Pressure release valve on-off control system and method

Abstract

The invention provides a pressure release valve switch control system and method, and relates to the technical field of oil injection control, and the system comprises a pressure obtaining unit which is used for obtaining the real-time pressure of a pressure release valve; the condition generation unit is used for generating a pressure relief triggering condition according to the real-time pressure, the valve opening threshold pressure and the delay time corresponding to the opening and closing process of the pressure relief valve; the trigger detection unit is used for generating a pressure relief control signal according to the pressure relief trigger condition; the oil injection prediction unit is used for predicting the oil injection duration corresponding to the current oil injection period according to the initial flow characteristic coefficient and the corresponding historical opening and closing pressure of the pressure release valve in the historical oil injection period; and the oil injection control unit is used for controlling oil injection of the pressure release valve at regular time according to the pressure release control signal and the oil injection duration and then closing the valve. According to the system and method provided by the invention, the correspondence between the valve pressure of the switching valve and the threshold pressure of the switching valve can be ensured, and the accuracy of switching valve control based on the threshold pressure of the switching valve is improved.

Description

Technical Field

[0001] This invention relates to the field of fuel injection control technology, and in particular to a pressure relief valve switching control system and method. Background Technology

[0002] Fuel injection control is a core technology of the engine management system. It receives real-time data such as crankshaft position and oxygen sensor readings through the electronic control unit (ECU), dynamically calculates the fuel injection quantity, and controls the injectors to execute injection. Its core task is to determine the basic injection pulse width based on intake parameters and engine operating conditions, and optimize the air-fuel ratio by combining strategies such as voltage correction and dynamic compensation, covering multi-mode regulation in stages such as start-up, warm-up, and power enrichment.

[0003] In the process of opening and closing, existing pressure relief valves require further action after receiving the opening or closing command. The time delay of the opening or closing action makes it impossible for the valve pressure at the time of opening or closing to correspond to the opening and closing pressure required for precise control. As a result, pressure relief valves are difficult to apply in high-precision fuel injection control fields such as high-pressure common rail fuel injection systems. Summary of the Invention

[0004] This invention provides a pressure relief valve switching control system and method to solve the technical problem that, after receiving a valve opening or closing command, the valve still needs to perform further valve opening or closing actions, and the time delay of the valve opening or closing actions causes the valve pressure when opening or closing to not correspond to the opening and closing pressure required for precise control.

[0005] To achieve the above and other related objectives, the present invention provides a pressure relief valve switching control system, comprising: a pressure acquisition unit for acquiring the real-time pressure of the pressure relief valve; a condition generation unit for generating pressure relief trigger conditions based on the real-time pressure, the valve opening threshold pressure, and the delay time corresponding to the pressure relief valve switching process; a trigger detection unit for performing pressure relief trigger detection on the real-time pressure according to the pressure relief trigger conditions, and generating a pressure relief control signal when the real-time pressure meets the pressure relief trigger conditions; an injection prediction unit for predicting the injection duration corresponding to the current injection cycle based on the initial flow characteristic coefficient and the historical opening and closing pressures of the pressure relief valve in historical injection cycles, wherein the initial flow characteristic coefficient is calibrated by the oil medium under the same operating conditions at different test opening pressures and different test closing pressures corresponding to different test injection durations; and an injection control unit for controlling the pressure relief valve to inject oil at timed intervals and then closing the valve according to the pressure relief control signal and the injection duration.

[0006] In one embodiment of the present invention, the condition generation unit includes: a pressure rise analysis subunit, used to perform pressure rise trend analysis based on real-time pressure to obtain pressure rise trend data corresponding to each moment when the real-time pressure is in the rising phase, the pressure rise trend data including pressure rise rate and pressure rise acceleration; a pressure rise time prediction subunit, used to predict the predicted pressure rise time corresponding to the pressure rise from the corresponding real-time pressure to the valve opening threshold pressure based on the pressure rise trend data; a pressure rise amount prediction subunit, used to predict the cumulative pressure rise corresponding to each moment within the delay time based on the time difference and the pressure rise trend data when the time difference between the predicted pressure rise time and the delay time corresponding to the opening of the pressure relief valve reaches the trigger time threshold; and a pressure rise judgment subunit, used to judge whether the cumulative pressure rise corresponding to each moment is within the range of the cumulative pressure drop threshold corresponding to the preset trend data at each moment of valve opening, wherein the preset trend data includes the pressure relief rate and pressure relief acceleration corresponding to different valve opening degrees at each moment during the opening of the pressure relief valve; if yes, then a pressure relief trigger condition is generated based on the real-time pressure and the delay time; if no, then the valve is directly opened to relieve pressure and a warning message is generated.

[0007] In one embodiment of the present invention, the trigger detection unit includes: a time judgment subunit, used to determine whether the predicted pressure rise time is the same as the delay time when the time difference between the predicted pressure rise time corresponding to the real-time pressure rising to the valve opening threshold pressure and the delay time corresponding to the opening of the pressure relief valve is within the trigger time threshold range; and a signal generation subunit, used to record the real-time pressure at the corresponding moment and generate a pressure relief control signal when the predicted pressure rise time is the same as the delay time.

