Pump control hydraulic pressure vibration suppression control method and system based on active volume regulation and control

Abstract

The invention provides a pump control hydraulic pressure vibration suppression control method and system based on active volume regulation and control, and relates to the technical field of hydraulic system vibration control. The control method comprises the steps that S1, a controller of a pump control hydraulic system is used for collecting pressure data in real time, and a current high-pressure side oil way is recognized; s2, target compensation flow is injected into a main oil way by adjusting a proportional reversing valve, and pump source pulsation is actively restrained; s3, determining a real-time pressure deviation value, comparing the real-time pressure deviation value with a preset pressure fluctuation threshold value, and controlling a feedback control loop; s4, a control signal superposition strategy is adopted to determine the valve element target resultant displacement of the proportional reversing valve, and the fluid flow is regulated and controlled; and S5, the pressure of the pump-controlled hydraulic system is kept within the target pressure setting range, and vibration of the pump-controlled hydraulic system is actively restrained. Pressure fluctuation is jointly restrained through a feed-forward-feedback composite control strategy and a cooperative structure of the proportional reversing valve energy accumulator, and the pressure stability and the anti-interference performance of the hydraulic system under the complex working condition are improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system vibration control technology, specifically to a pump-controlled hydraulic vibration control method and system based on active volume regulation. Background Technology

[0002] Vibration in pump-controlled hydraulic systems is a key issue restricting equipment performance improvement. In actual operation, the interaction of fluid pressure pulsations, mechanical inertia, and external load disturbances easily induces strong vibrations and noise in the system. This not only severely weakens the control accuracy and dynamic response quality of the hydraulic system but also accelerates fatigue damage to pipelines and hydraulic components, significantly shortening equipment lifespan. Therefore, how to effectively suppress vibration in pump-controlled hydraulic systems has become a crucial problem that urgently needs to be solved to ensure the stable operation of high-end equipment.

[0003] Vibration suppression is generally divided into active and passive types. Passive suppression technologies, such as accumulators and Helmholtz resonators, are simple in structure and reliable in operation, and are therefore widely used in conventional hydraulic systems with relatively stable operating conditions. However, the parameters of passive suppression are usually fixed, and once the system's operating conditions change, its natural frequency often fails to keep in line with the external excitation frequency, leading to a decrease in vibration reduction effect. In contrast, active suppression technology, by introducing sensors, controllers, and actuators, can generate a reverse force based on real-time vibration signals, and is considered an effective way to solve complex vibration problems. However, traditional active control schemes often face problems such as complex system structure, high external energy consumption, high cost, and insufficient robustness of control algorithms, and still have certain limitations in practical engineering applications.

[0004] To address the aforementioned issues, existing technologies employ an integrated active-passive control system for hydraulic pump fluid pressure pulsation. This system uses a passive device to handle high-frequency pulsations and multiple servo valves and a supplementary pump to smooth out low-frequency pulsations, achieving full-frequency domain vibration suppression and source vibration control. However, this system is complex, involving multiple gate valve switching and an additional supplementary pump, resulting in high energy consumption, slow response, and discrete switching issues. Another existing technology, an active suppression method for hydraulic pipeline fluid pulsation based on the bilateral overflow principle, uses a passive device to filter out high-frequency pulsations and multiple servo valves in conjunction with a supplementary pump to smooth out low-frequency pulsations, achieving full-frequency domain vibration reduction and source vibration control. However, this method is complex, relying on multiple gate valve switching and an external supplementary pump, resulting in high energy consumption, slow response, and discrete control. The examples described suffer from cumbersome system structures, low energy utilization, and slow response speeds. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention aims to provide a pump-controlled hydraulic system vibration control method and system based on active volume regulation. This method constructs a feedforward-feedback composite control strategy by combining feedforward control based on a pump source flow pulsation model and feedback control based on pressure deviation. The feedforward stage actively predicts and counteracts pressure fluctuations caused by pump source pulsation, while the feedback stage corrects unmodeled disturbances or model errors, achieving a synergistic effect of prediction and correction. Active volume control is executed through the collaborative structure of a proportional directional valve and a second accumulator. Using the continuous displacement adjustment of the proportional directional valve as a carrier, the flow rate of oil flowing into or out of the second accumulator is dynamically adjusted, changing the gas volume within the second accumulator, suppressing pressure fluctuations in the hydraulic system, improving the accuracy and response speed of pressure control, and thus enhancing the pressure stability and anti-interference performance of the hydraulic system under complex operating conditions.

[0006] Specifically, on the one hand, the present invention provides a pump-controlled hydraulic vibration control method based on active volume regulation, which includes: S1: The controller of the pump-controlled hydraulic system collects the pressure data measured by the first pressure sensor in real time. Pressure data measured by the second pressure sensor The current high-pressure side oil circuit is identified by comparing the pressure difference. S2: Acquire the rotation angle and speed signals from the encoder of the servo motor of the bidirectional fixed displacement hydraulic pump; determine the instantaneous theoretical flow rate output by the pump source based on the flow pulsation model of the bidirectional fixed displacement hydraulic pump. Inject the target compensation flow into the main oil circuit by adjusting the proportional directional valve. Used to offset theoretical pressure fluctuations; to solve for the feedforward valve core reference displacement required by the proportional directional valve. Based on the current high-pressure side oil circuit identified in step S1, directional adaptation is performed so that the direction of feedforward control always corresponds to the pressure side to be maintained, thereby actively suppressing pump source pulsation. S3: Use the controller of the pump-controlled hydraulic system to obtain the actual pressure signal of the current high-pressure side oil circuit identified in step S1, and compare it with the preset target pressure signal in real time to determine the real-time pressure deviation value. Monitor real-time pressure deviation values The absolute value, and compared with the preset pressure fluctuation threshold. The comparison is made to determine whether to activate the feedback control loop; S4: Obtain the judgment result of step S3. When the feedback control loop is triggered, the real-time pressure deviation value will be... As input variables, the feedback control correction is determined using a PID algorithm. Simultaneously, the reference displacement of the feedforward valve core determined in step S2 is obtained. Based on the displacement-gain characteristics of the proportional directional valve, the reference displacement of the feedforward valve core is... As the corresponding feedforward reference drive current A control signal superposition strategy is adopted to superimpose the feedforward reference drive current. With feedback regulation current Linear superposition is performed to generate a composite drive current signal. The target composite displacement of the valve core of the proportional directional valve is obtained. To regulate fluid flow; S5: Based on the current high-pressure side oil circuit identified in step S1, map the main valve core reference displacement command to the operating direction and port status of the proportional directional valve; based on the valve core target composite displacement obtained in step S4... This maintains the pressure of the pump-controlled hydraulic system within the target pressure setting range.

