1 update step 310 will be executed, which sets IP1 to IS, i.e., the last sampled current.

[0089] During IP1 update step 310, Tdo is set to Tnow-TS1, which is the current clock period since the S1 event. If IS is lower than the previously set IP1, the IP1 increment decision 308 can return a False value, and it can be determined that IP1 exceeds the threshold decision 312.

[0090] If IS is not lower than the previously set IP1 minus the threshold, then the IP1 exceeds the threshold decision 312 will return a False value, and the valve control system 100 can re-execute the P1 waiting step 306. If IS is lower than the previously set IP1 minus the threshold, then the IP1 exceeds the threshold decision 312 can return a True value. The IP1 exceeds the threshold decision 312 can ensure that the detection of P1 is not caused by... Figure 2 It is triggered by noise or small fluctuations in the current 204.

[0091] It has been found that the steps taken to identify P1, including waiting step 306, IP1 increment decision 308, and IP1 update step 310, can together determine the local maximum value P1 located during Tso. P1 represents the time when valve 108 begins to move. It has also been found that the identification of P1 allows for the calculation of the time from S1 (control voltage 202ON event) to... Figure 1 The time Tdo, or delay time, is the time it takes for valve 106 to begin moving at P1. Decision 312, which determines when IP1 exceeds the threshold, also helps avoid overly sensitive triggering.

[0092] Once IP1 exceeds the threshold decision 312 and returns a True value, the valve control system 100 can identify Tdo as Tnow-TS1 and execute the IP2 update step 314. During the IP2 update step 314, IP2 is set to IS, i.e., the last sampled current. Furthermore, during the IP2 update step 314, Tto is set to Tnow-Tdo, which is the current clock period since the Tdo event.

[0093] After performing IP2 update step 314, valve control system 100 can perform P2 wait step 316. During P2 wait step 316, control logic 126 will wait for one or more clock periods before sampling IS.

[0094] Once IS is sampled, IP2 reduction decision 318 can be determined. If IS is lower than the previously set IP2, IP2 reduction decision 318 will return a True value, and IP2 update step 314 will be re-executed.

[0095] If IS is higher than the previously set IP2, the IP2 decrease decision 318 can return a False value, and the IP2 increase decision 320 can be determined. If IS is not higher than IP2, a False value can be returned, meaning that a local P2 minimum has not yet been identified, and the P2 wait step 316 can be re-executed. If IS is higher than IP2, the IP2 increase decision 320 can return a True value, and the valve control system 100 can identify Tto as Tnow-Tdo.

[0096] It has been found that the steps taken to identify P2, including IP2 update step 314, P2 wait step 316, IP2 decrease decision 318, and IP2 increase decision 320, can together determine a local minimum P2, which is localized during Tso. P2 represents the time it takes for valve 108 to stop moving and complete its cycle. It has also been found that identifying P2 allows for the calculation of Tso, or the time for valve 106 to be fully open, starting from S1 (control voltage 202ON event) and extending to the time when valve 106 stops moving at P2.

[0097] Once IP2 increment decision 320 returns a True value identifying the local minimum P2, the valve control system 100 can execute S2 waiting step 322. It is conceivable that a threshold, such as the threshold used in IP1 exceeding threshold decision 312, could be used in conjunction with IP2 decrease decision 318 and IP2 increment decision 320 to make the determination less sensitive to noise. However, to avoid obfuscating the valve control system 100, these are not shown.

[0098] Steps: P1 wait step 306, IP1 increase decision 308, IP1 update step 310, IP1 exceeds threshold decision 312, IP2 update step 314, P2 wait step 316, IP2 decrease decision 318 and IP2 increase decision 320 can be regarded as Tso measurement or open time measurement.

[0099] During the S2 wait step 322, control logic 126 maintains sampling of current 204 at the internal clock speed and keeps updating the IP3 variable until the valve is commanded OFF; that is, when control voltage 202 OFF. When this occurs, S2 event decision 324 can return a True value.

[0100] If control voltage 202 remains ON and is not removed from coil 108, event decision 324 will return a false value, and IP3 update step 326 will be executed, where IP3 is set to IS. Once IP3 is set to IS, wait step 322 can be re-executed.

[0101] If control voltage 202 is OFF and removed from coil 108, the S2 event decision 324 will return a True value, indicating that an S2 event has been detected. When an S2 event is detected, the valve control system 100 can... Figure 3B The control flow is started at 3B1.

[0102] Now for reference Figure 3B , which shows Figure 1 The second part of the flowchart 300 of the valve control system 100 and Figure 2Timing diagram 200. Valve control system 100 can begin at 3B1 with P3 waiting step 328. During P3 waiting step 328, Figure 1 The control logic 126 will wait for one or more clock periods before sampling IS.

[0103] Once IS is sampled, IP3 reduction decision 330 can be determined. If IS is lower than the previously set IP3, IP3 reduction decision 330 will return to True and IP3 update step 332 will be executed, which sets IP3 to IS, i.e., the last sampled current.

[0104] During IP3 update step 332, Tdc is set to Tnow-TS2, which is the current clock period since event S2. After IP3 update step 332, valve control system 100 can then re-execute P3 waiting step 328. If IS is higher than the previously set IP3, IP3 decrease decision 330 can return a False value, and IP3 can be determined to have exceeded the threshold decision 334.

