Proportional valve active vibration reduction controller and control method thereof

Abstract

The invention discloses a proportional valve active vibration reduction controller and a control method thereof. The controller comprises an induction signal detection module, a drive current control module and a resonance induction coil arranged on a proportional valve, and the resonance induction coil is wound outside a valve element of the proportional valve and located on one side of a drive coil of the proportional valve; the induction signal detection module is connected with the resonant induction coil to obtain voltage, current and resistance of the resonant induction coil, so that magnetic flux change generated in the resonant induction coil when the valve core vibrates is detected; the driving current control module is connected with a proportional valve driving coil to obtain the voltage and resistance of the driving coil, and the driving current control module suppresses magnetic flux change by actively calculating and adjusting the current of the driving coil, so that the amplitude of a valve element is reduced. The structure required for vibration suppression is slightly changed, the vibration suppression effect is fast, the action range is wide, the vibration suppression circuit intervenes in work at the vibration starting stage of the proportional valve, and the influence caused by resonance can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of proportional valve vibration suppression, and relates to a proportional valve active vibration suppression controller and a control method thereof. Background Art

[0002] Proportional valve resonance is a common problem in the use of proportional valves. It is caused by the vortex generated by the valve port hitting the natural frequency of the proportional valve moving iron core when the fluid passes through the proportional valve and meets certain pressure and flow conditions, thus causing the proportional valve to resonate. Proportional valve resonance can cause problems such as flow loss of control, vibration and noise, and affect the stability of the system in which it is located.

[0003] The existing solutions to the resonance problem of proportional valves basically revolve around the resonance point. For example, the structure can be modified to change the resonance frequency of the valve core so that it does not overlap with the vortex generation frequency of the target usage scenario. Or the damping of the moving iron core can be increased to reduce the amplitude of the valve core, thereby reducing the impact of the valve core resonance. Alternatively, the operating pressure, flow rate and other conditions can be changed to avoid the resonance point of the valve core. The above solutions may require a long R&D verification cycle, or have different degrees of impact on the application scenarios and hysteresis characteristics of the proportional valve, or the vibration suppression solution has low versatility and obvious disadvantages. Summary of the invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention proposes an active vibration reduction controller for a proportional valve and a control method thereof. By detecting the rate of change of magnetic flux generated by the vibration of the valve core, the corresponding excitation current is actively increased or decreased in the driving coil of the proportional valve, thereby generating a force opposite to the vibration direction of the valve core, thereby achieving the effect of vibration suppression. The specific technical scheme is as follows:

[0005] A proportional valve active vibration reduction controller comprises: an induction signal detection module, a drive current control module, and a resonant induction coil arranged on the proportional valve, wherein the resonant induction coil is wound around the outside of the proportional valve core and is located on one side of the proportional valve drive coil; the induction signal detection module is connected to the resonant induction coil to obtain the voltage, current and resistance of the resonant induction coil, thereby detecting the change of magnetic flux in the resonant induction coil when the valve core vibrates; the drive current control module is connected to the proportional valve drive coil to obtain the drive coil voltage and resistance, and the drive current control module actively calculates and adjusts the drive coil current to suppress the change of magnetic flux, thereby reducing the valve core amplitude.

[0006] Furthermore, the induction signal detection module includes: an induction sampling resistor, an induction signal processing and acquisition circuit, an analog switch and a constant current source circuit. The resonant induction coil is connected to the induction sampling resistor and the constant current source circuit respectively through the analog switch; when the analog switch is switched to connect the constant current source circuit, the induction signal processing and acquisition circuit collects the voltage across the resonant induction coil, and then based on the current of the constant current source circuit as a constant value, the resonant induction coil resistance can be calculated by Ohm's law; when the analog switch is switched to connect the induction sampling resistor, the induction signal processing and acquisition circuit continuously collects the voltage across the induction sampling resistor to detect whether the voltage across the induction sampling resistor changes. When the driving coil current of the proportional valve is stable, if a voltage change occurs across the induction sampling resistor, it indicates that the valve core of the proportional valve resonates.

[0007] Furthermore, the induction signal processing and acquisition circuit includes: a first operational amplifier, a first analog-to-digital converter, and a microprocessor. One end of the analog switch and one end of the resonant induction coil are commonly connected to the positive input end of the first operational amplifier. The other end of the analog switch is switched to connect one end of the induction sampling resistor and the positive end of the constant current source circuit. The other end of the resonant induction coil, the other end of the induction sampling resistor, and the negative end of the constant current source circuit are commonly connected to the reverse input end of the first operational amplifier. The output end of the first operational amplifier is connected to the first analog-to-digital converter, and the first analog-to-digital converter interacts with the microprocessor signal.