[0008] In one embodiment of the present invention, the fuel injection prediction unit includes: a coefficient correction subunit, used to continuously correct the initial flow characteristic coefficient according to the historical opening pressure when the pressure relief valve is actually opened, the historical closing pressure after the pressure relief valve is actually closed, and the valve closing threshold pressure corresponding to each historical fuel injection cycle, in the order of the historical fuel injection cycles, to obtain the target flow characteristic coefficient corresponding to the current fuel injection cycle; a data reading subunit, used to read the target flow characteristic coefficient according to the pressure relief control signal, and use the real-time pressure corresponding to the generation of the pressure relief control signal as the opening pressure of the current fuel injection cycle; and a duration calculation subunit, used to predict the fuel injection duration corresponding to the current fuel injection cycle according to the target flow characteristic coefficient, the opening pressure, the valve closing threshold pressure, and the delay time; the formula for calculating the fuel injection duration is: ;in, This indicates the injection duration corresponding to the current injection cycle. Represents the target flow characteristic coefficient. This indicates the opening pressure corresponding to the current injection cycle. Indicates the valve closing threshold pressure. Indicates the delay time. This indicates the current fuel injection cycle.

[0009] In one embodiment of the present invention, the coefficient correction subunit includes: an error calculation module, used to obtain the historical pressure error based on the historical shut-off pressure and valve-closing threshold pressure corresponding to each historical injection cycle; and a coefficient calculation module, used to obtain the target flow characteristic coefficient corresponding to the current injection cycle based on the historical pressure error, the target dynamic adjustment factor, and the initial flow characteristic coefficient.

[0010] In one embodiment of the present invention, the formula for calculating historical pressure error is: ;in, Indicates historical pressure error. Indicates the first The historical shut-off pressure corresponding to each historical injection cycle This represents the valve-closing threshold pressure; the formula for calculating the target flow characteristic coefficient is: ;in, Represents the target flow characteristic coefficient. Represents the initial flow characteristic coefficient. This represents the target dynamic adjustment factor.

[0011] In one embodiment of the present invention, the coefficient calculation module includes: a characteristic inverse calculation submodule, used to obtain the actual value of the previous flow characteristic coefficient based on the previous historical closing pressure, the previous historical opening pressure and the previous historical injection duration corresponding to the previous injection cycle; and a dynamic verification submodule, used to predict the target dynamic adjustment factor corresponding to the current injection cycle based on the previous flow characteristic coefficient, the actual value of the previous flow characteristic coefficient, the previous historical closing pressure and the valve closing threshold pressure corresponding to the previous injection cycle, so as to obtain the target flow characteristic coefficient corresponding to the current injection cycle based on the historical pressure error, the target dynamic adjustment factor and the initial flow characteristic coefficient.

[0012] In one embodiment of the present invention, the formula for calculating the target dynamic adjustment factor is: ;in, Indicates the target dynamic adjustment factor. This represents the actual value of the previous flow characteristic coefficient. This represents the previous flow characteristic coefficient. Indicates the duration of the previous historical fuel injection. This indicates the pressure that began in the previous historical period. This indicates the pressure of closing down in the previous history. Indicates the valve closing threshold pressure. This indicates the previous historical pressure error.

[0013] In one embodiment of the present invention, the fuel injection control unit includes: a timing subunit, used to control the opening of the pressure relief valve according to the pressure relief control signal, and send the fuel injection duration to a timer to control the timing of the timer through the fuel injection duration; and a shutdown control subunit, used to generate a shutdown control signal when the timer ends to control the valve shutdown of the pressure relief valve.

[0014] To achieve the above and other related objectives, the present invention also provides a pressure relief valve switching control method, comprising: acquiring the real-time pressure of the pressure relief valve through a pressure acquisition unit; generating a pressure relief trigger condition through a condition generation unit based on the real-time pressure, the valve opening threshold pressure, and the delay time corresponding to the pressure relief valve switching process; performing pressure relief trigger detection on the real-time pressure according to the pressure relief trigger condition through a trigger detection unit, and generating a pressure relief control signal when the real-time pressure meets the pressure relief trigger condition; predicting the injection duration corresponding to the current injection cycle through an injection prediction unit based on the initial flow characteristic coefficient and the historical opening and closing pressures corresponding to the pressure relief valve in historical injection cycles, wherein the initial flow characteristic coefficient is calibrated by the oil medium under the same working conditions at different test opening pressures and different test closing pressures corresponding to different test injection durations; and controlling the pressure relief valve to inject oil at timed intervals and then close the valve through an injection control unit based on the pressure relief control signal and the injection duration.

