CN-121976994-A - Oil pressure stability monitoring system based on accurate regulation and control of fluid non-electric variables

CN121976994ACN 121976994 ACN121976994 ACN 121976994ACN-121976994-A

Abstract

The invention relates to the technical field of hydraulic pressure, and discloses an oil pressure stability monitoring system based on precise regulation and control of fluid non-electric variables, which comprises an acoustic parameter sensing unit, a fluid state resolving unit and a pressure regulation executing unit, wherein the acoustic parameter sensing unit acquires a medium ultrasonic echo signal to determine real-time acoustic impedance and sound Cheng Cuijian coefficients, the fluid state resolving unit utilizes the real-time acoustic impedance to identify cavitation distribution quantity, determines an instruction slope limit value according to the volume elastic modulus degradation quantity, the pressure regulation executing unit carries out dynamic limiting on a control instruction based on the instruction slope limit value, limits the executing mechanism to start transient displacement change rate, and utilizes a state correction factor to adjust the cut-off frequency of a low-pass filter.

Inventors

CAI CHUNHUA
YANG JIAN

Assignees

上海锐测电子科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260312

Claims (10)

1. An oil pressure stability monitoring system based on accurate regulation and control of fluid non-electric variables, which is characterized in that the system comprises: The acoustic parameter sensing unit is used for acquiring an ultrasonic echo signal of the fluid medium in the hydraulic circuit and determining the real-time acoustic impedance rate and the acoustic Cheng Cuijian coefficient of the fluid medium based on the ultrasonic echo signal; A fluid state resolving unit for identifying microscopic cavitation distribution quantity in the fluid medium by utilizing real-time acoustic impedance, and resolving an instruction slope limit value for restraining the action amplitude of the actuating mechanism in the pressure adjusting and actuating unit according to the fluid volume elastic modulus degradation quantity corresponding to the microscopic cavitation distribution quantity; The pressure regulating executing unit is used for receiving the pressure control instruction, and implementing dynamic amplitude limiting on the output slope of the pressure control instruction based on the instruction slope limit value so as to limit the transient displacement change rate of the executing mechanism in the opening direction, and meanwhile, the pressure regulating executing unit is also used for determining a state correction factor according to the sound Cheng Cuijian coefficient and the real-time acoustic impedance, and utilizing the state correction factor to adjust the cut-off frequency of the internal low-pass filter in real time so as to dynamically align the control bandwidth of the system with the inherent resonance frequency of the fluid medium.
2. The oil pressure stability monitoring system based on precise regulation and control of fluid non-electric variables according to claim 1, wherein the fluid state resolving unit is used for detecting deviation of real-time acoustic impedance relative to preset reference impedance, setting the command slope limit value to be a dynamic threshold value which is monotonically and positively related to the real-time acoustic impedance according to a mapping rule of the preset fluid elastic modulus and the acoustic impedance, and reducing transient response slope of a pressure control command by adjusting the command slope limit value under the working condition that gas content in a fluid medium is increased and the fluid rigidity is reduced.
3. The oil pressure stability monitoring system based on precise regulation and control of fluid non-electrical variables according to claim 1, wherein the acoustic parameter sensing unit comprises a high-frequency ultrasonic transduction module arranged at the upstream of a throttling part of a hydraulic circuit, the center frequency of the high-frequency ultrasonic transduction module is not lower than 10MHz, and the acoustic parameter sensing unit is used for transmitting ultrasonic pulses to the inside of a flow channel through the high-frequency ultrasonic transduction module and capturing ultrasonic echo signals generated by gas phase interface reflection inside a fluid medium.
4. The system for accurately regulating and controlling oil pressure stability according to claim 1, wherein the pressure regulating execution unit uses a state correction factor γ to cut off frequency of an internal low-pass filter Real-time remodeling is performed, which follows the following operational rules: , wherein, For the remodeled cut-off frequency, gamma is a state correction factor which is determined based on the ratio of the real-time acoustic impedance to the reference impedance and carries out nonlinear correction by combining with the acoustic Cheng Cuijian coefficient and is used for representing the comprehensive variation of the energy absorption characteristic and the physical rigidity of the fluid medium, A reference cut-off frequency preset for the system.
5. The oil pressure stability monitoring system based on precise regulation and control of fluid non-electrical variables according to claim 1, wherein the pressure regulation execution unit is further used for determining real-time dynamic viscosity of a fluid medium based on a sound Cheng Cuijian coefficient and determining starting feedforward compensation quantity for an execution mechanism according to the real-time dynamic viscosity, and the pressure regulation execution unit is used for superposing the starting feedforward compensation quantity into a pressure control instruction.
6. The oil pressure stability monitoring system based on precise regulation and control of fluid non-electrical variables according to claim 1, wherein the acoustic parameter sensing unit is used for determining real-time sound velocity according to flight time of an ultrasonic echo signal, and calculating real-time equivalent density of a fluid medium by combining the real-time sound velocity and the real-time acoustic impedance rate so as to correct an evaluation reference of fluid bulk modulus in the fluid state resolving unit.
7. The system of claim 1, wherein the pressure regulating and executing unit is provided with defensive control logic, and when the falling amplitude of the real-time acoustic impedance relative to the preset reference impedance exceeds a preset instability critical threshold, the pressure regulating and executing unit forcibly sets the output slope of the pressure control instruction to 0 so as to enable the executing mechanism to keep the current displacement state.
8. The oil pressure stability monitoring system based on fluid non-electrical variable precise regulation and control according to claim 1, wherein the high-frequency ultrasonic transduction module adopts a circumferential enveloping arrangement structure, and the acoustic parameter sensing unit extracts radial gradient parameters representing non-uniform distribution of physical properties of a fluid medium by acquiring ultrasonic echo signals at a plurality of different radial depths so as to adjust nonlinear control gain output by the fluid state calculating unit.
9. The system for monitoring the oil pressure stability based on the precise regulation and control of the fluid non-electric variable according to claim 1, further comprising a data storage unit for recording the evolution value of the real-time acoustic impedance rate along with the running time of the system and predicting the physical characteristic failure period of the fluid medium based on a preset degradation judgment rule.
10. The system for monitoring the oil pressure stability based on the precise regulation and control of the fluid non-electric variable according to claim 1, further comprising an early warning unit for outputting an alarm signal when the real-time acoustic impedance is lower than a preset safety limit value and driving the pressure regulation execution unit to switch to a low-response speed limiting mode.