[0105] If IS is not higher than the previously set IP3 plus the threshold, then the IP3 exceeding the threshold decision 334 will return a False value and re-execute the P3 waiting step 328. If IS is higher than the previously set IP3 plus the threshold, then the IP3 exceeding the threshold decision 334 can return a True value. The IP3 exceeding the threshold decision 334 ensures that the detection of P3 will not be... Figure 2 Noise or small fluctuations in the current 204 trigger the process. Once IP3 exceeds the threshold decision 334 returns a True value, the valve control system 100 can identify Tdc as Tnow-TS2 and execute the IP4 update step 336.

[0106] It has been found that the steps taken to identify P3, including P3 waiting step 328, IP3 reduction decision 330, and IP3 update step 332, can together determine the local minimum P3, which is located during Tsc. P3 represents... Figure 1 The time when valve 108 begins to move. Further investigation revealed that the identification of P3 allows for the calculation of the time from S2 (control voltage 202OFF event) to... Figure 1 The time Tdc, or delay time, at which valve 106 begins to move at P3. Decision 334, which determines when IP3 exceeds the threshold, also helps avoid oversensitive triggering.

[0107] During IP4 update step 336, IP4 is set to IS, the last sampled current. Additionally, during IP4 update step 336, Ttc is set to Tnow-Tdc, which is the current clock duration since the Tdc event. After performing IP4 update step 336, the valve control system 100 can perform P4 wait step 338. During P4 wait step 338, control logic 126 will wait for one or more clock durations before sampling IS.

[0108] Once IS is sampled, IP4 increase decision 340 can be determined. If IS is higher than the previously set IP4, IP4 increase decision 340 will return a True value, and IP4 update step 336 will be re-executed.

[0109] If IS is lower than the previously set IP4, the IP4 increase decision 340 can return a False value, and the IP4 decrease decision 342 can be determined. If IS is higher than IP4, a False value can be returned, meaning that the local P4 minimum has not yet been identified, and the P4 wait step 338 can be re-executed. If IS is lower than IP4, the IP4 decrease decision 342 can return a True value, and the valve control system 100 can identify Ttc as Tnow-Tdc.

[0110] It has been found that the steps taken to identify P4, including IP4 update step 336, P4 wait step 338, IP4 increase decision 340, and IP4 decrease decision 342, can together determine the local maximum value P4, which is localized during Tsc. P4 represents the time it takes for valve 108 to stop moving and complete its cycle. It has also been found that identifying P4 allows for the calculation of Tsc, or the time for valve 106 to be fully closed, starting from S2 (control voltage 202 OFF event) and extending to the time when valve 106 stops moving at P4.

[0111] Once IP4 decrease decision 342 returns a True value identifying the local maximum P4, valve control system 100 can execute parameter step 344. Expected thresholds, such as those used in IP3 exceeding threshold decision 334, can be used in conjunction with IP4 increase decision 340 and IP4 decrease decision 342 to make the decisions less sensitive to noise. However, these are not shown to avoid obfuscating valve control system 100.

[0112] Steps: P3 waiting step 328, IP3 decrease decision 330, IP3 update step 332, IP3 exceeds threshold decision 334, IP4 update step 336, P4 waiting step 338, IP4 increase decision 340 and IP4 decrease decision 342 can be regarded as Tsc measurement or shutdown time measurement.

[0113] Parameter step 344 can provide variables Tso, Tdo, Tto, Tsc, Tdc, and Ttc. These parameters can be used to calculate the error step 346 according to Equation 6, as follows:

[0114]

[0115] Once the error is calculated in error calculation step 346, the valve control system 100 can execute TON control step 348 according to equation 7, as shown below:

[0116] TON CNT =TS2-TS1-Err Equation 7

[0117] TONCNT is the control voltage 202, which includes the Err offset of the adjustment time. This will compensate for the mismatch between the control voltage signal and the response of valve 106.

[0118] TONCNT can be the control voltage ON timing of the subsequent cycle 206 of control voltage 202. As will be understood, TONCNT can be based on one or more BEMF peaks. Furthermore, the control signal used for control voltage OFF timing or for control voltage ON / OFF can also be determined based on one or more BEMF peaks.

[0119] The control voltage 202 can provide regulation to control the time when valve 106 begins to open at P1, stops opening at P2, begins to close at P3, and stops closing at P4. Depending on the application, each of these peak values ​​can be controlled and calibrated in each open-close cycle of valve 106.

[0120] Once the new TON is calculated in the TON calculation control step 348, this value can be used to set the timing of the next S1 or control voltage 202ON event. The valve control system 100 will execute the wait in step S1 350, which will... Figure 3A The VON is started in step 304 because the valve control system is in Figure 3A Continue at 3A1.

[0121] The local maxima P1 and P3, and the local minima P2 and P4, can be understood as the peak values ​​during the ON-OFF control cycle of the control voltage 202. The first two peaks, P1 and P2, can divide the start and end of valve 106 movement during the open cycle and can also be used to determine the delay between the control voltage ON signal and the start of movement. Similarly, the second two peaks, P3 and P4, can divide the start and end of valve 106 movement during the close cycle and can also be used to determine the delay between the control voltage OFF signal and the start of movement.