[0015] The beneficial effects of this invention are as follows: The pressure relief valve switching control system and method proposed in this invention can generate pressure relief trigger conditions corresponding to real-time pressure changes based on the real-time pressure of the pressure relief valve, the valve opening threshold pressure, and the delay time corresponding to the valve opening and closing process. This allows for the generation of a pressure relief control signal before the valve opening threshold pressure is reached when the real-time pressure meets the pressure relief trigger conditions, thus enabling early valve opening control of the pressure relief valve. This improves the correspondence between the pressure when the valve is officially opened and the valve opening threshold pressure, enhancing the accuracy of valve opening control based on the valve opening threshold pressure. Furthermore, before valve opening control, the initial flow characteristic coefficient and the historical opening and closing pressures of the pressure relief valve at the beginning and end of each historical injection cycle are used to dynamically adjust the overall characteristic quantification value of the overall characteristics that dynamically change with the continuous use of the oil medium, such as damping, which characterizes the pressure relief time of the oil medium within the current pressure relief valve. This is the initial flow characteristic coefficient, which allows for accurate prediction of the injection duration of the current injection cycle using the dynamically adjusted flow characteristic coefficient. In addition, after obtaining the injection time, the pressure relief valve can be opened using the pressure relief control signal to inject fuel. Furthermore, by using the injection duration to time the injection, the valve can be directly closed when the injection time ends. This ensures the correspondence between the valve pressure after valve closure and the valve closure threshold pressure, improving the accuracy of valve closure control based on the valve closure threshold pressure. This allows for better application in high-precision fuel injection control fields such as high-pressure common rail fuel injection systems. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram: Figure 1 This is a structural block diagram of the pressure relief valve switching control system provided in an embodiment of the present invention; Figure 2 The diagram shown illustrates the structural block diagram of the pressure relief valve switching control process according to an embodiment of the present invention. Figure 3 The diagram shown is a flowchart illustrating a pressure relief valve switching control method provided in an embodiment of the present invention.

[0018] The attached figures are labeled as follows: Pressure acquisition unit 10; condition generation unit 20; trigger detection unit 30; fuel injection prediction unit 40; fuel injection control unit 50. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0022] Please see Figure 1This invention provides a pressure relief valve switching control system, comprising: a pressure acquisition unit 10 for acquiring the real-time pressure of the pressure relief valve; a condition generation unit 20 for generating pressure relief trigger conditions based on the real-time pressure, the valve opening threshold pressure, and the delay time corresponding to the pressure relief valve switching process; a trigger detection unit 30 for performing pressure relief trigger detection on the real-time pressure according to the pressure relief trigger conditions, and generating a pressure relief control signal when the real-time pressure meets the pressure relief trigger conditions; an injection prediction unit 40 for predicting the injection duration corresponding to the current injection cycle based on the initial flow characteristic coefficient and the historical opening and closing pressures of the pressure relief valve in the historical injection cycle, wherein the initial flow characteristic coefficient is calibrated by the oil medium under the same working condition at different test opening pressures and different test closing pressures corresponding to different test injection durations; and an injection control unit 50 for controlling the pressure relief valve to inject oil at timed intervals and then closing the valve according to the pressure relief control signal and the injection duration.

[0023] As can be seen from the above, in the process of controlling the pressure relief valve by injecting oil based on the valve opening threshold pressure and the valve closing threshold pressure, in order to ensure the accuracy of the valve opening and closing actions, the pressure acquisition unit can first acquire the real-time pressure of the pressure relief valve. Then, the condition generation unit 20 can generate a pressure relief trigger condition corresponding to the real-time pressure change based on the real-time pressure, the valve opening threshold pressure, and the delay time corresponding to the valve opening and closing process. Thus, when the trigger detection unit 30 detects that the real-time pressure meets the pressure relief trigger condition, a pressure relief control signal can be generated in advance before the valve opening threshold pressure is reached, and the pressure relief valve can be opened in advance. This ensures the correspondence between the pressure when the valve is officially opened and the valve opening threshold pressure, thereby improving the accuracy of valve opening control based on the valve opening threshold pressure. Furthermore, before valve opening control, the injection prediction unit 40 utilizes the initial flow characteristic coefficient and the historical opening and closing pressures of the pressure relief valve at the beginning and end of each historical injection cycle to dynamically adjust the overall characteristic quantification value of the overall characteristics that dynamically change with the continuous use of the oil medium, such as damping, which characterizes the pressure relief time of the oil medium within the current pressure relief valve. This is the initial flow characteristic coefficient, thereby enabling accurate prediction of the injection duration of the current injection cycle using the dynamically adjusted flow characteristic coefficient. Additionally, after obtaining the injection time, the injection control unit 50 can open the pressure relief valve based on the pressure relief control signal to perform injection. By using the injection duration for injection timing, the valve is directly closed at the end of the injection timing, ensuring the correspondence between the valve pressure after valve closure and the valve closure threshold pressure. This improves the accuracy of valve closure control based on the valve closure threshold pressure, thus enabling better application in high-precision injection control fields such as high-pressure common rail injection systems.

[0024] In acquiring real-time pressure, a pressure sensor can be installed on each pressure relief valve. When the pressure sensor receives an oil pressure signal, it converts the signal into a digital signal and sends it to the pressure acquisition unit 10. Alternatively, the pressure acquisition unit 10 can actively acquire the pressure. Furthermore, to ensure the accuracy of the actual pressure determination, after continuously sampling the oil pressure data corresponding to the pressure sensor, the data can be further filtered to determine the real-time pressure that truly reflects the oil pressure changes. The filtering process can include at least one of three-point median filtering and IIR filtering.