[0008] Furthermore, the drive current control module includes: a current control circuit, a drive sampling resistor, a drive signal processing and acquisition circuit and a processor. The current control circuit is controlled by the processor and connected to output current to the proportional valve drive coil; the drive sampling resistor is connected in series with the proportional valve drive coil, and the sampling signal is output to the drive signal processing and acquisition circuit to obtain the drive coil current; the drive signal processing and acquisition circuit is also connected to the drive coil to obtain the drive coil voltage; the processor collects and processes the signal obtained by the drive signal processing and acquisition circuit, and uses the current control circuit to adjust the output current to change the drive coil current to suppress the change of magnetic flux.

[0009] Furthermore, the current control circuit includes: a driver and a MOS tube. The processor controls the MOS tube through the driver. The MOS tube is connected to the drive coil. The driver uses a high-resolution PWM signal to control the high-speed MOS tube to achieve continuous current control.

[0010] Furthermore, the drive signal processing and acquisition circuit includes: a second operational amplifier, a third operational amplifier and a second analog-to-digital converter, wherein the second operational amplifier is connected to the drive coil, and the third operational amplifier is connected to the drive sampling resistor. The two operational amplifiers amplify their respective acquired signals and input them into the second analog-to-digital converter, which is then sent to the processor via the second analog-to-digital converter.

[0011] A proportional valve active vibration reduction control method comprises the following steps:

[0012] S1, the controller performs initialization process after power-on;

[0013] S2. Obtain the current resistance value of the induction coil through the induction signal detection module, and then continue to read the driving current. When it is zero, update the resistance value of the induction coil;

[0014] S3, obtaining the initial resistance value of the driving coil through the driving current control module;

[0015] S4, receiving information from the host computer and determining the current output value required to drive the proportional valve;

[0016] S5, according to the set driving current value and the feedback signal of the driving sampling resistor, the constant current driving output is realized through PID adjustment;

[0017] S5, detect the voltage across the resonant induction coil. If there is no voltage, it is considered that the valve core is stable, and the resistance value of the drive coil is updated and then returns to S4;

[0018] If there is an induced voltage, proceed to the next step;

[0019] S6, read whether the current driving current changes. If it does, it is considered that the induced voltage of the induction coil is generated by the driving current, and the valve core does not resonate, and return to S4;

[0020] If the output drive current does not change and there is an induced voltage, it is considered that the valve core is resonating and the next step is entered;

[0021] S7. To prevent the magnetic flux from changing, the output current required for vibration suppression is calculated, the drive current is reset, and the process jumps to S5 to output the vibration suppression current.

[0022] Furthermore, the S7 is specifically:

[0023] The induction coil resistance is measured by the induction signal detection module as r, the current flowing through the induction coil is i, and the voltage is u;

[0024] When the proportional valve resonates, the air gap between the moving iron core and the stationary iron core changes, and the magnetic resistance R m At a certain moment, let the magnetic flux of the magnetic circuit be Φ1. According to Kirchhoff's law on the induction coil, we know that:

[0025]

[0026] The number of turns of the induction coil is n;

[0027] The drive coil resistance is measured by the drive current control module as R, and the proportional valve drive coil voltage is U;

[0028] In order to reduce the valve core amplitude, change the current I of the drive coil. At the same time, let the magnetic flux of the magnetic circuit be Φ2. According to Kirchhoff's law on the drive coil:

[0029]

[0030] The number of turns of the proportional valve drive coil is N;

[0031] In order to meet the suppression requirements, the magnetic flux of the magnetic circuit does not change. Combining formulas ① and ②, the driving coil current is:

[0032]

[0033] That is, when the processor controls the valve core current of the proportional valve and satisfies formula ③, the valve core is subjected to an electromagnetic force in the opposite direction of its vibration, and the resonance of the proportional valve is suppressed.

[0034] Beneficial effects of the present invention:

[0035] 1. The structural changes required for vibration suppression are relatively small. The present invention does not need to change the structure of the proportional valve body, but only needs to change the coil and the proportional valve driver to achieve vibration suppression, thereby reducing the time cost of vibration suppression work.

[0036] 2. The present invention has a certain degree of self-adaptation. For various types of proportional valves, the two key parameters of the induction coil resistance and the drive coil resistance can be measured automatically. The valve can be directly installed and used by manually inputting the number of turns of the drive coil and the induction coil.

