A method for controlling and correcting chatter in electromagnetic valves based on the L9305 chip.

Abstract

This invention relates to the field of solenoid valve control technology, and particularly to a solenoid valve chatter control method and its correction method based on the L9305 chip. The valve chatter control method includes the following steps: obtaining F_req and F_theo; determining whether F_theo meets the range requirements of F_req; if it does, executing S3; if not, executing S4; temporarily storing the Nstep that meets the requirements, and the Tstep corresponding to Nstep; determining whether the indexing is complete; if complete, executing to obtain Tstep; if not complete, determining and indexing; calculating Istep; S7, synchronizing SPI instructions and inputting Nstep, Tstep, and Istep into the L9305 chip to realize the chatter control of the solenoid valve. This invention achieves solenoid valve chatter control by first looking up a table and indexing to obtain the maximum current step change number Nstep, then the step time length Tstep corresponding to the maximum current step change number Nstep, and finally obtaining the current change amount Istep for each step, thereby improving the accuracy of solenoid valve chatter control.

Description

Technical Field

[0001] This invention relates to the field of solenoid valve control technology, and in particular to a solenoid valve chatter control method and its correction method based on the L9305 chip. Background Technology

[0002] A solenoid valve is an industrial device used for electromagnetic control. It is a fundamental component of automation systems used to control fluids and belongs to the actuator category. While not limited to hydraulic or pneumatic systems, it is primarily used in industrial control systems to adjust the direction, flow rate, speed, and other parameters of the medium. A solenoid valve consists of an electromagnetic coil and a valve body. Its main principle is to use the electromagnetic force generated by the coil to actuate the valve core, thereby controlling the flow of fluid. In the field of solenoid valve control, particularly in linear solenoid valves in automatic transmissions, electronic stability control, and active suspension systems, the chatter function plays a crucial role in reducing initial motion resistance, improving dynamic response, enhancing system stability, and avoiding viscous friction between the valve core and valve sleeve. In electro-hydraulic proportional control systems, real-time adjustment of the chatter signal is essential for ensuring the stability and reliability of hydraulic pressure control. The inductive reactance and impedance of the solenoid valve are important factors affecting chatter control, as they influence the change in current in the coil, thus affecting the precise control of the chatter signal. Therefore, we need to provide a solenoid valve chatter control method and its correction method based on the L9305 chip.

[0003] Currently, chatter control of solenoid valves relies on hardware improvements and PID control strategies. While these methods are effective in reducing chatter, they have limitations in precisely controlling chatter (i.e., the lack of precise chatter detection and analysis methods leads to imprecise chatter control) and correcting chatter (i.e., chatter correction strategies are not flexible enough and cannot adapt to different working conditions and system changes). Especially under complex operating conditions, the influence of the solenoid valve's inductive reactance and impedance on chatter control is not fully considered and effectively controlled, making it difficult to guarantee the accuracy of chatter control. In addition, the system's response and dynamic characteristics also affect the accuracy of chatter amplitude control. Electromagnetic interference and signal noise can also affect the transmission and execution of chatter signals, leading to inaccurate chatter amplitude control. The stability of the power supply and drive circuit can also lead to inaccurate chatter signal amplitude control, thus limiting the practical application of hardware improvements and PID control strategies. Summary of the Invention

[0004] To address the shortcomings of the existing production technology, the applicant provides a structurally sound electromagnetic valve chatter control method and correction method based on the L9305 chip. By improving the electromagnetic valve chatter control and correction methods, the control and correction accuracy of electromagnetic valve chatter can be improved.

[0005] The technical solution adopted in this invention is as follows:

[0006] A method for controlling chatter in an electromagnetic valve based on an L9305 chip includes the following steps:

[0007] S1. Obtain the requested chatter frequency value F_req and the theoretically calculated chatter frequency value F_theo for the required chatter control solenoid valve;

[0008] S2. Obtain the requested flutter frequency value F_req and the theoretically calculated flutter frequency value F_theo from S1, and determine whether the theoretically calculated flutter frequency value F_theo meets the range requirement of the requested flutter frequency value F_req according to the judgment formula. If it meets the requirement, proceed to S3; otherwise, proceed to S4.

[0009] S3. Temporarily store the current step change number Nstep of the L9305 chip dithering that meets the requirements, and the step time length Tstep of each step of the L9305 chip dithering corresponding to the current step change number Nstep.

[0010] S4. Determine if the indexing is complete. If complete, execute S5. If not complete, repeat S2 and S3 until the indexing is complete.

[0011] S5. Obtain the multiple current step change numbers Nstep in S3, find the maximum current step change number Nstep among the multiple current step change numbers Nstep, and then obtain the step time length Tstep corresponding to the maximum current step change number Nstep.