[0025] In determining the relationship between the injection duration, opening pressure, and closing pressure of the pressure relief valve, Bernoulli's equation can be used. Specifically, for a thin-walled orifice, the volumetric flow rate per unit time can be expressed by the formula: Simplified to: Considering bulk modulus Therefore, in a single fuel injection process, Since it is a constant, we can integrate it over time to obtain the relationship between the rate of change of pressure and the rate of change of volume (i.e., flow rate): That is The formula With formula Combining these equations, we obtain the differential equation: The integral relationship can be expressed as: Thus, the relationship between injection duration, opening pressure, and closing pressure is determined as follows: .in, This indicates the back pressure of the pressure relief valve. Indicates volumetric flow rate, Indicates the flow coefficient. Indicates the valve opening area. Indicates the density of the oil. This indicates the elastic modulus of the oil. Indicates the volume of oil. This indicates the total volume of oil inside the pressure relief valve. Indicates time, Indicates the duration of fuel injection. Indicates pressure closure. Indicates that pressure is activated. Represents the flow characteristic coefficient. , and These are the simplified coefficients for each parameter in the corresponding formula.

[0026] The relationship between injection duration, opening pressure, and closing pressure is as follows: The calculation formula shows that, once the opening and closing pressures are determined, the injection duration is affected by the flow characteristic coefficient. The influence of different injection cycles on the flow characteristic coefficient during oil use. This will also be affected accordingly. Therefore, the flow characteristic coefficient corresponding to the injection cycle can be continuously and dynamically adjusted based on the initial flow characteristic coefficient. This effectively ensures the accuracy of the predicted injection duration. Based on this injection duration and the corresponding pressure relief control signal, the pressure relief valve can be opened and closed at regular intervals to ensure reliable valve opening when the opening pressure reaches the valve opening threshold pressure and reliable valve closing when the closing pressure reaches the valve closing threshold pressure.

[0027] It is worth noting that the initial flow characteristic coefficient can be determined by averaging the test values ​​of the flow characteristic coefficient obtained under the same operating conditions through different test injection durations of the oil medium at the test opening pressure and test closing pressure.

[0028] Specifically, the formula for calculating the initial flow characteristic coefficient can be expressed as: ; in, Represents the initial flow characteristic coefficient. Indicates the number of trials, Indicates the first The test start pressure corresponding to this test. Indicates the first The test shut-off pressure corresponding to this test. Indicates the first The test injection duration corresponding to this test.

[0029] In the pressure relief valve switching control system of the present invention, the condition generation unit 20 may further include: a pressure rise analysis subunit, used to perform pressure rise trend analysis based on real-time pressure to obtain pressure rise trend data corresponding to each moment when the real-time pressure is in the rising phase, the pressure rise trend data including pressure rise rate and pressure rise acceleration; a pressure rise time prediction subunit, used to predict the predicted pressure rise time corresponding to the pressure rise from the corresponding real-time pressure to the valve opening threshold pressure based on the pressure rise trend data; a pressure rise amount prediction subunit, used to predict the cumulative pressure rise corresponding to each moment within the delay time based on the time difference and pressure rise trend data when the time difference between the predicted pressure rise time and the delay time corresponding to the opening of the pressure relief valve reaches the trigger time threshold; and a pressure rise judgment subunit, used to judge whether the cumulative pressure rise corresponding to each moment is within the range of the cumulative pressure drop threshold corresponding to the preset trend data at each moment of valve opening, wherein the preset trend data includes the pressure relief rate and pressure relief acceleration corresponding to different valve opening degrees at each moment during the opening of the pressure relief valve; if yes, then a pressure relief trigger condition is generated based on the real-time pressure and the delay time; if no, then the valve is directly opened for pressure relief and a warning message is generated. The preset trend data includes preset pressure relief acceleration at different times within the delay period.

[0030] During the generation of pressure relief trigger conditions, the pressure rise trend at the current stage can be analyzed by the pressure rise analysis subunit, which collects real-time pressure data at different times. This allows for the identification of the pressure rise rate and acceleration at each moment during the oil pressure rise phase. After obtaining the pressure rise rate and acceleration, the pressure rise time prediction subunit can further predict the predicted pressure rise time required to continue increasing the pressure at the same rate and acceleration, and when the real-time pressure reaches the valve opening threshold pressure. This predicted pressure rise time can then be used to reflect whether there are any abnormalities in the current oil pressure, allowing for the generation of pressure relief trigger conditions for pressure relief control under normal conditions. In abnormal situations, to ensure the safe operation of the pressure relief valve, the oil pressure can be immediately released to protect the valve, and corresponding abnormal data can be reported.