[0037] 3. The vibration suppression takes effect quickly and has a wide range of action. The vibration suppression circuit intervenes in the proportional valve's vibration starting stage and can generate corresponding reverse forces according to different amplitudes and frequencies, effectively reducing the impact of resonance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic cross-sectional structure diagram of a resonant induction coil of this embodiment wound around the outside of a proportional valve core;

[0039] Figure 2 is a circuit connection diagram of the induction signal detection module of this embodiment;

[0040] Figure 3 is a circuit connection diagram of the drive current control module of this embodiment;

[0041] Figure 4 4 is a flow chart of the active vibration reduction control method of the proportional valve in this embodiment. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and technical effect of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0043] The embodiment of the present invention discloses an active vibration reduction controller for a proportional valve, comprising an induction signal detection module, a drive current control module, and a resonant induction coil arranged on the proportional valve.

[0044] like Figure 1 As shown, the resonant induction coil 1 is a metal coil wound around the outside of the proportional valve core and inside the magnetic circuit ring of the proportional valve. The material is preferably copper wire with a number of turns. The resonant induction coil 1 is located on one side of the proportional valve drive coil 2, and the two coils can be isolated by non-magnetic materials. When the valve core resonates, the magnetic flux in the resonant induction coil 1 changes, thereby generating an induced electromotive force. Among them, the magnetic circuit of the proportional valve passes through the resonant induction coil, so that the magnetic ring can fully sense the changes in the magnetic field of the magnetic circuit.

[0045] like Figure 2 As shown in the figure, the induction signal detection module includes an induction sampling resistor, an induction signal processing and acquisition circuit, an analog switch, and a constant current source circuit. The detection mode can be switched through the analog switch. In the resistance detection mode: the induction signal processing and acquisition circuit is connected to the induction coil and the constant current source circuit, and the resistance value of the induction coil body is detected when the valve core is stationary; in the current and voltage detection mode: the induction signal processing and acquisition circuit is connected to the induction coil and the induction sampling resistor to detect the induced current and voltage in the induction coil.

[0046] Among them, the induction signal processing and acquisition circuit includes a first operational amplifier, a first analog-to-digital converter, and a microprocessor. When the induction signal detection module is powered on and initialized, the drive coil is kept without power supply, and the analog switch is connected to the constant current source circuit, so that the constant current source circuit and the resonant induction coil are connected in series, and the voltage across the induction coil is collected. If the current of the constant current source circuit is known to be a constant value, the resistance value of the induction coil can be calculated by Ohm's law. When the induction signal detection module is working normally, the analog switch is connected to the induction sampling resistor, so that the induction coil and the induction sampling resistor are connected in series, and the first analog-to-digital converter continuously collects the voltage across the induction sampling resistor. When the current of the driving coil of the proportional valve is stable, if a voltage is generated across the induction sampling resistor, it means that the valve core of the proportional valve is resonant.

[0047] like Figure 3As shown, the drive current control module includes a current control circuit, a drive sampling resistor, a drive signal processing and acquisition circuit and a processor. The current control circuit is controlled by the processor and connected to output current to the proportional valve drive coil. This current should have the characteristics of high resolution and fast response, such as using a high-resolution PWM signal to control a high-speed MOS tube to achieve continuous current control. The drive sampling resistor is connected in series with the proportional valve drive coil, and the sampling signal is output to the drive signal processing and acquisition circuit to obtain the drive coil current. The drive signal processing and acquisition circuit is also connected to the drive coil to obtain the drive coil voltage. The drive coil resistance can be calculated by the voltage and current of the coil under a small current output. The processor collects and processes the signal obtained by the drive signal processing and acquisition circuit, and uses the current control circuit to adjust the output current to achieve the vibration suppression effect of the proportional valve.

[0048] The current control circuit includes a driver and a MOS tube, and the processor controls the MOS tube through the driver.

[0049] The drive signal processing and acquisition circuit includes two operational amplifiers and a second analog-to-digital converter, wherein the second operational amplifier is connected to the drive coil, and the third operational amplifier is connected to the drive sampling resistor. The two operational amplifiers amplify the signals obtained by each other and input them into the second analog-to-digital converter, which is then sent to the processor via the analog-to-digital converter.

[0050] It can be seen that the MOS tube, the driving coil, the driving sampling resistor, the third operational amplifier, the second analog-to-digital converter, the second analog-to-digital converter and the processor constitute a closed-loop system, which can control the duty cycle of the MOS tube through PID, and use the driving sampling resistor to feedback the voltage value to form an adjustable constant current driving circuit. When the driving current control module is powered on and initialized, the adjustable constant current driving circuit generates a constant current source that is less than the minimum starting current of the proportional valve. The voltage across the driving coil is collected through the second operational amplifier, and the initial resistance value of the driving coil can be calculated by Ohm's law. When the driving current control module is working normally, the voltage across the driving coil is continuously collected. When the resonant induction coil does not detect the induced voltage, the coil resistance can be updated immediately to compensate for the temperature drift of the coil resistance.