[0122] Unexpectedly, it was discovered that the calculation error and the new error-based control voltage allow the valve control system 100 to operate the valve 106 with a high degree of timing accuracy, unaffected by heat, contamination, humidity, or other environmental factors that may alter the valve speed in practice. Instead, the valve control system 100 can be adjusted to account for these parameters during each cycle.

[0123] Furthermore, it has been found that the valve control system 100 can operate with high timing accuracy without being negatively affected by fluid viscosity, fluid purity, or other properties of the materials within the valve, which in practice can alter the valve's speed. Moreover, the valve control system 100 can operate with high accuracy even during valve aging or throughout the maintenance cycle, delaying maintenance because the valve will be continuously calibrated in each cycle as it ages or undergoes maintenance changes, whereas calibration is typically only performed during initial production.

[0124] Now for reference Figure 4 The second embodiment is shown therein. Figure 1 The second timing diagram 400 of the valve control system 100. Timing diagram 400 is applicable to... Figure 1 The plunger 110 in Figure 1 The coil 108 closes after being completely de-energized. The first timing diagram 400 displays the time along the horizontal axis and the voltage and current along the vertical axis.

[0125] The control voltage 402 is shown as a square wave, starting at S1 and ending at S2, represented by dashed lines. The control voltage can also be PWM modulated for optimal control of the solenoid valve. In this case, the dashed lines represent the average value of the PWM signal. The control voltage 402 is also shown as a BEMF voltage spike that occurs after the coil current 404 becomes zero. This is likely due to friction or eddy currents stored in the solenoid valve core delaying mechanical movement, thus occurring when the solenoid valve is completely de-energized. To simplify the observation of the BEMF spike, the driver is in a tri-state 406 once the current reaches zero; as shown below with respect to the tri-state command step 548 of Figure 5, the measured voltage 402 of P3 and P4 is observed instead of the current 404. The current 404 flowing through coil 108 is also shown in response to the control voltage 402.

[0126] Timing of control voltage 402 and Figure 1 The error between the actual opening and closing of valve 106, represented by the local minimum and local maximum values ​​within the current 404 and voltage 402 curves, can be approximated by the above equation 1.

[0127] The valve control system 100 consists of an adaptive control algorithm, in which the inflow is monitored. Figure 1The current 404 of solenoid 102 and the voltage 402 of the driver when it is in a tri-state 406 are measured. For each ON-OFF cycle of the control voltage 402, delay timings Tdo and Tdc, and displacement timings Tto and Ttc are measured. When the valve is open, local maxima and local minima in the current curve are detected. When the valve is closed, local maxima and local minima in the voltage distribution are detected. Local maxima are designated as P1 and P3, while local minima are designated as P2 and P4.

[0128] Specifically, P1 depicts the local maximum during the on-time Tso, while P2 depicts the local minimum during the on-time Tso. Similarly, P3 depicts the local minimum during the off-time Tsc, while P4 depicts the local maximum during the off-time Tsc.

[0129] IP1 can be understood as Ion, which is the current when the valve is open and begins to open. VP4 can be understood as the peak BEMF voltage when the valve is closed and begins to close.

[0130] Peak values ​​P1, P2, P3, and P4 are caused by the back electromotive force (BEMF) generated by the movement of plunger 110, and therefore can provide information about the ON-OFF state and movement of valve 106. When coil 108 is de-energized, the BEMF peaks will be observed in the voltage of the coil rather than the current.

[0131] The detection of these local maximum and minimum peaks can be done in analog, but more commonly in the digital domain. In this case, the ADC is used to digitize the current 404 and voltage 402, which are then processed by... Figure 1 The control logic 126 is used for processing.

[0132] The PWM control signals are described as S1, corresponding to the ON command, and S2, corresponding to the OFF command. TS1 and TS2 are known to control logic 126 because they originate from control logic 126.

[0133] P1 and P2 can be found by detecting local maxima and minima in the waveform of current 404. P3 and P4 can be found by detecting local maxima and minima in the waveform of voltage 402 across solenoid 402. Multiple circuits can be used for detection. If processing in the digital domain, one approach is to compare each current sample with its previous sample until a change in slope is detected. Figure 5A and 5B The algorithm is shown in more detail.

[0134] Based on these local maximum and minimum peak values, control logic 126 can calculate the parameters of interest based on equations 2-5 above.

[0135] TP1, TP2, TP3, and TP4 represent the corresponding times of the reference local maximum or minimum values. TS1 and TS2 represent the times of event S1 or event S2, respectively. These parameters are sufficient to calculate the error of Equation 1.

[0136] When the plunger 110 closes after the coil 108 is completely de-energized, a three-state state 406 is shown. This indicates that... Figure 1 The integrated solenoid driver 104 neither pulls up nor down Figure 1 The second connection 114 also did not pull up or down when the integrated solenoid driver 104 was in a high-impedance state. Figure 1 The second connection 114 in the middle is in a high-resistance state between the second connection 114 and the high voltage or low voltage.

[0137] Although the valve control system 100 is depicted as having a high control voltage 402 for opening the valve 106, it is conceivable that other circuit layouts may also be used, including a high-voltage control voltage 402 for closing the valve 106.