[0031] Specifically, after the pressure rise time prediction subunit predicts the predicted pressure rise time, it compares the predicted pressure rise time with the delay time through the pressure rise amount prediction subunit. When the time difference between the predicted pressure rise time and the delay time corresponding to the opening of the pressure relief valve reaches the trigger time threshold range before the delay time, that is, when the time difference is less than the trigger time threshold, the pressure relief trigger condition judgment mechanism can be further activated based on the time difference and pressure rise trend data. First, based on the current real-time pressure, time difference, pressure rise rate, and pressure rise acceleration, the pressure rise rate and acceleration corresponding to the end of the time difference can be predicted. Then, based on the pressure rise rate and acceleration corresponding to the end of the time difference, the cumulative pressure rise amount corresponding to each moment within the delay time can be predicted. Finally, the pressure increase judgment subunit compares the cumulative pressure increase at each moment with the cumulative pressure decrease threshold corresponding to the preset trend data at each moment of valve opening. This determines whether the cumulative pressure increase at each moment is within the cumulative pressure decrease threshold range corresponding to the preset trend data at each moment of valve opening. If it is within the cumulative pressure decrease threshold range, the real-time pressure and delay time are used to continue monitoring within the time difference of the real-time pressure continuing to rise, to determine whether the real-time pressure will trigger the pressure relief trigger condition. If the cumulative pressure increase value is not within the cumulative pressure decrease threshold range, it indicates that the current pressure increase is abnormal, and the pressure relief valve needs to be released in time to prevent damage to the pressure relief valve and the occurrence of danger. This achieves timely control of the pressure relief valve threshold and ensures valve body safety.

[0032] Specifically, when comparing the cumulative boost value with the cumulative buck threshold based on each moment within the delay time, the following formula can be used to determine whether it holds true: ; in, This represents the real-time pressure forecast value corresponding to the end of the time difference (the start of the delay time). Indicates the delay time. This indicates the predicted boost rate corresponding to the end of the time difference (the start of the delay time). This represents the predicted boost acceleration at the end of the time difference (the start of the delay time), based on the change in boost acceleration before the start of the time difference. Indicates the valve opening threshold pressure. This indicates different times during the delay period of the pressure relief valve opening process. The corresponding preset pressure relief acceleration.

[0033] In the pressure relief valve switching control system of the present invention, the trigger detection unit 30 may further include: a time judgment subunit, used to determine whether the predicted pressure rise time is the same as the delay time when the time difference between the predicted pressure rise time corresponding to the real-time pressure rise to the valve opening threshold pressure and the delay time corresponding to the opening of the pressure relief valve is within the trigger time threshold range; and a signal generation subunit, used to record the real-time pressure at the corresponding moment and generate a pressure relief control signal when the predicted pressure rise time is the same as the delay time.

[0034] After the pressure relief trigger condition is generated, to ensure the pressure relief response rate, the detection frequency can be appropriately increased when the time difference between the predicted pressure rise time corresponding to the real-time pressure rising to the valve opening threshold pressure and the delay time corresponding to the opening of the pressure relief valve is within the trigger time threshold range. This means determining whether the predicted pressure rise time is the same as the delay time. When the predicted pressure rise time is the same as the delay time, the signal generation subunit records the real-time pressure at this time as the opening pressure corresponding to the current injection cycle and generates a corresponding pressure relief control signal to drive the pressure relief valve to perform the valve opening action. It is worth noting that the time from the sending of the drive signal to the complete opening of the pressure relief valve can be used as the delay time in this invention. Of course, this delay time can also represent the time taken from the issuance of the valve closing signal to the complete closure of the valve during the pressure relief valve closing process. Furthermore, in the specific opening and closing process, to reduce errors in the opening and closing process, the drive voltage can be reduced accordingly during the opening process and increased accordingly during the closing process based on the PWM pulse width modulation control principle to overcome oil pressure resistance, thereby ensuring that the delay time corresponding to the opening and closing processes is the same.

[0035] In the pressure relief valve switching control system of the present invention, the fuel injection prediction unit 40 includes: a coefficient correction subunit, used to continuously correct the initial flow characteristic coefficient according to the historical opening pressure when the pressure relief valve is actually opened, the historical closing pressure after the pressure relief valve is actually closed, and the valve closing threshold pressure corresponding to each historical fuel injection cycle, in the order of the historical fuel injection cycle, to obtain the target flow characteristic coefficient corresponding to the current fuel injection cycle; a data reading subunit, used to read the target flow characteristic coefficient according to the pressure relief control signal, and use the real-time pressure corresponding to the pressure relief control signal as the opening pressure of the current fuel injection cycle; and a duration calculation subunit, used to predict the fuel injection duration corresponding to the current fuel injection cycle according to the target flow characteristic coefficient, the opening pressure, the valve closing threshold pressure, and the delay time.

[0036] In the process of predicting fuel injection duration The formula for calculating the fuel injection duration is: ; in, This indicates the injection duration corresponding to the current injection cycle. Represents the target flow characteristic coefficient. This indicates the opening pressure corresponding to the current injection cycle. Indicates the valve closing threshold pressure. Indicates the delay time. This indicates the current fuel injection cycle.

[0037] In the fuel injection prediction unit 40, the coefficient correction subunit may further include: an error calculation module, used to obtain the historical pressure error based on the historical shut-off pressure and valve shut-off threshold pressure corresponding to each historical fuel injection cycle; and a coefficient calculation module, used to obtain the target flow characteristic coefficient corresponding to the current fuel injection cycle based on the historical pressure error, the target dynamic adjustment factor and the initial flow characteristic coefficient.