[0007] Preferably, identifying the current high-pressure side oil circuit in step S1 specifically includes: when When the first pressure sensor is located, it is determined that the oil circuit is on the high-pressure side and the condition is set to positive. when When the second pressure sensor is located, it is determined that the oil circuit is on the high-pressure side, and the reverse operating condition is set. The high-pressure side oil circuit identification logic runs continuously, providing real-time directional information for the bidirectional pressure control of the pump-controlled hydraulic system.

[0008] Preferably, step S2 specifically includes: S21: Based on the instantaneous theoretical flow rate of the bidirectional fixed displacement hydraulic pump source. Relationship with rotation angle and angular velocity; hydraulic pump discharge period function Expanding to Fourier series form, and substituting the instantaneous theoretical flow rate of the hydraulic pump source... In the process, the flow pulsation model of the bidirectional fixed displacement hydraulic pump is obtained, and the flow rate of the bidirectional fixed displacement hydraulic pump is output. ; S22: In the complex frequency domain, through the hydraulic impedance of the pump-controlled hydraulic system Describing the theoretical pressure fluctuation components With the flow pulsation of the bidirectional fixed displacement hydraulic pump source Relationship; inject the target compensation flow into the main oil circuit by adjusting the proportional directional valve. To offset theoretical pressure fluctuations; S23: Determine the feedforward valve spool reference displacement required for the proportional directional valve. Based on the displacement-gain mapping formula of the proportional directional valve, the conversion relationship between valve core displacement and drive current, and the relationship between drive current and compensation flow are determined; the feedforward flow demand corresponding to the theoretical pressure fluctuation component is converted into the feedforward reference drive current.

[0009] Preferably, the bidirectional fixed displacement hydraulic pump flow rate output in step S21 is... for: ; in, This refers to the flow rate of a bidirectional fixed displacement hydraulic pump. This refers to the shaft rotation angle of a bidirectional fixed displacement hydraulic pump. This refers to the angular velocity of the shaft of a bidirectional quantitative hydraulic pump. The zeroth harmonic coefficient; This refers to the average flow rate output by a bidirectional fixed displacement hydraulic pump. For the first The amplitude coefficient of the first harmonic; m is the harmonic order; For the first The initial phase of the first harmonic; The spatial frequency of the pulsating fundamental frequency; It is a sine function; The symbol for infinity; This refers to the flow pulsation component output by the bidirectional fixed displacement hydraulic pump.

[0010] Preferably, in step S22, the target compensation flow rate is injected into the main oil circuit by adjusting the proportional directional valve. The specific methods to offset theoretical pressure fluctuations are as follows: ; in, for The flow rate through the proportional directional valve at any given time; For flow coefficient; The valve orifice area gradient; for The reference displacement of the feedforward valve core at any given moment; The density of the oil; for The pressure of the main oil circuit at the load end at any given time; for The pressure inside the accumulator at any given moment; For flow direction sign function; This is a time parameter.

[0011] Preferably, the feedforward reference drive current obtained in step S23 is: ; in, for The feedforward reference drive current of the proportional directional valve at any given time; for The target compensation flow rate of the main oil circuit at any given time; This is the displacement-current gain coefficient of the proportional directional valve.

[0012] Preferably, in step S3, the real-time pressure deviation value is monitored. The absolute value, and compared with the preset pressure fluctuation threshold. A comparison is made to determine whether to activate the feedback control loop, specifically: Determine the real-time pressure deviation value Is the absolute value greater than the preset pressure fluctuation threshold? If the real-time pressure deviation value The absolute value is less than or equal to the preset pressure fluctuation threshold. If the current pressure fluctuation only needs to trigger the feedforward control loop to maintain the current feedforward control output, then the current pressure fluctuation should be considered as a separate event. The absolute value is greater than the preset pressure fluctuation threshold. If a disturbance or model error is detected that is not covered by the model prediction, a feedback control loop is triggered to stabilize the pressure at the target value.

[0013] Preferably, the target composite displacement of the valve core of the proportional directional valve is obtained in step S4. Specifically ; ; ; in, for The target composite displacement of the valve core of the proportional directional valve at any given time; It is a composite drive current signal; for The reference displacement of the feedforward valve core of the proportional directional valve at any given moment; For feedback regulation of current; The conversion coefficient from control quantity to drive current; for The amount of feedback control correction at any given time.

[0014] Preferably, in step S5, the pressure of the pump-controlled hydraulic system is maintained within the target pressure setting range. Specifically, this is achieved by using the active change rate of the gas volume of the second accumulator to counteract disturbances in the pump source and load. ; in, for Total compensation flow at any given moment; for The pump source output flow rate at any given time; for Traffic consumption at any given moment; This refers to the total effective volume of the pump-controlled hydraulic system. This refers to the effective bulk elastic modulus of the oil. This represents the leakage coefficient of the pump-controlled hydraulic system.