[0051] The signal processing and acquisition circuit described above can be calibrated to obtain a more accurate signal for use in calculations. The resistance values ​​of the induction coil and the drive coil can be acquired multiple times when the valve core is in a steady state to correct the resistance effect caused by temperature drift.

[0052] The process of the controller of the present invention processing the signal is as follows:

[0053] Through the production process, we know that the number of turns of the induction coil is n;

[0054] The induction coil resistance is measured by the induction signal detection module as r, the current flowing through the induction coil is i, and the voltage is u;

[0055] When the proportional valve resonates, the air gap between the moving iron core and the stationary iron core changes, and the magnetic resistance R m At a certain moment, let the magnetic flux of the magnetic circuit be Φ1. According to Kirchhoff's law on the induction coil, we know that:

[0056]

[0057] The number of turns N of the proportional valve drive coil is known;

[0058] The drive coil resistance is measured by the drive current control module as R, and the proportional valve drive coil voltage is U;

[0059] In order to reduce the valve core amplitude, change the current I of the drive coil. At the same time, let the magnetic flux of the magnetic circuit be Φ2. According to Kirchhoff's law on the drive coil:

[0060]

[0061] In order to meet the suppression requirements, the magnetic flux of the magnetic circuit does not change. Combining formulas ① and ②, the total current of the drive coil is:

[0062]

[0063] That is, when the processor controls the valve core current of the proportional valve and satisfies formula ③, the valve core is subjected to an electromagnetic force in the opposite direction of its vibration, and the resonance of the proportional valve is suppressed.

[0064] like Figure 4 As shown, the specific process of using the controller of the present invention to perform vibration reduction control on the proportional valve is as follows:

[0065] S1, the controller performs initialization process after power-on;

[0066] S2. Obtain the current resistance value of the induction coil through the induction signal detection module, and then continue to read the driving current. When it is zero, update the resistance value of the induction coil;

[0067] S3, obtaining the initial resistance value of the driving coil through the driving current control module;

[0068] S4, receiving information from the host computer and determining the current output value required to drive the proportional valve;

[0069] S5, according to the set driving current value and the feedback signal of the driving sampling resistor, the constant current driving output is realized through PID adjustment;

[0070] S5, detect the voltage across the resonant induction coil. If there is no voltage, it is considered that the valve core is stable, and the resistance value of the drive coil is updated and then returns to S4;

[0071] If there is an induced voltage, proceed to the next step;

[0072] S6, read whether the current driving current changes. If it does, it is considered that the induced voltage of the induction coil is generated by the driving current, and the valve core does not resonate, and return to S4;

[0073] If the driving current does not change and there is an induced voltage, it is considered that the valve core is resonating and the next step is entered;

[0074] S7, according to the formula Calculate the output current required for vibration suppression, reset the drive current, and jump to S5 to output the vibration suppression current.

[0075] The above description is only a preferred implementation case of the present invention and does not limit the present invention in any form. Although the implementation process of the present invention is described in detail above, for those familiar with the art, they can still modify the technical solutions recorded in the above examples, or replace some of the technical features therein with equivalents. All modifications, equivalent replacements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A proportional valve active vibration reduction controller, comprising: An induction signal detection module, a drive current control module, and a resonant induction coil arranged on a proportional valve, characterized in that the resonant induction coil is wound around the outside of the proportional valve core and is located on one side of the proportional valve drive coil; the induction signal detection module is connected to the resonant induction coil to obtain the voltage, current and resistance of the resonant induction coil, thereby detecting the change in magnetic flux in the resonant induction coil when the valve core vibrates; the drive current control module is connected to the proportional valve drive coil to obtain the drive coil voltage and resistance, and the drive current control module actively adjusts the drive coil current to suppress the change in magnetic flux, thereby reducing the valve core amplitude.

2. The proportional valve active vibration reduction controller according to claim 1, characterized in that: The induction signal detection module includes: an induction sampling resistor, an induction signal processing and acquisition circuit, an analog switch and a constant current source circuit. The resonant induction coil is connected to the induction sampling resistor and the constant current source circuit respectively through the analog switch. When the analog switch is switched to connect the constant current source circuit, the induction signal processing and acquisition circuit collects the voltage across the resonant induction coil, and then based on the current of the constant current source circuit as a constant value, the resonant induction coil resistance can be calculated by Ohm's law. When the analog switch is switched to connect the induction sampling resistor, the induction signal processing and acquisition circuit continuously collects the voltage across the induction sampling resistor to detect whether the voltage across the induction sampling resistor changes. When the driving coil current of the proportional valve is stable, if the voltage across the induction sampling resistor changes, it indicates that the valve core of the proportional valve resonates.