[0038] During the continuous correction of the initial flow characteristic coefficient, the error calculation module first determines the difference between the historical shut-off pressure and the valve threshold pressure in each historical injection cycle based on the historical shut-off pressure corresponding to each historical injection cycle, using this difference as the historical pressure error. Then, the coefficient calculation module calculates the historical pressure error for each historical injection cycle and, based on the target dynamic adjustment factor modulated for each historical injection cycle and the pre-set initial flow characteristic coefficient, calculates the target flow characteristic coefficient for the current injection cycle, ensuring the accuracy of the calculated target flow characteristic coefficient for the current injection cycle.

[0039] In calculating the historical pressure error, it can be obtained using the historical shut-off pressure and valve-closing threshold pressure corresponding to each historical injection cycle, and calculated using the historical pressure error calculation formula. Specifically, the historical pressure error calculation formula can be expressed as: ; in, Indicates historical pressure error. Indicates the first The historical shut-off pressure corresponding to each historical injection cycle Indicates the valve closing threshold pressure; In calculating the target flow characteristic coefficient, it can be obtained using the historical pressure error corresponding to each historical injection cycle, the target dynamic adjustment factor after the corresponding injection cycle modulation, and the initial flow characteristic coefficient, through the calculation formula for the target flow characteristic coefficient. Specifically, the calculation formula for the target flow characteristic coefficient can be expressed as: ; in, Represents the target flow characteristic coefficient. Represents the initial flow characteristic coefficient. This represents the target dynamic adjustment factor. By statistically analyzing the impact of each historical injection cycle on the initial flow characteristic coefficient, the target flow characteristic coefficient corresponding to the current injection cycle can be accurately calculated, thereby improving the accuracy of valve opening and closing control.

[0040] Specifically, in the coefficient correction subunit, the coefficient calculation module may further include: a characteristic back-calculation submodule, used to obtain the actual value of the previous flow characteristic coefficient based on the previous historical closing pressure, the previous historical opening pressure, and the previous historical injection duration corresponding to the previous injection cycle; and a dynamic verification submodule, used to predict the target dynamic adjustment factor corresponding to the current injection cycle based on the previous flow characteristic coefficient, the actual value of the previous flow characteristic coefficient, the previous historical closing pressure, and the valve closing threshold pressure corresponding to the previous injection cycle, so as to obtain the target flow characteristic coefficient corresponding to the current injection cycle based on the historical pressure error, the target dynamic adjustment factor, and the initial flow characteristic coefficient.

[0041] Preferably, the formula for calculating the target dynamic adjustment factor is: ; in, Indicates the target dynamic adjustment factor. This represents the actual value of the previous flow characteristic coefficient. This represents the previous flow characteristic coefficient. Indicates the duration of the previous historical fuel injection. This indicates the pressure that began in the previous historical period. This indicates the pressure of closing down in the previous history. Indicates the valve closing threshold pressure. This indicates the previous historical pressure error.

[0042] To achieve dynamic adjustment of the adjustment factor corresponding to the pressure error and ensure the accuracy of the target flow characteristic coefficient used to calculate the current injection cycle, the characteristic back-calculation submodule can be used after the previous injection cycle to utilize the previous historical shut-off pressure corresponding to the previous injection cycle. The pressure of the previous history and the previous historical fuel injection duration By using the formula for calculating the flow characteristic coefficient, the inverse calculation formula is derived: The actual value of the previous flow characteristic coefficient can be calculated by reverse calculation. Then, the dynamic verification submodule first checks the previous historical shutdown pressure. and valve threshold pressure Through calculation formula Calculate the previous historical pressure error Finally, the flow characteristic coefficient corresponding to the previous injection cycle is used. Actual value of the previous flow characteristic coefficient and the previous historical pressure error Through calculation formula To calculate the target flow characteristic coefficient corresponding to the current injection cycle. .

[0043] In the pressure relief valve switching control system of the present invention, the fuel injection control unit 50 may further include: a timing subunit, used to control the opening of the pressure relief valve according to the pressure relief control signal and send the fuel injection duration to the timer so as to control the timing of the timer through the fuel injection duration; and a closing control subunit, used to generate a closing control signal when the timer ends to control the valve closing of the pressure relief valve.

[0044] After predicting the injection duration for the current injection cycle, the timing subunit can pre-determine the injection duration based on the pressure relief control signal and send it to the timer. Simultaneously, it controls the pressure relief valve to open and release pressure, recording the real-time pressure at the time of valve opening as the opening pressure for the current injection cycle. Once the timer receives the injection duration, it automatically starts timing. When the timer reaches its end time, it receives the timer's end signal and generates a closing control signal for the pressure relief valve. After issuing the closing control signal, it waits for the corresponding delay time before closing the valve. After the valve is fully closed, the real-time pressure is again calculated as the closing pressure for the current injection cycle.

[0045] Please see Figure 2 The pressure relief valve switching control system of this invention can simultaneously control the opening and closing of multiple pressure relief valves. During the control process, the MCU can collect the real-time pressure from the pressure sensors on each pressure relief valve and monitor the real-time pressure at a threshold. When fuel injection control is required, the MCU sends the corresponding fuel injection duration to the timer for timing and controls all valves to open for fuel injection simultaneously. When the timer ends, it feeds back an end signal to the MCU, thereby enabling the MCU to control all valves to close, thus controlling the fuel injection action of the pressure relief valve.