[0138] Now for reference Figure 5A , which shows Figure 1 The first part of the flowchart 500 of the valve control system 100 and Figure 4 The timing diagram 400 includes Figure 1 After coil 108 is completely de-energized Figure 1 The conditions under which the plunger 110 closes. These operating steps of the valve control system 100 can be utilized in... Figure 1 The control logic 126 is implemented by instructions running on it, and the control logic 126 controls the technical process or the internal function of the control logic 126.

[0139] The control flow can begin in solenoid inactivity step 502, where the sampled current (IS) is approximately 0, the sampled voltage (VS) is approximately 0, and the solenoid is inactive. VON step 504 can be initiated in S1 to turn on the solenoid. Figure 4 The control voltage 402 is applied to the coil 108 during this period. When VON step 504 is started, the IP1 current variable is set to 0, and the TON counter is started.

[0140] Once VON step 504 is completed, P1 wait step 506 can be initiated. During P1 wait step 506, control logic 126 will wait for one or more clock cycles before sampling IS.

[0141] Once IS is sampled, IP1 increment decision 508 can be determined. If IS is higher than the previously set IP1, IP1 increment decision 508 will return a True value, and IP1 update step 510 will be executed, which sets IP1 to IS, i.e., the last sampled current.

[0142] During IP1 update step 510, Tdo is set to Tnow-TS1, which is the current clock cycle number since the S1 event. If IS is lower than the previously set IP1, the IP1 increment decision 508 can return a False value, and it can be determined that IP1 exceeds the threshold decision 512.

[0143] If IS is not lower than the previously set IP1 minus the threshold, then the IP1 exceeding the threshold decision 512 will return a False value, and the valve control system 100 will re-execute the P1 waiting step 506. If IS is lower than the previously set IP1 minus the threshold, then the IP1 exceeding the threshold decision 512 can return a True value. The IP1 exceeding the threshold decision 512 ensures that the detection of P1 will not be... Figure 4 Noise or small fluctuations in the current 404 trigger the circuit.

[0144] It has been found that the steps taken to identify P1, including waiting step 506, IP1 increment decision 508, and IP1 update step 510, can together determine the local maximum value P1, which is located during Tso. P1 represents the time when valve 108 begins to move. It has also been found that the identification of P1 allows calculations to extend from S1 (control voltage 402ON event) to... Figure 1 The time Tdo, or delay time, for which valve 106 begins to move at P1. Decision 512, which determines when IP1 exceeds the threshold, also helps avoid oversensitive triggering.

[0145] Once IP1 exceeds the threshold and decision 512 returns a True value, the valve control system 100 can identify Tdo as Tnow-TS1 and execute IP2 update step 514. During IP2 update step 514, IP2 is set to IS, i.e., the last sampled current. Furthermore, during IP2 update step 514, Tto is set to Tnow-Tdo, which is the current clock cycle number since the Tdo event.

[0146] After performing IP2 update step 514, valve control system 100 can perform P2 wait step 516. During P2 wait step 516, control logic 126 will wait for one or more clock cycles before sampling IS.

[0147] Once IS is sampled, IP2 reduction decision 518 can be determined. If IS is lower than the previously set IP2, IP2 reduction decision 518 will return a True value, and IP2 update step 514 will be re-executed.

[0148] If IS is higher than the previously set IP2, the IP2 decrease decision 518 can return a False value, and the IP2 increase decision 520 can be determined. If IS is not higher than IP2, a False value can be returned, meaning that the local P2 minimum has not yet been identified, and the P2 wait step 516 can be re-executed. If IS is higher than IP2, the IP2 increase decision 520 can return a True value, and the valve control system 100 can identify Tto as Tnow-Tdo.

[0149] It has been found that the steps taken to identify P2, including IP2 update step 514, P2 wait step 516, IP2 decrease decision 518, and IP2 increase decision 520, can together determine the local minimum P2, which is localized during Tso. P2 represents the time it takes for valve 108 to stop moving and complete its cycle. It has also been found that the identification of P2 allows for the calculation of Tso, the time for valve 106 to be fully open, starting from S1 (control voltage 402 ON event) and extending to the time when valve 106 stops moving at P2.

[0150] Once IP2 increment decision 520 returns the truth value identifying the local minimum P2, valve control system 100 can execute S2 waiting step 522. An expected threshold, such as the threshold used in IP1 exceeding threshold decision 512, can be used in conjunction with IP2 decrease decision 518 and IP2 increment decision 520 to make the decision less sensitive to noise. However, these are not shown to avoid obfuscating valve control system 100.

[0151] Steps: P1 waiting step 506, IP1 increase decision 508, IP1 update step 510, IP1 exceeds threshold decision 512, IP2 update step 514, P2 waiting step 516, IP2 decrease decision 518 and IP2 increase decision 520 can be regarded as Tso measurement or open time measurement.

[0152] During the S2 wait step 522, control logic 126 maintains sampling of current 404 at the internal clock speed and keeps updating the IP3 variable until the valve is commanded OFF; that is, when control voltage 402 OFF. When this occurs, S2 event decision 524 can return a True value.

[0153] If control voltage 402 remains ON and is not removed from coil 108, event decision 524 will return a false value, and IP3 update step 526 will be executed, where IP3 is set to IS. Once IP3 is set to IS, wait step 522 can be re-executed.