[0015] On the other hand, the present invention provides a pump-controlled hydraulic system based on an active volume regulation-based pump-controlled hydraulic vibration control method, comprising: a servo motor, a coupling, a bidirectional fixed-displacement hydraulic pump, a first check valve, a first relief valve, a second relief valve, a filter, a replenishing pressure relay, a temperature sensor, a first flow meter, a second flow meter, a first pressure sensor, a second pressure sensor, a hydraulic cylinder, a left-side load, a right-side load, a first accumulator, a controller, and a high-pressure cooler; a proportional directional valve and a second accumulator; the cooperative structure of the proportional directional valve and the second accumulator performs active volume control, using the continuous displacement adjustment of the proportional directional valve as a carrier to dynamically adjust the flow rate of oil flowing into or out of the second accumulator, thereby changing the gas volume in the second accumulator and performing pump-controlled hydraulic vibration control; the second accumulator is connected to the first oil circuit and the second oil circuit of the pump-controlled hydraulic system through the proportional directional valve, respectively.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention performs active volume control through the cooperative structure of the proportional directional valve and the second accumulator. The continuous displacement adjustment of the proportional directional valve is used as the carrier to dynamically adjust the flow rate of oil flowing into or out of the second accumulator, thereby changing the gas volume in the second accumulator. This solves the limitation of pressure fluctuation suppression in traditional hydraulic systems relying on passive buffering or fixed parameter adjustment, and improves the accuracy and response speed of pressure control.

[0017] (2) This invention combines feedforward control based on pump source flow pulsation model and feedback control based on pressure deviation to construct a feedforward-feedback composite control strategy. The feedforward link actively predicts and cancels the pressure fluctuation caused by pump source pulsation, and the feedback link corrects unmodeled disturbances or model errors, realizing the synergistic effect of prediction and correction, and improving the pressure stability and anti-interference performance of hydraulic system under complex working conditions.

[0018] (3) The present invention dynamically identifies the working condition of the high-pressure side by comparing the real-time difference between the pressure sensors on both sides, so that the direction of the feedforward command and the feedback correction is always matched with the current high-pressure side, realizing the real-time adaptability of bidirectional pressure control, solving the problem of control failure caused by directional misalignment when the traditional control strategy switches working conditions, and enhancing the working condition adaptability and control continuity of the hydraulic system. Attached Figure Description

[0019] Figure 1 This is a control block diagram of the pump-controlled hydraulic vibration control method based on active volume regulation of the present invention; Figure 2 This is a control flowchart of the pump-controlled hydraulic system based on active volume regulation according to the present invention; Figure 3 This is a schematic diagram of the hydraulic system based on active volume control according to the present invention; Figure 4 This is a flow response diagram of the system under feedforward control in an embodiment of the present invention; Figure 5 This is a comparison diagram of the high-pressure side pressure pulsation suppression effects under passive control and composite control in an embodiment of the present invention.

[0020] Key reference numerals: 1. Servo motor; 2. Coupling; 3. Bidirectional quantitative hydraulic pump; 4. First check valve; 5. Second check valve; 6. First relief valve; 7. Second relief valve; 8. Filter; 9. Oil replenishment pressure relay; 10. Temperature sensor; 11. Proportional directional valve; 12. First flow meter; 13. Second flow meter; 14. First pressure sensor; 15. Second pressure sensor; 16. Hydraulic cylinder; 17. Left-side load; 18. Right-side load; 19. First accumulator; 20. Second accumulator; 21. Controller; 22. High-pressure cooler. Detailed Implementation

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] This invention proposes a pump-controlled hydraulic vibration control method based on active volume regulation, such as... Figure 1 As shown, the controller of the pump-controlled hydraulic system collects pressure data in real time to identify the current high-pressure side oil circuit; it injects the target compensation flow into the main oil circuit by adjusting the proportional directional valve to actively suppress pump source pulsation; it determines the real-time pressure deviation value and compares it with the preset pressure fluctuation threshold to control the feedback control loop; it uses a control signal superposition strategy to determine the target composite displacement of the valve core of the proportional directional valve and regulate the fluid flow; it maintains the pressure of the pump-controlled hydraulic system within the target setting range to actively suppress the vibration of the pump-controlled hydraulic system; specifically, it includes the following steps: Step S1: Use the controller of the pump-controlled hydraulic system to collect the pressure data measured by the first pressure sensor in real time. Pressure data measured by the second pressure sensor The current high-pressure side oil circuit is identified by comparing the pressure difference, specifically: when When the first pressure sensor is located, it is determined that the oil circuit is on the high-pressure side and set to the positive operating condition.

[0023] when When the second pressure sensor is located, it is determined that the oil circuit on the high-pressure side is the one where the oil circuit is located, and the reverse operating condition is set.

[0024] In this embodiment, the values ​​are P1=10.15MPa and P2=9.85MPa. It is determined that the side where the first pressure sensor is located at this moment is the high-pressure side oil circuit, and it is set to the positive operating condition.

[0025] The aforementioned high-pressure side oil circuit identification logic continues to operate, providing real-time directional information for the bidirectional pressure control of the pump-controlled hydraulic system.

[0026] Step S2: Use the controller of the pump-controlled hydraulic system to acquire the rotation angle and speed signals from the encoder of the bidirectional fixed displacement hydraulic pump's servo motor as feedforward input variables. Based on a preset bidirectional fixed displacement hydraulic pump flow pulsation model, calculate the instantaneous theoretical flow rate output by the pump source in real time according to the rotation angle and speed. By utilizing fluid impedance transformation relationships, the theoretical pressure fluctuation component caused by the pulsation of the bidirectional quantitative hydraulic pump source flow at the load end is derived. This theoretical pressure fluctuation component specifically refers to the alternating change portion of the total pressure signal at the load end relative to the target steady-state pressure. The controller maps the theoretical pressure fluctuation component to a feedforward valve core reference displacement command and, based on the current high-pressure side oil circuit identified in step S1, adapts the sign of this command in direction, ensuring that the direction of the feedforward control action always corresponds to the pressure side to be maintained, thus actively suppressing the pump source pulsation. Figure 4 The diagram shown is a system flow response diagram under feedforward control in an embodiment of the present invention; specifically, it includes the following steps: Step S21: Based on the instantaneous theoretical flow rate of the bidirectional fixed displacement hydraulic pump source. The relationship between rotation angle and angular velocity is used to determine the instantaneous theoretical flow rate of the pump source of a bidirectional fixed displacement hydraulic pump of any positive displacement type. Expressed as the angular velocity of the shaft of a bidirectional fixed displacement hydraulic pump =157.08 rad / s and the derivative of the instantaneous discharge volume with respect to the angle of rotation, as shown in the following formula: ; in, for The instantaneous theoretical flow rate of the bidirectional quantitative hydraulic pump source at any given moment; for The angular velocity of the bidirectional quantitative hydraulic pump shaft at time t, in this embodiment, is taken as _____. =157.08 rad / s; To adjust the rotation angle of the bidirectional fixed displacement hydraulic pump shaft The changing geometric volume function of the drainage chamber, in this embodiment, is taken as: = 28 cm 3 / rev; It is a hydraulic pump discharge period function, determined by the geometry of the bidirectional fixed displacement hydraulic pump, and reflects the discharge performance of the bidirectional fixed displacement hydraulic pump under a unit rotation angle. This refers to the shaft rotation angle of a bidirectional fixed displacement hydraulic pump. For time parameters; The derivative of the geometric volume function of the drainage chamber; This is the derivative of the shaft rotation angle of the bidirectional fixed displacement hydraulic pump.