Description

Oil pressure stability monitoring system based on accurate regulation and control of fluid non-electric variables Technical Field The invention relates to an oil pressure stability monitoring system based on accurate regulation and control of fluid non-electric variables, and belongs to the technical field of hydraulic pressure. Background When the hydraulic system is in a high-frequency dynamic response working condition, fluid is instantaneously sheared at a valve port and influenced by environmental temperature gradient, microscopic air pockets are generated in the fluid, and the microscopic air pockets cause nonlinear change of the volume elastic modulus of the fluid medium, and under the working condition, the transmission rigidity of the fluid medium is not constant and dynamic drift characteristics are presented. In addition to feedback limitation, control logic also has the defect of avoiding medium degradation instability, for example, chinese patent application No. CN213899489U discloses a breaking hammer hydraulic system, oil return back pressure is monitored through a pressure sensor, a switching valve is controlled to change direction when the back pressure exceeds a preset value, oil return bypasses a radiator to pass through an oil tank, in order to improve pressure following effect, technical means for improving sampling frequency of the pressure sensor or increasing response speed of an actuating mechanism are generally adopted, however, signals captured by the pressure sensor belong to the occurred pressure drop result, evolution of physical state in a medium occurs before pressure signal change, the simple improvement of the sampling frequency cannot eliminate physical hysteresis of a feedback signal, meanwhile, the increase of compensation gain leads to instantaneous increase of valve port flow velocity, reduces local static pressure of a throttling section, and when the local static pressure is lower than fluid saturation vapor pressure, secondary cavitation group burst is induced, the degradation degree of the fluid medium is aggravated by the adjustment mode, and high-frequency tremble is caused by the system. Therefore, how to construct a defense mechanism by using the physical state variable of the fluid and realize stable adjustment of oil pressure on the premise of not inducing secondary degradation of the medium becomes the technical problem to be solved by the invention. Disclosure of Invention In order to solve the problems in the background technology, the technical scheme of the invention is as follows, an oil pressure stability monitoring system based on accurate regulation and control of fluid non-electric variables, which comprises: The acoustic parameter sensing unit is used for acquiring an ultrasonic echo signal of the fluid medium in the hydraulic circuit and determining the real-time acoustic impedance rate and the acoustic Cheng Cuijian coefficient of the fluid medium based on the ultrasonic echo signal; A fluid state resolving unit for identifying microscopic cavitation distribution quantity in the fluid medium by utilizing real-time acoustic impedance, and resolving an instruction slope limit value for restraining the action amplitude of the actuating mechanism in the pressure adjusting and actuating unit according to the fluid volume elastic modulus degradation quantity corresponding to the microscopic cavitation distribution quantity; The pressure regulating executing unit is used for receiving the pressure control instruction, and implementing dynamic amplitude limiting on the output slope of the pressure control instruction based on the instruction slope limit value so as to limit the transient displacement change rate of the executing mechanism in the opening direction, and meanwhile, the pressure regulating executing unit is also used for determining a state correction factor according to the sound Cheng Cuijian coefficient and the real-time acoustic impedance, and utilizing the state correction factor to adjust the cut-off frequency of the internal low-pass filter in real time so as to dynamically align the control bandwidth of the system with the inherent resonance frequency of the fluid medium. Preferably, the fluid state resolving unit is used for detecting the deviation amount of the real-time acoustic impedance relative to the preset reference acoustic impedance, setting the instruction slope limit value as a dynamic threshold value which is monotonically and positively correlated with the real-time acoustic impedance according to the mapping rule of the preset fluid elastic modulus and the acoustic impedance, and reducing the transient response slope of the pressure control instruction by adjusting the instruction slope limit value under the working condition that the internal gas content of the fluid medium is increased and the fluid stiffness is reduced. Preferably, the acoustic parameter sensing unit comprises a high-frequency ultrasonic transductio