[0154] If control voltage 402 is turned off and removed from coil 108, the S2 event decision 524 will return a True value, indicating that the S2 event has been detected or determined. When the S2 event is detected or determined, the valve control system 100 can... Figure 5B The control flow is initiated at 5B1.

[0155] Now for reference Figure 5B , which shows Figure 1 The second part of the flowchart of the valve control system 100 and Figure 4 The timing diagram is 400. The valve control system 100 can begin the P3 waiting step 528 at 5B1. During the P3 waiting step 528, Figure 1 The control logic 126 will wait for one or more clock cycles before sampling IS.

[0156] Once IS is sampled, IP3 reduction decision 530 can be determined. If IS is lower than the previously set IP3, IP3 reduction decision 530 will return to True and IP3 update step 532 will be executed, which sets IP3 to IS, i.e., the last sampled current.

[0157] During IP3 update step 532, Tdc is set to Tnow-TS2, which is the current clock cycle number since event S2. After IP3 update step 532, valve control system 100 can perform current zeroing decision 534.

[0158] The current zeroing decision can be determined by 534. Figure 4 Is the current 404 close to or equal to zero? If the current 404 is not close to or not zero, the current zeroing decision 534 can return a False value, which means... Figure 1 The integrated solenoid driver 104 is not in a tri-state configuration. After the current zeroing decision 534 returns a False value, the valve control system 100 can then re-execute the P3 waiting step 528. It is conceivable that zero or near-zero current may include current that crosses zero and flows in reverse, or current below a percentage threshold of the drive current, such as less than 5% of the drive current.

[0159] During the IP3 reduction decision 530, if IS is higher than the previously set IP3, the IP3 reduction decision 530 can return a False value, and the decision 536 can be determined that IP3 exceeds the threshold. If IS is not higher than the previously set IP3 plus the threshold, the decision 536 that IP3 exceeds the threshold will return a False value and the P3 waiting step 528 will be re-executed.

[0160] If IS is higher than the previously set IP3 plus the threshold, then the IP3 exceeding threshold decision 536 can return a True value. The IP3 exceeding threshold decision 536 can ensure that the detection of P3 is not triggered by noise or small fluctuations in the current 404.

[0161] Once IP3 exceeds the threshold decision 536 and returns a True value, the valve control system 100 can identify Tdc as Tnow-TS2 and execute IP4 update step 538.

[0162] It has been found that the steps taken to identify P3, including P3 waiting step 528, IP3 reduction decision 530, and IP3 update step 532, can together determine the local minimum P3, which is located during Tsc. P3 represents... Figure 1 The time when valve 108 begins to move. Further investigation revealed that the identification of P3 allows for the calculation of the time from S2 (control voltage 402 shut-off event) to... Figure 1 The time Tdc, or delay time, at which valve 106 begins to move at P3. IP3 exceeding the threshold decision 536 also helps avoid overly sensitive triggering.

[0163] During IP4 update step 538, IP4 is set to IS, which is the last sampled current. Additionally, during IP4 update step 538, Ttc is set to Tnow-Tdc, which is the current clock cycle number since the Tdc event. After executing IP4 update step 538, the valve control system 100 can execute P4 wait step 540. During P4 wait step 540, control logic 126 will wait for one or more clock cycles before sampling IS.

[0164] Once IS is sampled, IP4 increase decision 542 can be determined. If IS is higher than the previously set IP4, IP4 increase decision 542 will return a True value, and IP4 update step 538 will be re-executed.

[0165] If IS is lower than the previously set IP4, the IP4 increase decision 542 can return a False value, and the IP4 decrease decision 544 can be determined. If IS is higher than IP4, a False value can be returned, meaning that the local P4 minimum has not yet been identified, and the P4 wait step 540 can be re-executed. If IS is lower than IP4, the IP4 decrease decision 544 can return a True value, and the valve control system 100 can identify Ttc as Tnow-Tdc.

[0166] It has been found that the steps taken to identify P4, including IP4 update step 538, P4 wait step 540, IP4 increase decision 542, and IP4 decrease decision 544, can together determine the local maximum value P4, which is localized during Tsc. P4 represents the time it takes for valve 108 to stop moving and complete its cycle. It has also been found that identifying P4 allows for the calculation of Tsc, the time for valve 106 to be fully closed, starting from S2 (control voltage 402 OFF event) and extending to the time when valve 106 stops moving at P4.

[0167] On the other hand, if the current 404 is close to or equal to zero during the current zeroing decision 534, then the current zeroing decision 534 can return a True value. The valve control system 100 can then implement the three-state command step 548, where in Figure 4 Under the three-state condition 406, the solenoid driver 104 is commanded at a high impedance between the high and low supply voltages. This allows for easier detection of the subsequent BEMF voltage peak caused by mechanical movement when the valve closes. Figure 4 During the three-state state 406, P3 and P4 are determined by the voltage 402, which is measured and digitized using an analog-to-digital converter.

[0168] The valve control system 100 can execute the P3 voltage wait step 550. During the P3 voltage wait step 550, the control logic 126 will wait for one or more clock cycles before sampling the VS.

[0169] Once VS is sampled, a decision 552 is made to determine if VS is below a threshold. If VS is below the voltage threshold VT, the VS below threshold decision 552 returns a True value and executes the Tdc update step 554, which sets Tdc to Tnow-TS2, which is the current clock cycle number since the S2 event. After the Tdc update step 554, the valve control system 100 can re-execute the P3 voltage wait step 550.