[0027] Due to the periodic characteristics of the hydraulic pump discharge in the geometry of the bidirectional fixed displacement hydraulic pump, the hydraulic pump discharge periodic function... The rotation angle corresponding to the fundamental period is The hydraulic pump discharge period function Expanded into a Fourier series, it is as follows: ; in, The zero harmonic coefficient represents the average geometric displacement coefficient of the hydraulic pump, and is numerically equal to the displacement per revolution of the hydraulic pump divided by... ,Right now m is the harmonic order. ; The first amplitude coefficient of the mth harmonic is determined by the specific geometry of the bidirectional quantitative hydraulic pump. The second amplitude coefficient of the mth harmonic is determined by the specific geometry of the bidirectional quantitative hydraulic pump. The rotation angle corresponding to the fundamental period; The fundamental angular frequency coefficient; It is a sine function; It is a cosine function; The symbol for infinity; The displacement per revolution of the hydraulic pump is given in the example. = 28 cm 3 / rev; This is the parameter for pi.

[0028] In specific implementation cases: hydraulic pump discharge periodic function It mainly affects the fundamental frequency, harmonic order m=1, and initial phase. =0, , The case where =0; determined by the hydraulic pump's discharge period function. The expanded Fourier series form is: = =28×10 -6 / 2 The instantaneous theoretical flow rate of the hydraulic pump source The calculation formula is as follows =157.08×(28×10 -6 / 2 =42 L / min.

[0029] The above hydraulic pump discharge period function Substituting the expanded Fourier series form into the instantaneous theoretical flow rate of the hydraulic pump source The calculation formula yields the complete expression for the flow pulsation model of a bidirectional fixed-displacement hydraulic pump; the flow pulsation of the hydraulic pump calculated from the model is expressed as the sum of the average flow rate and the flow pulsation components, specifically: ; in, This refers to the flow rate of a bidirectional fixed displacement hydraulic pump. This refers to the angular velocity of the shaft of a bidirectional quantitative hydraulic pump. The average flow rate output by the bidirectional fixed displacement hydraulic pump, and the angular velocity. The relationship is linear; This refers to the flow pulsation component output by the bidirectional fixed displacement hydraulic pump. For the first The amplitude coefficient of the first harmonic. ; For the first The initial phase of the first harmonic; It is the spatial frequency of the pulsating fundamental frequency.

[0030] In the above formula This refers to the flow pulsation component output by a bidirectional fixed displacement hydraulic pump. The flow pulsation component is equal to... m=1; In this implementation case, =9, C1=0.45cm 3 / rad, flow pulsation component = 157.08 × 0.45 × 10 -6 ×sin(9× / 6)=0.495L / min; This gives the instantaneous theoretical flow rate. =42.495L / min.

[0031] Step S22: In the complex frequency domain, the theoretical pressure fluctuation component With the flow pulsation of the bidirectional fixed displacement hydraulic pump source The relationship between the hydraulic resistance of the pump-controlled hydraulic system and the hydraulic resistance The relationship between pressure fluctuation components and flow pulsation is described as follows: ; in, For the theoretical pressure fluctuation component, in the example =1.2 MPa·min / L×0.495L / min=0.594mpa; The equivalent hydraulic resistance of the pump-controlled hydraulic system is given in the embodiment. =1.2 MPa·min / L; For bidirectional quantitative hydraulic pump source flow pulsation in the complex frequency domain; This is a symbol for the complex frequency domain.

[0032] According to fluid transport theory, pressure fluctuations at the load end of the hydraulic pump are caused by flow pulsations under the influence of the pump-controlled hydraulic system impedance; to compensate for... Theoretical pressure fluctuation component at time t. It is necessary to inject a target compensation flow with equal amplitude but opposite phase into the main oil circuit. The compensation flow rate required to offset the theoretical pressure fluctuation component is as follows: ; in, for The target compensation flow rate of the main oil circuit at any given time is taken as a value in the example. =-0.495L / min.

[0033] The negative sign in the above formula indicates that the direction of the compensating flow is opposite to the direction of the interfering flow that causes pressure fluctuations, and is used to generate a cancellation effect.

[0034] Main oil circuit target compensation flow This needs to be achieved by adjusting the valve opening of the proportional directional valve. Based on Bernoulli's flow equation for the throttling orifice, the flow rate and valve core reference displacement of the proportional directional valve are determined. and valve port pressure difference =10.15-9.5=0.65MPa. The expression combining the compensation flow rate with the proportional directional valve is as follows: ; in, for The flow rate through the proportional directional valve at any given time; The value is the flow coefficient, which is 0.65 in this example. The valve port area gradient is 18.85 mm in this embodiment; The density of the oil; for The pressure of the main oil circuit at the load end at any given time; for The pressure inside the accumulator at any given moment; This is a flow direction sign function used to characterize the direction of flow. for The reference displacement of the feedforward valve core at any given time.