3. The proportional valve active vibration reduction controller according to claim 2, characterized in that: The induction signal processing and acquisition circuit includes: a first operational amplifier, a first analog-to-digital converter, and a microprocessor. One end of the analog switch and one end of the resonant induction coil are commonly connected to the positive input end of the first operational amplifier. The other end of the analog switch is switched to connect one end of the induction sampling resistor and the positive end of the constant current source circuit. The other end of the resonant induction coil, the other end of the induction sampling resistor, and the negative end of the constant current source circuit are commonly connected to the reverse input end of the first operational amplifier. The output end of the first operational amplifier is connected to the first analog-to-digital converter, and the first analog-to-digital converter interacts with the microprocessor signal.

4. The proportional valve active vibration reduction controller according to claim 2, characterized in that: The driving current control module comprises: a current control circuit, a driving sampling resistor, a driving signal processing and acquisition circuit and a processor; the current control circuit is controlled by the processor to output current to the proportional valve driving coil; The driving sampling resistor is connected in series with the driving coil, and the sampling signal is output to the driving signal processing and acquisition circuit to obtain the driving coil current; The drive signal processing and acquisition circuit is also connected to the drive coil to obtain the drive coil voltage; the processor collects and processes the signal obtained by the drive signal processing and acquisition circuit, and uses the current control circuit to adjust the output current to change the drive coil current to suppress the change of magnetic flux.

5. The proportional valve active vibration reduction controller according to claim 4, characterized in that: The current control circuit includes: a driver and a MOS tube. The processor controls the MOS tube through the driver. The MOS tube is connected to the drive coil. The driver uses a high-resolution PWM signal to control the high-speed MOS tube to achieve continuous current control.

6. The proportional valve active vibration reduction controller according to claim 4, characterized in that: The drive signal processing and acquisition circuit includes: a second operational amplifier, a third operational amplifier and a second analog-to-digital converter, wherein the second operational amplifier is connected to the drive coil, and the third operational amplifier is connected to the drive sampling resistor. The two operational amplifiers amplify the signals obtained by each other and input them into the second analog-to-digital converter, and then send them to the processor through the second analog-to-digital converter.

7. The control method of the proportional valve active vibration reduction controller according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, the controller performs initialization process after power-on; S2. Obtain the current resistance value of the induction coil through the induction signal detection module, and then continue to read the driving current. When it is zero, update the resistance value of the induction coil; S3, obtaining the initial resistance value of the driving coil through the driving current control module; S4, receiving information from the host computer and determining the current output value required to drive the proportional valve; S5, according to the set driving current value and the feedback signal of the driving sampling resistor, the constant current driving output is realized through PID adjustment; S5, detect the voltage across the resonant induction coil. If there is no voltage, it is considered that the valve core is stable, and the resistance value of the drive coil is updated and then returns to S4; If there is an induced voltage, proceed to the next step; S6, read whether the current driving current changes. If it does, it is considered that the induced voltage of the induction coil is generated by the driving current, and the valve core does not resonate, and return to S4; If the driving current does not change and there is an induced voltage, it is considered that the valve core is resonating and the next step is entered; S7. To prevent the magnetic flux from changing, the output current required for vibration suppression is calculated, the drive current is reset, and the process jumps to S5 to output the vibration suppression current.

8. The control method according to claim 7, characterized in that: The S7 is specifically: The induction coil resistance is measured by the induction signal detection module as r, the current flowing through the induction coil is i, and the voltage is u; When the proportional valve resonates, the air gap between the moving iron core and the stationary iron core changes, and the magnetic resistance R m changes; at a certain moment, let the magnetic flux of the magnetic circuit be Φ1, according to Kirchhoff's law on the induction coil: The number of turns of the induction coil is n; The drive coil resistance is measured by the drive current control module as R, and the proportional valve drive coil voltage is U; In order to reduce the valve core amplitude, change the current I of the drive coil. At the same time, let the magnetic flux of the magnetic circuit be Φ2. According to Kirchhoff's law on the drive coil: The number of turns of the proportional valve drive coil is N; In order to meet the suppression requirements, the magnetic flux of the magnetic circuit does not change. Combining formulas ① and ②, the driving coil current is: That is, when the processor controls the valve core current of the proportional valve and satisfies formula ③, the valve core is subjected to an electromagnetic force in the opposite direction of its vibration, and the resonance of the proportional valve is suppressed.

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