[0170] If VS is higher than the voltage threshold VT, return False and identify P3 and Tdc, and perform VP4 update step 556.

[0171] It has been found that the steps taken to identify P3, including the P3 voltage wait step 550, the VS below threshold decision 552, and the Tdc update step 554, can together determine P3, which is located during Tsc. P3 represents the time when valve 108 begins to move. It has been further found that the identification of P3 allows Tdc, or delay time, to be calculated from S2 (control voltage 402 OFF event) and extended to the time when valve 106 begins to move at P3.

[0172] Once P3 is identified, the valve control system 100 will execute the VP4 update step 556, where VP4 will be set to VS, i.e., the last measured voltage. After the VP4 update step 556, the valve control system 100 will execute the P4 voltage waiting step 558.

[0173] During the P4 voltage wait step 558, control logic 126 will wait for one or more clock cycles and then sample VS. Once VS is sampled, VP4 increment decision 560 can be determined. If VS is higher than the previously set VP4, VP4 increment decision 560 will return a True value, and VP4 update step 556 will be re-executed.

[0174] If VS is lower than the previously set VP4, then VP4 increases decision 560 and can return a False value, and P4 and Ttc are determined to be Tnow-Tdc.

[0175] It has been found that the steps taken to identify P3, including VP4 update step 556, P4 voltage wait step 558, and VP4 increment decision 560, can together determine the local maximum value P4, which is localized during Tsc. P4 represents the time it takes for valve 108 to stop moving and complete its cycle. It has also been found that the identification of P4 allows for the calculation of Tsc, or the time for valve 106 to be fully closed, starting from S2 (control voltage 402 OFF event) and extending to the time when valve 106 stops moving at P4.

[0176] Once the IP4 decrease decision 544 returns a True value indicating a local maximum P4, or the VP4 increase decision 560 returns a False value indicating a local maximum P4, the valve control system 100 can execute parameter step 562. Expected thresholds, such as the threshold used in the IP3 exceeding threshold decision 536, can be used with the IP4 increase decision 542 and the IP4 decrease decision 544 to make the decision less sensitive to noise. However, these are not shown to avoid obfuscating the valve control system 100.

[0177] Steps: P3 waiting step 528, IP3 decrease decision 530, IP3 update step 532, IP3 exceeds threshold decision 536, IP4 update step 538, P4 waiting step 540, IP4 increase decision 542 and IP4 decrease decision 544 can be regarded as Tsc measurement or shutdown time measurement.

[0178] Parameter step 562 can provide variables Tso, Tdo, Tto, Tsc, Tdc, and Ttc. These parameters can be used to calculate the error in step 564 according to equation 6 above.

[0179] Once the error is calculated in error calculation step 564, the valve control system 100 can execute TON control step 566 according to the above equation 7.

[0180] TONCNT is the control voltage 402, which includes the Err offset of the adjustment time. This will compensate for the mismatch between the control voltage signal and the response of valve 106.

[0181] The control voltage 402 can provide regulation to control the time when valve 106 begins to open at P1, stops opening at P2, begins to close at P3, and stops closing at P4. Depending on the application, each of these peak values ​​can be controlled and calibrated in each open-close cycle of valve 106.

[0182] Once the new TON is calculated in the TON calculation control step 566, this value can be used to set the timing for the next S1 or control voltage 402ON event. The valve control system 100 will execute the wait in step S1 568, which will... Figure 5A The VON is initiated in step 504 because the valve control system is in Figure 5A Continue at 5A1.

[0183] The local maxima P1 and P3, and the local minima P2 and P4, can be understood as the peak values ​​during the ON-OFF control cycle of the control voltage 202 and the current 204. The first two peaks, P1 and P2, can divide the start and end of valve 106 movement during the open cycle and can also be used to determine the delay between the control voltage ON signal and the start of movement. Similarly, the second two peaks, P3 and P4, can divide the start and end of valve 106 movement during the close cycle and can also be used to determine the delay between the control voltage OFF signal and the start of movement.

[0184] Unexpectedly, it was discovered that the calculation error and the new error-based control voltage allow the valve control system 100 to operate the valve 106 with a high degree of timing accuracy, unaffected by heat, contamination, humidity, or other environmental factors that may alter the valve speed in practice. Instead, the valve control system 100 can be adjusted to account for these parameters during each cycle.

[0185] Furthermore, it has been found that the valve control system 100 can operate with high timing accuracy without being negatively affected by fluid viscosity, fluid purity, or other properties of the materials within the valve, which in practice can alter the valve's speed. Moreover, the valve control system 100 can operate with high accuracy even during valve aging or throughout the maintenance cycle, delaying maintenance because the valve will be continuously calibrated in each cycle as it ages or undergoes maintenance changes, whereas calibration is typically only performed during initial production.

[0186] The disclosed process cannot actually be executed in human thought. For example, the human mind is not capable of reading current and voltage, or determining the local maximum and minimum values ​​for each PWM cycle. Therefore, as a practical problem, these steps cannot be fully executed in the human mind.