[0012] S6. Calculate the current change Istep for each step of L9305 chip dizziness based on the sent amplitude Amplitude and the maximum current step change Nstep in S5.

[0013] S7. Synchronize the SPI command and input the maximum current step change number Nstep, the step time length Tstep corresponding to the maximum current step change number Nstep, and the current change amount Istep of each step into the L9305 chip to realize the chatter control of the solenoid valve.

[0014] Therefore, the chatter control of the solenoid valve is achieved by first looking up a table and indexing to obtain the maximum current step change number Nstep, then determining the step time length Tstep corresponding to the maximum current step change number Nstep, and finally obtaining the current change amount Istep for each step. Compared with existing hardware improvements and PID control strategies, this method can accurately control the drive current and optimize the control algorithm. In addition, without increasing additional hardware costs, it can improve the accuracy of solenoid valve chatter control and correction control, thereby improving system stability and solenoid valve lifespan.

[0015] Furthermore, in S1, the formula for calculating the theoretically calculated flutter frequency value F_theo is:

[0016]

[0017] The unit of Nstep is Hz.

[0018] Furthermore, for S2, the judgment formula is:

[0019] F_req(1-K1)≤F_theo≤F_req(1+K1);

[0020] Where: K1 is the preset value.

[0021] Furthermore, in S6, the formula for calculating each step current change Istep is:

[0022]

[0023] Where: Amplitude is measured in mA.

[0024] Furthermore, in S1, the theoretically calculated chatter frequency value F_theo is obtained through a lookup table of chatter frequency control parameters; in S3, the current step change number Nstep and the length of each step time Tstep are both obtained through a lookup table of chatter frequency control parameters.

[0025] A modified method for electromagnetic valve chatter control based on the L9305 chip includes the following steps:

[0026] Sd, based on the current amplitude Amp_actual, the requested chatter frequency value F_req, and the chatter frequency threshold F_th of the dynamic compensation logic, obtains the corrected current amplitude Amp_actual_corr;

[0027] Se, based on the current amplitude Amp_actual, obtain the corrected current amplitude Amp_actual_corr;

[0028] Sf: Determine whether the corrected current amplitude Amp_actualA is less than the requested amplitude Amp_rep. If so, increment the current change Istep by 1 unit for each step. If not, decrement the current change Istep by 1 unit for each step.

[0029] Sg, obtain Istep_cal, request the chatter frequency value F_req, the chatter frequency threshold F_th of the dynamic compensation logic, and the change amount Istep of each step current. Then, determine whether the change amount Istep of each step current meets the requirements according to the judgment formula. If it does, execute Sh.

[0030] Sh, determine whether the change in current Istep for each step meets the requirements according to the judgment formula. If it does, then execute Si.

[0031] Si, input each step current change Istep into the L9305 chip to achieve corrective control of the solenoid valve.

[0032] Furthermore, in Sb, the formula for calculating the current amplitude Amp_actual is:

[0033] Amp_actual=I max -I min ;

[0034] Where: Current amplitude Amp_actual, maximum current value I max Minimum current value I min The average unit is mA.

[0035] Furthermore, in Sd, the formula for calculating the corrected current amplitude Amp_actual_corr is:

[0036]

[0037] In Se, the formula for calculating the corrected current amplitude Amp_actual_corr is:

[0038] Amp_actual_corr=Amp_actual.

[0039] Furthermore, in Sg, the judgment formula is:

[0040]

[0041] Where: K2 is the preset value.

[0042] Furthermore, in Sh, the judgment formula is:

[0043] 0 ≤ Istep ≤ 255.

[0044] The beneficial effects of this invention are as follows:

[0045] This invention achieves solenoid valve chatter control by first looking up a table and indexing to obtain the maximum current step change number Nstep, then determining the step time length Tstep corresponding to the maximum current step change number Nstep, and finally obtaining the current change amount Istep for each step. Compared to existing hardware improvements and PID control strategies, this method can accurately control the drive current and optimize the control algorithm. Furthermore, without increasing additional hardware costs, it can improve the accuracy of solenoid valve chatter control and correction control, thereby improving system stability and solenoid valve lifespan. Attached Figure Description

[0046] Figure 1 The flowchart shows the electromagnetic valve chatter control method based on the L9305 chip of the present invention.

[0047] Figure 2 This is a flowchart of the modified method of the electromagnetic valve chatter control method based on the L9305 chip of the present invention;

[0048] Figure 3 This is a schematic diagram of the beat time axis of the correction method of the electromagnetic valve chatter control method based on the L9305 chip of the present invention. Detailed Implementation

[0049] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0050] like Figure 1 As shown, a method for controlling the chatter of an electromagnetic valve based on the L9305 chip includes the following steps:

[0051] S1. Obtain the requested chatter frequency value F_req (Frequency request) and the theoretically calculated chatter frequency value F_theo for the required chatter control solenoid valve;

[0052] S2. Obtain the requested flutter frequency value F_req and the theoretically calculated flutter frequency value F_theo from S1, and determine whether the theoretically calculated flutter frequency value F_theo meets the range requirement of the requested flutter frequency value F_req according to the judgment formula. If it meets the requirement, proceed to S3; otherwise, proceed to S4.