[0046] It is worth noting that the historical valve opening pressure, historical valve closing pressure, and the valve opening pressure and valve closing pressure corresponding to the historical injection cycle in this invention are all actual pressures monitored by pressure sensors.

[0047] In addition, after calculating the valve closing pressure corresponding to the current injection cycle, the system will further calculate the next dynamic adjustment factor and the next flow characteristic coefficient corresponding to the next injection cycle based on the valve closing pressure, so as to calculate the next injection duration corresponding to the next injection cycle according to the next valve opening pressure corresponding to the next injection cycle.

[0048] Please see Figure 3 The present invention also provides a method for controlling the switching of a pressure relief valve, comprising: Step S10: Obtain the real-time pressure of the pressure relief valve through the pressure acquisition unit 10; Step S20: The condition generation unit 20 generates pressure relief trigger conditions based on the real-time pressure, valve opening threshold pressure, and the delay time corresponding to the pressure relief valve opening and closing process. Step S30: The trigger detection unit 30 performs pressure relief trigger detection on the real-time pressure according to the pressure relief trigger condition. When the real-time pressure meets the pressure relief trigger condition, a pressure relief control signal is generated. Step S40: The injection prediction unit 40 predicts the injection duration corresponding to the current injection cycle based on the initial flow characteristic coefficient and the historical opening and closing pressure of the pressure relief valve in the historical injection cycle. The initial flow characteristic coefficient is calibrated by the oil medium under the same working conditions at different test opening pressures and different test closing pressures corresponding to different test injection durations. Step S50: The fuel injection control unit 50 controls the timing of fuel injection into the pressure relief valve and then closes the valve based on the pressure relief control signal and the fuel injection duration.

[0049] In summary, the pressure relief valve switching control system and method disclosed in this invention can generate pressure relief trigger conditions corresponding to real-time pressure changes by using the acquired real-time pressure of the pressure relief valve, the valve opening threshold pressure, and the delay time corresponding to the valve opening and closing process. This allows for the generation of a pressure relief control signal before the valve opening threshold pressure is reached when the real-time pressure meets the trigger conditions, enabling early valve opening control of the pressure relief valve. This improves the accuracy of valve opening control based on the valve opening threshold pressure, ensuring a higher correlation between the valve's opening pressure and the threshold pressure. Furthermore, before valve opening control, the initial flow characteristic coefficient and the historical opening and closing pressures of the pressure relief valve at the beginning and end of each historical injection cycle are used to dynamically adjust the overall characteristic quantification value of the factors affecting the pressure relief time of the oil medium within the current pressure relief valve, such as damping, which dynamically change with the continuous use of the oil medium. This is the initial flow characteristic coefficient, which allows for accurate prediction of the injection duration of the current injection cycle using the dynamically adjusted flow characteristic coefficient. Furthermore, after obtaining the injection time, the pressure relief valve can be opened using a pressure relief control signal to initiate injection. By using the injection duration for timing, the valve can be directly closed at the end of the timing period. This ensures the correspondence between the valve pressure after closure and the valve closure threshold pressure, improving the accuracy of valve closure control based on the valve closure threshold pressure. This allows for better application in high-precision injection control fields such as high-pressure common rail injection systems. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial applicability.

[0050] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A pressure relief valve switch control system characterized by, The method comprises the following steps: a pressure acquisition unit is configured to acquire a real-time pressure of a pressure relief valve; a condition generation unit is configured to generate a pressure relief trigger condition according to the real-time pressure, an open valve threshold pressure, and a delay time corresponding to a pressure relief valve opening process; a trigger detection unit is configured to perform pressure relief trigger detection on the real-time pressure according to the pressure relief trigger condition, and generate a pressure relief control signal when the real-time pressure meets the pressure relief trigger condition; an oil injection prediction unit is configured to predict an oil injection duration corresponding to a current oil injection cycle according to an initial flow characteristic coefficient and historical open / close pressures of the pressure relief valve in historical oil injection cycles, wherein the initial flow characteristic coefficient is calibrated from different test opening pressures and different test closing pressures of the same working condition under different test injection durations of the oil medium; an oil injection control unit is configured to perform timed oil injection control on the pressure relief valve according to the pressure relief control signal and the oil injection duration, and then close the valve. The condition generation unit comprises:

2. The pressure relief valve switch control system of claim 1, wherein, a pressure rise analysis subunit configured to perform pressure rise trend analysis on the real-time pressure to obtain pressure rise trend data corresponding to each time point in an upward stage of the real-time pressure, wherein the pressure rise trend data comprises a pressure rise speed and a pressure rise acceleration; a pressure rise time prediction subunit configured to predict a predicted pressure rise time corresponding to a pressure rise from the corresponding real-time pressure to the open valve threshold pressure according to the pressure rise trend data; a pressure rise amount prediction subunit configured to predict a pressure rise cumulative amount corresponding to each time point in the delay time according to the time difference and the pressure rise trend data when a time difference between the predicted pressure rise time and the delay time corresponding to the opening of the pressure relief valve reaches a trigger time threshold; and a pressure rise judgment subunit configured to judge whether the pressure rise cumulative amount corresponding to each time point is within a pressure drop cumulative threshold range corresponding to preset trend data of valve opening time points, wherein the preset trend data comprises pressure relief speeds and pressure relief accelerations corresponding to different valve openings at each time point in the pressure relief valve opening process; if yes, the pressure relief trigger condition is generated according to the real-time pressure and the delay time; if no, the valve is directly opened for pressure relief, and a warning information is generated. The trigger detection unit comprises:

3. The pressure relief valve switch control system of claim 1, wherein a time judgment subunit configured to judge whether the predicted pressure rise time is the same as the delay time when a time difference between the predicted pressure rise time corresponding to the real-time pressure rising to the open valve threshold pressure and the delay time corresponding to the opening of the pressure relief valve is within a trigger time threshold range; and a signal generation subunit configured to record the real-time pressure at the corresponding time point and generate the pressure relief control signal when the predicted pressure rise time is the same as the delay time. The oil injection prediction unit comprises:

4. The pressure relief valve switch control system of claim 1, wherein, ​ a coefficient correction subunit configured to sequentially correct the initial flow characteristic coefficient according to the historical opening pressure when the pressure relief valve is actually opened, the historical closing pressure after the pressure relief valve is actually closed, and the valve closing threshold pressure corresponding to each of the historical injection periods in the order of the historical injection periods before and after the current injection period, to obtain a target flow characteristic coefficient corresponding to the current injection period; a data reading subunit configured to read the target flow characteristic coefficient according to the pressure relief control signal, and take the real-time pressure corresponding to the generation of the pressure relief control signal as the opening pressure of the current injection period; and a time length calculation subunit configured to predict an injection time length corresponding to the current injection period according to the target flow characteristic coefficient, the opening pressure, the valve closing threshold pressure, and the delay time. The calculation formula of the injection time length is: ； wherein, denotes the injection duration corresponding to the current injection cycle, denotes the target flow characteristic coefficient, denotes the opening pressure corresponding to the current injection cycle, denotes the closing threshold pressure, denotes the delay time, denotes the current injection cycle.

5. The pressure relief valve switch control system of claim 4, wherein, The coefficient correction subunit includes: an error calculation module configured to obtain a historical pressure error according to the historical closing pressure and the valve closing threshold pressure corresponding to each of the historical injection periods; and a coefficient calculation module configured to obtain the target flow characteristic coefficient corresponding to the current injection period according to the historical pressure error, a target dynamic adjustment factor, and the initial flow characteristic coefficient.

6. The pressure relief valve switch control system of claim 5, wherein, The calculation formula of the historical pressure error is: ； wherein, represents a history pressure error, represents a history closing pressure corresponding to the first history injection cycle, represents a valve closing threshold pressure; The calculation formula of the target flow characteristic coefficient is: ； wherein, represents a target flow characteristic coefficient, represents an initial flow characteristic coefficient, represents a target dynamic adjustment factor.

7. The pressure relief valve switch control system of claim 5, wherein, The coefficient calculation module includes: a characteristic inverse calculation module configured to obtain an actual value of a previous flow characteristic coefficient according to a previous historical closing pressure, a previous historical opening pressure, and a previous historical injection time length corresponding to a previous injection period; and a dynamic verification sub-module configured to predict the target dynamic adjustment factor corresponding to the current injection period according to a previous flow characteristic coefficient corresponding to the previous injection period, the actual value of the previous flow characteristic coefficient, the previous historical closing pressure, and the valve closing threshold pressure, so as to obtain the target flow characteristic coefficient corresponding to the current injection period according to the historical pressure error, the target dynamic adjustment factor, and the initial flow characteristic coefficient.

8. The pressure relief valve switch control system of claim 7, wherein, The calculation formula of the target dynamic adjustment factor is: ； wherein, represents a target dynamic adjustment factor, represents a previous flow characteristic coefficient actual value, represents a previous flow characteristic coefficient, represents a previous historical injection duration, represents a previous historical opening pressure, represents a previous historical closing pressure, represents a valve closing threshold pressure, represents a previous historical pressure error.

9. The pressure relief valve switch control system of claim 1, wherein, The injection control unit includes: a timing subunit configured to control the pressure relief valve to open according to the pressure relief control signal, and send the injection time length to a timer to control the timing of the timer through the injection time length; and a closing control subunit configured to generate a closing control signal to control the pressure relief valve to close when the timing of the timer ends.

10. A relief valve switch control method characterized by, It includes: obtaining a real-time pressure of a pressure relief valve through a pressure acquisition unit; generating a pressure relief trigger condition through a condition generation unit according to the real-time pressure, an opening threshold pressure, and a delay time corresponding to the opening and closing process of the pressure relief valve; detecting the real-time pressure according to the pressure relief trigger condition through a trigger detection unit, and generating a pressure relief control signal when the real-time pressure meets the pressure relief trigger condition; The oil injection prediction unit predicts an oil injection duration corresponding to the current oil injection cycle according to an initial flow characteristic coefficient and historical opening and closing pressures of the pressure relief valve corresponding to the historical oil injection cycle, wherein the initial flow characteristic coefficient is calibrated by oil medium under the same working condition at different test opening pressures and different test closing pressures corresponding to different test oil injection durations; The oil injection control unit controls the pressure relief valve to inject oil and then close the valve according to the pressure relief control signal and the oil injection duration.

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