[0035] Step S23: Based on the flow-opening characteristic equation, calculate the target compensation flow rate of the main oil circuit. Substitute the values ​​and solve for the required feedforward valve core reference displacement of the proportional directional valve. This reference displacement characterizes the physical position that the valve core should reach to generate the target compensation flow. Combining the required displacement of the proportional directional valve core with the compensation flow, the calculation formula is as follows: ; in, for The reference displacement of the feedforward valve core of the proportional directional valve at any given time.

[0036] The electromagnetic actuator of a proportional directional valve has the characteristic of converting input current into valve spool driving force and displacement. Under operating conditions where the dynamic response bandwidth meets the requirements, the feedforward valve spool reference displacement of the proportional directional valve... With feedforward reference drive current Given a linear proportional relationship, the displacement-gain mapping formula for the proportional directional valve is obtained, and the conversion relationship between valve core displacement and drive current is determined as follows: ; in, The displacement-current gain coefficient of the proportional directional valve is taken as 0.5 mm / mA in this embodiment. for The feedforward reference drive current of the proportional directional valve at any given time.

[0037] By combining the formula for calculating the feedforward valve spool reference displacement of the proportional directional valve with the displacement-gain mapping relationship, and eliminating the intermediate variable valve spool reference displacement, the feedforward reference drive current can be directly calculated from the target compensation flow rate. The expression for determining the relationship between the drive current and the compensation flow rate is as follows: ; in, The density of the oil is 850 kg / m³ in this example. 3 .

[0038] In the embodiments, the theoretical pressure fluctuation component is included in the calculation. Unit conversion: -0.495 L / min = -0.495 / 60000 m 3 / s; The calculated result of the feedforward reference drive current of the proportional directional valve is: ; The negative sign in the above formula indicates that the direction of the current is opposite to the direction of the flow rate that generates pressure fluctuations.

[0039] Using the above formula, the controller converts the feedforward flow demand corresponding to the theoretical pressure fluctuation component into a direct output electrical signal, namely the feedforward reference drive current.

[0040] Step S3: Use the controller of the pump-controlled hydraulic system to acquire the actual pressure signal on the high-pressure side identified in step S1, and compare it with the preset target pressure signal in real time to determine the real-time pressure deviation value. Specifically: The controller of the pump-controlled hydraulic system calculates the real-time pressure deviation between the measured high-pressure side pressure value and the target set value. for: ; in, The target pressure value preset for the pump-controlled hydraulic system; for The pressure of the main oil circuit at the load end at any given time; The difference between the measured high-pressure side pressure and the target setpoint. Real-time pressure deviation value at any given moment.

[0041] Monitor real-time pressure deviation value The absolute value, and compared with the preset pressure fluctuation threshold. A comparison is made to determine whether to activate the feedback control loop. The decision logic formula is expressed as follows: ; in, The preset pressure fluctuation threshold; Real-time pressure deviation value The absolute value of.

[0042] When the above inequality holds true, it is determined that the current pressure fluctuation exceeds the feedforward control performance range, and the feedback control loop is triggered; when the above inequality does not hold true, it is determined that the current pressure fluctuation is within the allowable error range, and the feedback control loop is not triggered.

[0043] Preset pressure fluctuation threshold It is a key parameter for defining the feedforward control accuracy and the disturbance tolerance of the pump-controlled hydraulic system. Its value is determined based on the allowable relative pressure control accuracy index of the pump-controlled hydraulic system, specifically: ; in, The preset relative error coefficient for pressure control in a pump-controlled hydraulic system characterizes the proportion of the pump-controlled hydraulic system's tolerance to pressure fluctuations relative to the target pressure.

[0044] The target pressure in the above formula =10 MPa, allowable error coefficient The calculated pressure fluctuation threshold is 1%. The value is 0.1 MPa.

[0045] A pressure fluctuation threshold is preset in the controller to define the accuracy range of the feedforward control and the tolerance of disturbances in the pump-controlled hydraulic system, and to continuously judge the real-time pressure deviation value. Is the absolute value greater than the preset pressure fluctuation threshold? Specifically, if the real-time pressure deviation value The absolute value is less than or equal to the preset pressure fluctuation threshold. If the current pressure fluctuation only needs to trigger the feedforward control loop to maintain the current feedforward control output, then it is determined that the current pressure fluctuation only needs to trigger the feedforward control loop. If the real-time pressure deviation value... The absolute value is greater than the preset pressure fluctuation threshold. If a disturbance or model error is detected that is not covered by the model prediction, a feedback control loop is triggered to stabilize the pressure at the target value.

[0046] In specific implementation cases: ; This indicates that the pressure deviation exceeds the threshold, triggering the feedback control loop.

[0047] Step S4: Obtain the judgment result from step S3. When the feedback control loop is triggered, the controller will display the real-time pressure deviation value. As the input variable of the discrete PID control algorithm, the feedback control correction amount is determined by the PID algorithm. Simultaneously, the feedforward valve spool reference displacement determined in step S2 is obtained. Based on the displacement-gain characteristics of the proportional directional valve, the feedforward valve spool reference displacement is converted into the corresponding feedforward reference drive current. A control signal superposition strategy is adopted to linearly superimpose the feedforward reference drive current and the feedback adjustment current to generate a composite drive current signal. Since the response characteristics of the proportional directional valve conform to the principle of linear superposition, the composite drive current is physically equivalent to the valve spool first responding to the feedforward reference current to reach the reference position, and then responding to the feedback adjustment current for displacement correction. The controller outputs the composite drive current signal to the three-position four-way proportional valve amplifier after signal conditioning and digital-to-analog conversion, driving the valve spool of the proportional directional valve to generate a target composite displacement corresponding to the composite drive current. This allows the valve spool to be further fine-tuned by feedback control based on the reference opening established by the feedforward, such as... Figure 2 The diagram shown is a control flowchart of the pump-controlled hydraulic system based on active volume regulation according to the present invention; specifically, it includes the following steps: Using the pressure deviation calculated in real time in step S3 as input, and employing a preset discrete digital PID control algorithm, after activating the feedback loop, the calculated feedback control correction is as follows: ; in, for The amount of feedback control correction at any given moment; This is the proportional gain coefficient, which is set to 0.5 mA / mpa in this example. This is the integral gain coefficient, which is set to 0.1 mA / mpa in this example. This is the differential gain coefficient, which is set to 0.05 mA / mpa in this example. The control cycle of the pump-controlled hydraulic system is 1ms in this embodiment; Let be the real-time pressure deviation at time j; This is the time index variable for cumulative summation; for The real-time pressure deviation at time -1 is taken as -0.14 MPa in this example.