[0187] The applicant respectfully proposes applying a control voltage to a coil, which is communicatively coupled to a movable mechanism, thereby generating a BEMF peak within the coil based on the moving movable mechanism; detecting the BEMF peak using a current sensor; determining a first timing for the BEMF peak; and adjusting the timing of subsequent cycles of the control voltage based on the first timing to improve valve control technology, since the timing of the control voltage can be adjusted in each cycle based on the actual response of the valve. This significantly improves the accuracy of the valve control system compared to previous solutions that calibrated the valve only once during manufacturing or installation.

[0188] Furthermore, this method requires manipulating computer data structures, including digitized current, voltage, and local maxima and minima, as well as the output of time-modified voltage commands. The element of identifying local maxima and minima reflects improvements in the functionality of the valve control system 100, particularly for electromagnetically driven valves.

[0189] Solutions that provide time-corrected control voltages based on the maximum and minimum values ​​of local currents are inherently rooted in valve control systems to overcome common valve timing errors.

[0190] Figure 3A , 3B The control flow control technology process and control logic 126, switch controller 120, drive switch 116, and solenoid 102 themselves are described in sections 5A and 5B. These inherently include or reflect the opening and closing times of valves and solenoid valves, as well as the corresponding technical characteristics of the triggering of these components. This disclosure and claims provide teachings, including instructions for addressing specific technical problems of valve timing inaccuracies and drift calibration through technical solutions such as digitizing current, identifying local maxima and minima, and providing time correction in each cycle of the PWM control signal.

[0191] One anticipated embodiment includes: a valve control system comprising: a coil; a movable mechanism communicatively coupled to the coil such that a back electromotive force (BEMF) peak is generated within the coil based on movement of the movable mechanism; a drive switch configured to apply a control voltage to the coil; a sensor configured to detect the BEMF peak; and control logic configured to: determine a first timing of the BEMF peak and adjust a second timing of a subsequent period of the control voltage based on the first timing.

[0192] In this system: the BEMF peak value represents the initial movement of the movable mechanism after a delay measured from the start of the control voltage. In this system: the BEMF peak value is measured based on a threshold to determine if a service action is required. In this system: the BEMF peak value is a second BEMF peak value based on the control voltage applied to the coil; the second BEMF peak value indicates the end of the movement of the movable mechanism.

[0193] In this system: the control logic is configured to adjust the second timing of the control voltage in subsequent cycles according to Equation 7. In this system: the control logic is configured to determine the BEMF peak value based on the current in the coil exceeding a threshold.

[0194] In this system: the drive switch is configured to turn off the control voltage of the coil; the sensor is configured to detect a second BEMF peak based on the control voltage turning off of the coil; and the control logic is configured to determine a third timing of the second BEMF peak and adjust the turn-off timing of subsequent cycles of the control voltage based on the third timing. In this system: the control logic is configured to determine the BEMF peak based on the voltage.

[0195] Another anticipated embodiment includes: a non-transient computer-readable medium usefully associated with a processor having instructions configured to: apply a control voltage to a coil communicatively coupled to a movable mechanism such that a BEMF peak is generated within the coil based on the movement of the movable mechanism; determine the BEMF peak and a first timing of the BEMF peak; and adjust a second timing of subsequent cycles of the control voltage based on the first timing.

[0196] Non-transient computer-readable device, wherein instructions are configured to: identify the initial movement of the movable mechanism based on the BEMF peak value after a delay measured from the start of the control voltage. Non-transient computer-readable device, wherein instructions are configured to: measure the BEMF peak value according to a threshold to determine whether a service action is required. The non-transient computer-readable device, wherein the instructions are configured to: identify the BEMF peak value as a second BEMF peak value based on the control voltage applied to the coil, the second BEMF peak value indicating the end of movement of the movable mechanism.

[0197] Non-transient computer-readable, wherein the instructions are configured to: adjust the second timing of the control voltage in subsequent cycles according to Equation 7. Non-transient computer-readable, wherein the instructions are configured to: determine the BEMF peak value based on the current in the coil exceeding a threshold.

[0198] The non-transient computer-readable device of claim 8, wherein the instructions are configured to: turn off the control voltage of the coil; detect a second back electromotive force (BEMF) peak based on the control voltage of the coil being turned off; determine a third timing for the second BEMF peak; and adjust the turn-off timing of subsequent cycles of the control voltage based on the third timing. The non-transient computer-readable device further includes instructions configured to: determine the BEMF peak based on the voltage.

[0199] Another anticipated embodiment includes: a method for controlling an operating valve system, comprising: applying a control voltage to a coil, the coil being communicatively coupled to a movable mechanism, thereby generating a BEMF peak value within the coil based on the movable mechanism; detecting the BEMF peak value with a sensor; determining a first timing of the BEMF peak value; and adjusting a second timing of subsequent cycles of the control voltage based on the first timing.

[0200] In this method: detecting the BEMF peak includes detecting the initial movement of the movable mechanism after a delay measured from the start of the control voltage. The method also includes: measuring the BEMF peak based on a threshold to determine whether a service action is required. In this method: detecting the BEMF peak includes detecting a second BEMF peak based on the control voltage applied to the coil, the second BEMF peak indicating the end of movement of the movable mechanism.

[0201] In this method: adjusting the second timing of subsequent cycles of the control voltage includes adjusting the second timing according to Equation 7. The method also includes: determining the BEMF peak value based on the current in the coil exceeding a threshold.