[0048] The variables in the above formula are specifically as follows in the embodiment: ; ; ; Calculated Feedback control correction amount at any time for: .

[0049] Feedback control correction amount Feedback regulation current needs to be converted to the corresponding physical dimensions To achieve dimensional uniformity with the feedforward signal, its conversion formula is as follows: ; in, The conversion coefficient from control quantity to drive current is set to 0.2mA in this embodiment, which is used to convert the dimensionless or normalized control quantity output by the PID algorithm into a current signal that can be recognized by the proportional valve amplifier. To provide feedback for current regulation, the calculation result in this embodiment is: .

[0050] A control signal superposition strategy is adopted to represent the combined effect of the feedforward regulation current and the feedback regulation current; the feedforward reference drive current and the feedback regulation current are linearly synthesized to generate the final composite drive current. The superposition formula is: ; in, The composite drive current signal is ultimately output as a current command to a three-position four-way proportional valve amplifier. This signal simultaneously contains the prediction component of feedforward control and the correction component of feedback control. The calculation result in this embodiment is... .

[0051] When a composite driving current is applied to a proportional directional valve, the target composite displacement generated by driving the valve core satisfies the following linear mapping relationship, thus determining the relationship between the valve core displacement and the current: ; in, for The target composite displacement of the valve core of the proportional directional valve at any given time is composed of the feedforward reference displacement and the displacement correction caused by feedback regulation. The valve core displacement is calculated in the embodiment. Negative displacement indicates that the valve core will move in the direction that connects the second accumulator to the high-voltage side.

[0052] The above formula shows that the final valve core reference displacement is based on the reference opening established by feedforward, and is superimposed with the fine-tuning displacement generated by feedback control, so as to achieve precise control of fluid flow.

[0053] Step S5: The controller of the pump-controlled hydraulic system maps the main valve core reference displacement command to the operating direction and port status of the proportional directional valve based on the high-pressure side oil circuit identified in step S1. The pump-controlled hydraulic system generates a composite drive current signal according to step S4, and controls the valve core movement to establish the corresponding oil circuit connection based on the sign and amplitude of the main command. By continuously controlling the valve core reference displacement, it actively adjusts the oil flow rate into or out of the second accumulator, dynamically changing the gas volume within the second accumulator, thereby maintaining the pump-controlled hydraulic system pressure within the target pressure setting range, suppressing pressure pulsation, and ultimately achieving the effect of actively suppressing the vibration of the pump-controlled hydraulic system. Specifically, this includes the following steps: Based on the flow rate setting, the oil flowing into the second accumulator instantly changes its oil volume, and the specific relationship between the compensation flow rate and the change in the volume inside the accumulator is as follows: ; in, for The volume of oil at any given time; for Total compensation flow at any given moment; for The volume derivative of the oil at time t.

[0054] Given that the total volume of the second accumulator is constant, the above formula shows that the gas volume inside the second accumulator will increase at a rate of 0.495 L / min, while the total gas-oil volume remains constant. Therefore, the gas volume and oil volume are complementary, and their specific relationship is as follows: ; in, This is the total volume of the second accumulator; for The gas volume in the second accumulator at that moment; for The volume of oil in the second accumulator at any given time.

[0055] Differentiating the above equation with respect to time, we obtain the relationship between the rate of change of gas volume and the compensated flow rate as follows: ; The above equation shows that the rate of change of gas volume is directly and uniquely determined by the compensation flow rate; that is, controlling the compensation flow rate is equivalent to directly controlling the rate of change of gas volume in the second accumulator. Under isothermal conditions, the gas in the second accumulator follows thermodynamic processes, indicating that an increase in gas volume will lead to a decrease in pressure, and the high-pressure side absorbs pressure pulsations, achieving vibration suppression control; specifically, as shown in the following equation: ; in, for The instantaneous pressure of the gas inside the second accumulator at a given moment; for The instantaneous volume of gas in the second accumulator at a given moment; This is the initial instantaneous pressure of the gas inside the second accumulator; This represents the initial instantaneous volume of the gas inside the second accumulator. is the gas state constant.

[0056] This demonstrates the physical basis of the pressure effect generated by volume control. When the gas volume changes, the pressure in the second accumulator also changes, and this pressure is further transmitted to the pump-controlled hydraulic system to actively counteract the pressure pulsation.

[0057] Total compensation flow The main pipeline of the pump-controlled hydraulic system is injected into or drawn out; based on the principle of fluid continuity and the gaseous state equation of the second accumulator, this flow rate will... Pressure of the main oil circuit at the load end at any given time This process is qualitatively described by the following equation: ; in, for Total compensation flow at any given moment; for The pump source output flow rate at any given time; for Traffic consumption at any given moment; This refers to the total effective volume of the pump-controlled hydraulic system. This refers to the effective bulk elastic modulus of the oil. This represents the leakage coefficient of the pump-controlled hydraulic system.

[0058] The formula Substituting into the above formula, we get: ; in, for The pump source output flow rate at any given time; for Traffic consumption at any given moment.

[0059] The above formula intuitively reveals the active change rate of the gas volume of the second accumulator, which is used to offset the disturbances of the pump source and load, directly suppressing the pressure changes of the pump-controlled hydraulic system, and ultimately achieving the vibration suppression effect of the pump-controlled hydraulic system.

[0060] like Figure 5The figure shows a comparison of the pressure pulsation suppression effects of passive control and composite control in an embodiment of the present invention. In the figure, the ordinary accumulator represents passive control, and the accumulator and the three-position four-way directional valve connected in series represent composite control. The figure shows that the second accumulator and the three-position four-way directional valve connected in series have a better effect on absorbing pressure pulsations than the ordinary accumulator structure.

[0061] A second aspect of this invention provides a pump-controlled hydraulic system based on an active volumetric regulation-based pump-controlled hydraulic vibration control method, such as... Figure 3 As shown, it includes: a servo motor 1, a coupling 2, a bidirectional quantitative hydraulic pump 3, a first check valve 4, a second check valve 5, a first relief valve 6, a second relief valve 7, a filter 8, a replenishing pressure relay 9, a temperature sensor 10, a proportional directional valve 11, a first flow meter 12, a second flow meter 13, a first pressure sensor 14, a second pressure sensor 15, a hydraulic cylinder 16, a left-side load 17, a right-side load 18, a first accumulator 19, a second accumulator 20, a controller 21, and a high-pressure cooler 22.

[0062] The coordinated structure of the proportional directional valve 11 and the second accumulator 20 performs active volume control. The continuous displacement adjustment of the proportional directional valve 11 serves as the carrier to dynamically adjust the flow rate of oil flowing into or out of the second accumulator 20, thereby changing the gas volume inside the second accumulator 20.

[0063] Servo motor 1 is connected to bidirectional quantitative hydraulic pump 3 via coupling 2, serving as the power source for the pump-controlled hydraulic system. The inlets of the first check valve 4 and the second check valve 5 are connected to the first accumulator 19, and their outlets are also connected to the first accumulator 19. The inlet of filter 8 is connected to the bidirectional quantitative hydraulic pump 3, and its outlet is connected to the first accumulator 19. The replenishing pressure relay 9 and the temperature sensor 10 are connected to the first accumulator 19. The inlet of the first relief valve 6 is connected to the left-side pipeline, and the inlet of the second relief valve 7 is connected to the right-side pipeline. Both of their outlets are connected to the replenishing and overflow pipeline.

[0064] When abnormal high pressure occurs during normal operation of the pump-controlled hydraulic system, the relief valve opens to the working position, allowing excess oil to overflow back to the accumulator and stabilizing the pressure within the predetermined range.

[0065] A high-pressure cooler 22 is connected in series in the pipeline to continuously cool the oil in the pump-controlled hydraulic system and control the temperature of the pump-controlled hydraulic system. The first flow meter 12, the second flow meter 13, the first pressure relay 14, and the second pressure relay 15 are connected to the left and right pipelines, respectively. The first flow meter 12 and the second flow meter 13 are connected in series in the pipeline. The first pressure relay 14 and the second pressure relay 15 detect the pressure of the pump-controlled hydraulic system in real time, enabling the pump-controlled hydraulic system to operate and transmitting the pressure data to the controller 21. The second accumulator 20 is connected to the left and second oil circuits of the pump-controlled hydraulic system through the proportional directional valve 11, respectively, to adapt to various working conditions. The first oil inlet of the hydraulic cylinder 16 is connected to the left pipeline, and the second oil inlet of the hydraulic cylinder 16 is connected to the right pipeline.

[0066] The beneficial effects of this invention are as follows: This invention proposes a pump-controlled hydraulic system for vibration control based on active volumetric regulation. By constructing a feedforward control based on a pump source flow pulsation model and a feedback control based on pressure deviation, a feedforward-feedback composite control strategy is achieved, realizing the synergistic effect of prediction and correction. By accurately identifying the high-pressure side, real-time adaptability of bidirectional pressure control is achieved, enhancing the working condition adaptability and control continuity of the hydraulic system. Active volumetric control is executed through the collaborative structure of the proportional directional valve and the second accumulator, overcoming the limitations of traditional hydraulic systems where pressure fluctuation suppression relies on passive buffering or fixed parameter adjustment, improving the accuracy and response speed of pressure control, and thus enhancing the pressure stability and anti-interference performance of the hydraulic system under complex working conditions.

[0067] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A pump-controlled hydraulic vibration control method based on active volume regulation, characterized in that, It includes: S1: The controller of the pump-controlled hydraulic system collects the pressure data measured by the first pressure sensor in real time. Pressure data measured by the second pressure sensor The current high-pressure side oil circuit is identified by comparing the pressure difference. S2: Acquire the rotation angle and speed signals from the encoder of the servo motor of the bidirectional fixed displacement hydraulic pump; determine the instantaneous theoretical flow rate output by the pump source based on the flow pulsation model of the bidirectional fixed displacement hydraulic pump. ; The target compensation flow rate is injected into the main oil circuit by adjusting the proportional directional valve. Used to offset theoretical pressure fluctuations; to solve for the feedforward valve core reference displacement required by the proportional directional valve. Based on the current high-pressure side oil circuit identified in step S1, directional adaptation is performed so that the direction of feedforward control always corresponds to the pressure side to be maintained, thereby actively suppressing pump source pulsation. S3: Use the controller of the pump-controlled hydraulic system to obtain the actual pressure signal of the current high-pressure side oil circuit identified in step S1, and compare it with the preset target pressure signal in real time to determine the real-time pressure deviation value. Monitor real-time pressure deviation values The absolute value, and compared with the preset pressure fluctuation threshold. The comparison is made to determine whether to activate the feedback control loop; S4: Obtain the judgment result of step S3. When the feedback control loop is triggered, the real-time pressure deviation value will be... As input variables, the feedback control correction is determined using a PID algorithm. Simultaneously, the reference displacement of the feedforward valve core determined in step S2 is obtained. Based on the displacement-gain characteristics of the proportional directional valve, the reference displacement of the feedforward valve core is... As the corresponding feedforward reference drive current A control signal superposition strategy is adopted to superimpose the feedforward reference drive current. With feedback regulation current Linear superposition is performed to generate a composite drive current signal. The target composite displacement of the valve core of the proportional directional valve is obtained. To regulate fluid flow; S5: Based on the current high-pressure side oil circuit identified in step S1, map the main valve core reference displacement command to the operating direction and port status of the proportional directional valve; based on the valve core target composite displacement obtained in step S4... This maintains the pressure of the pump-controlled hydraulic system within the target pressure setting range.

2. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 1, characterized in that: Step S1, which identifies the current high-pressure side oil circuit, specifically includes: when When the first pressure sensor is located, it is determined that the oil circuit is on the high-pressure side and the condition is set to positive. when When the second pressure sensor is located, it is determined that the oil circuit is on the high-pressure side, and the reverse operating condition is set. The high-pressure side oil circuit identification logic runs continuously, providing real-time directional information for the bidirectional pressure control of the pump-controlled hydraulic system.

3. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 1, characterized in that: Step S2 is as follows: S21: Based on the instantaneous theoretical flow rate of the bidirectional fixed displacement hydraulic pump source. Relationship with rotation angle and angular velocity; hydraulic pump discharge period function Expanding to Fourier series form, and substituting the instantaneous theoretical flow rate of the hydraulic pump source... In the process, the flow pulsation model of the bidirectional fixed displacement hydraulic pump is obtained, and the flow rate of the bidirectional fixed displacement hydraulic pump is output. ; S22: In the complex frequency domain, through the hydraulic impedance of the pump-controlled hydraulic system Describing the theoretical pressure fluctuation components With the flow pulsation of the bidirectional fixed displacement hydraulic pump source Relationship; inject the target compensation flow into the main oil circuit by adjusting the proportional directional valve. To offset theoretical pressure fluctuations; S23: Determine the feedforward valve spool reference displacement required for the proportional directional valve. Based on the displacement-gain mapping formula of the proportional directional valve, the conversion relationship between valve core displacement and drive current, and the relationship between drive current and compensation flow are determined; the feedforward flow demand corresponding to the theoretical pressure fluctuation component is converted into the feedforward reference drive current.

4. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 3, characterized in that: The bidirectional fixed displacement hydraulic pump flow rate output in step S21 for: ； in, This refers to the flow rate of a bidirectional fixed displacement hydraulic pump. This refers to the shaft rotation angle of a bidirectional quantitative hydraulic pump. This refers to the angular velocity of the shaft of a bidirectional quantitative hydraulic pump. The zeroth harmonic coefficient; This refers to the average flow rate output by the bidirectional fixed displacement hydraulic pump. For the first The amplitude coefficient of the first harmonic; m is the harmonic order; For the first The initial phase of the first harmonic; The spatial frequency of the pulsating fundamental frequency; It is a sine function; The symbol for infinity; This refers to the flow pulsation component output by the bidirectional fixed displacement hydraulic pump.

5. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 3, characterized in that: In step S22, the target compensation flow rate is injected into the main oil circuit by adjusting the proportional directional valve. To offset theoretical pressure fluctuations, specifically: ； in, for The flow rate through the proportional directional valve at any given time; For flow coefficient; The valve orifice area gradient; for The reference displacement of the feedforward valve core at any given moment; The density of the oil; for The pressure of the main oil circuit at the load end at any given time; for The pressure inside the accumulator at any given moment; For flow direction sign function; This is a time parameter.

6. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 3, characterized in that: The feedforward reference drive current obtained in step S23 is: ； in, for The feedforward reference drive current of the proportional directional valve at any given time; for The target compensation flow rate of the main oil circuit at any given time; This is the displacement-current gain coefficient of the proportional directional valve.

7. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 1, characterized in that: In step S3, monitor the real-time pressure deviation value. The absolute value, and compared with the preset pressure fluctuation threshold. A comparison is made to determine whether to activate the feedback control loop, specifically: Determine the real-time pressure deviation value Is the absolute value greater than the preset pressure fluctuation threshold? If the real-time pressure deviation value The absolute value is less than or equal to the preset pressure fluctuation threshold. If the current pressure fluctuation only needs to trigger the feedforward control loop to maintain the current feedforward control output, then the current pressure fluctuation should be considered as a separate event. The absolute value is greater than the preset pressure fluctuation threshold. If a disturbance or model error is detected that is not covered by the model prediction, a feedback control loop is triggered to stabilize the pressure at the target value.

8. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 1, characterized in that: In step S4, the target composite displacement of the valve core of the proportional directional valve is obtained. Specifically ； ； ； in, for The target composite displacement of the valve core of the proportional directional valve at any given time; It is a composite drive current signal; for The reference displacement of the feedforward valve core of the proportional directional valve at any given moment; For feedback regulation of current; The conversion coefficient from control quantity to drive current; for The amount of feedback control correction at any given time.

9. The pump-controlled hydraulic vibration control method based on active volume regulation according to claim 1, characterized in that: In step S5, the pressure of the pump-controlled hydraulic system is maintained within the target pressure setting range. Specifically, this is achieved by using the active change rate of gas volume of the second accumulator to counteract disturbances in the pump source and load. ； in, for Total compensation flow at any given moment; for The pump source output flow rate at any given time; for Traffic consumption at any given moment; This refers to the total effective volume of the pump-controlled hydraulic system. This refers to the effective bulk elastic modulus of the oil. This represents the leakage coefficient of the pump-controlled hydraulic system.

10. A pump-controlled hydraulic system for the pump-controlled hydraulic vibration control method based on active volume regulation as described in any one of claims 1 to 9, comprising: The system comprises a servo motor, coupling, bidirectional quantitative hydraulic pump, first check valve, first relief valve, second relief valve, filter, replenishment pressure relay, temperature sensor, first flow meter, second flow meter, first pressure sensor, second pressure sensor, hydraulic cylinder, left-side load, right-side load, first accumulator, controller, and high-pressure cooler; characterized in that it includes a proportional directional valve and a second accumulator. The coordinated structure of the proportional directional valve and the second accumulator performs active volume control. Using the continuous displacement adjustment of the proportional directional valve as the carrier, it dynamically adjusts the flow rate of oil flowing into or out of the second accumulator, thereby changing the gas volume in the second accumulator and performing pump-controlled hydraulic vibration control. The second accumulator is connected to the first oil circuit and the second oil circuit of the pump-controlled hydraulic system through the proportional directional valve, respectively.

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