[0202] The method further includes: turning off the control voltage of the coil; detecting a second BEMF peak value based on the control voltage of the coil being turned off; determining a third timing for the second BEMF peak value; and adjusting the turn-off timing of subsequent cycles of the control voltage based on the third timing. The method for detecting the BEMF peak value includes detecting the BEMF peak value as a voltage.

[0203] Therefore, it has been discovered that valve control systems offer significant, previously unknown, and unavailable solutions, capabilities, and functionalities. The resulting configurations are simple, cost-effective, uncomplicated, highly versatile, accurate, sensitive, and efficient, and can be achieved by adapting known components to enable off-the-shelf, efficient, and economical manufacturing, application, and utilization.

[0204] In practical applications, debris accumulation, plant growth, and liquid solution crystallization can alter the quality of valve components, while delayed maintenance can change the surface roughness of these components. These environmental consequences can significantly impact the actual operation and timing of the valve.

[0205] When a valve is calibrated only once during manufacturing or implementation, these environmental consequences can drastically alter its operation, rendering it inaccurate. It has been found that events S1 and S2 can be shifted forward to account for delays Tdo and Tdc, as well as total shift times Tso and Tsc.

[0206] Taking these timeframes into account, the valve system can operate with very high precision, regardless of delayed maintenance, debris buildup, or other environmental factors. Furthermore, this solution requires no external sensors, relying solely on a current sensor and an ADC to detect and digitize the current or voltage passing through the solenoid.

[0207] Tdo, Tdc, Tto, and Ttc can also be used for diagnostic purposes. For example, an unexpectedly long Tdo may be a symptom of valve malfunction. Therefore, it is possible to determine the appropriate Tdo based on the following: Figure 1 A time threshold of 140 is used to measure Tdo, Tdc, Tto, and Ttc to determine maintenance or repair conditions.

[0208] While a valve control system has been described in conjunction with a specific optimal model, it should be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art based on the foregoing description. Therefore, it is intended to cover all alternatives, modifications, and variations that fall within the scope of the included claims. All matters described herein or illustrated in the figures should be interpreted in an illustrative and non-limiting sense.

Claims

1. A valve control system comprising: control logic configured to be coupled to a conductor and a movable mechanism such that a back electromotive force (BEMF) peak is generated within the conductor based on movement of the movable mechanism, the control logic further configured to: apply a control voltage to the conductor; detect a BEMF peak; determine a peak timing of the BEMF peak; and adjust a control voltage timing of the control voltage based on the peak timing.

2. The system of claim 1, wherein the control logic is configured to detect the BEMF peak as a current peak.

3. The system of claim 1, wherein the control logic is configured to detect the BEMF peak as a voltage peak.

4. The system of claim 1, wherein the control logic is configured to adjust the control voltage timing for a control voltage ON time, a control voltage OFF time, or both a control voltage ON time and a control voltage OFF time.

5. The system of claim 1, wherein the control logic is configured to determine whether a service action is required based on the BEMF peak.

6. The system of claim 1, wherein the control logic is configured to adjust the control voltage timing according to Equation 7.

7. The system of claim 1, wherein the control logic is configured to detect the BEMF peak as a start of motion or an end of motion of the movable mechanism.

8. A non-transitory computer readable medium in useful association with a processor having instructions configured to: apply a control voltage to a conductor; detect a back electromotive force (BEMF) peak generated within the conductor based on a movable mechanism moving; determine a peak timing of the BEMF peak; and adjust a control voltage timing of the control voltage based on the peak timing.

9. The non-transitory computer readable medium of claim 8, wherein the instructions are configured to detect the BEMF peak as a current peak.

10. The non-transitory computer readable medium of claim 8, wherein the instructions are configured to detect the BEMF peak as a voltage peak.

11. The non-transitory computer readable medium of claim 8, wherein the instructions are configured to adjust a control voltage ON time, a control voltage OFF time, or both a control voltage ON time and a control voltage OFF time.

12. The non-transitory computer readable medium of claim 8, wherein the instructions are configured to determine whether a service action is required based on the BEMF peak.

13. The non-transitory computer readable medium of claim 8, wherein the instructions are configured to adjust the control voltage timing according to Equation 7.

14. The non-transitory computer readable medium of claim 8, wherein the instructions are configured to detect the BEMF peak as a start of motion or an end of motion of the movable mechanism.

15. A method of operating a valve control system comprising: applying a control voltage to a conductor; detecting, by a mobile-based movable mechanism, a back electromotive force (BEMF) peak generated within the conductor; determining a peak timing of the BEMF peak; and adjusting a control voltage timing of the control voltage based on the peak timing.

16. The method of claim 15, wherein: detecting the BEMF peak includes detecting the BEMF peak as a current peak.

17. The method of claim 15, wherein: detecting the BEMF peak includes detecting the BEMF peak as a voltage peak.

18. The method of claim 15, wherein: adjusting the control voltage timing includes adjusting a control voltage ON time, a control voltage OFF time, or both a control voltage ON time and a control voltage OFF time.

19. The method of claim 15, further comprising: determining whether a service action is required based on the BEMF peak.

20. The method of claim 15, wherein: adjusting the control voltage timing includes adjusting a control voltage timing according to Equation 7.

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