[0053] S3. Temporarily store the current step change number Nstep of the L9305 chip dithering that meets the requirements, and the step time length Tstep of each step of the L9305 chip dithering corresponding to the current step change number Nstep.

[0054] S4. Determine if the indexing is complete. If complete, execute S5. If not complete, repeat S2 and S3 until the indexing is complete.

[0055] S5. Obtain the multiple current step change numbers Nstep in S3, find the maximum current step change number Nstep among the multiple current step change numbers Nstep, and then obtain the step time length Tstep corresponding to the maximum current step change number Nstep.

[0056] S6. Calculate the current change Istep for each step of L9305 chip dizziness based on the sent amplitude Amplitude and the maximum current step change Nstep in S5.

[0057] S7. Synchronize the SPI command and input the maximum current step change number Nstep, the corresponding step time length Tstep, and the current change amount Istep into the L9305 chip to achieve solenoid valve chatter control. Thus, by first looking up the table and indexing to obtain the maximum current step change number Nstep, then obtaining the corresponding step time length Tstep, and finally obtaining the current change amount Istep, solenoid valve chatter control is achieved. Compared to existing hardware improvements and PID control strategies, this method can precisely control the drive current and optimize the control algorithm. Furthermore, without increasing additional hardware costs, it can improve the accuracy of solenoid valve chatter control, thereby improving system stability and solenoid valve lifespan.

[0058] In other words, by looking up a table and indexing to obtain the maximum current step change quantity, and combining it with the duration of each step, the chatter frequency and amplitude of the solenoid valve can be precisely controlled. This allows for fine adjustment of the solenoid valve current, ensuring accurate generation of the chatter signal. By dynamically adjusting the current step change quantity and step time, real-time correction of the solenoid valve's chatter behavior is achieved. This dynamic adjustment mechanism makes control more flexible and adaptable to different operating conditions and system changes. Compared to existing hardware improvements and PID control strategies, this method improves the solenoid valve's response speed and reduces inaccurate chatter control caused by slow current changes. Rapid response capability is particularly important for control systems requiring quick adjustments. This method includes real-time detection and correction of the solenoid valve current, enabling timely detection and adjustment of deviations in chatter control, ensuring the solenoid valve always operates at its optimal state.

[0059] It should be noted that: 1. Since the theoretically calculated chatter frequency value F_theo obtained by calculating the current step change number Nstep and the step time length Tstep is consistent with the chatter frequency value obtained by actual testing with an oscilloscope, i.e., no chatter frequency compensation is required, it is more reasonable to first determine the current step change number Nstep and the step time length Tstep corresponding to the chatter frequency, and then use the current step change number Nstep and the requested value to calculate the current change amount Istep for each step, and then perform dynamic correction of the amplitude. Conversely, if the chatter requested amplitude is calculated first, the corresponding parameters, the current step change number Nstep and the step time length Tstep, are dynamically changing, which will cause the theoretical chatter frequency calculated by the current step change number Nstep and the step time length Tstep to fluctuate, which will make the chatter control accuracy worse.

[0060] 2. The L9305 chip is a solenoid valve control chip. The L9305 chip has hardware closed-loop current control and dither control functions.

[0061] 3. The range of the current step change number Nstep is [0, 31], which defines the number of current step changes within a quarter flutter cycle;

[0062] 4. The range of each step time length Tstep is [0, 63], which defines the time length of each step in the flutter waveform, that is, the time interval from one step to the next step;

[0063] 5. The range of each step current change Istep is [0, 255], which defines the current change for each step in the Dither waveform;

[0064] 6. SPI: Serial Peripheral Interface, is a high-speed, full-duplex, synchronous communication bus.

[0065] In this embodiment, in S1, the formula for calculating the theoretically calculated flutter frequency value F_theo is:

[0066]

[0067] The unit of Nstep is Hz.

[0068] In this embodiment, in S2, the determination formula is:

[0069] F_req(1-K1)≤F_theo≤F_req(1+K1);

[0070] Wherein: K1 is a preset value. For example, K1 = 5%, which means that as long as the found F_theo is within ±5% of the required dithering frequency, the corresponding current step change Nstep and the length of each step Tstep are considered valid values.

[0071] In this embodiment, in S6, the calculation formula for each step current change Istep is:

[0072]

[0073] Where: Amplitude is measured in mA.

[0074] In this embodiment, in S1, the theoretically calculated chatter frequency value F_theo is obtained through a chatter frequency control parameter lookup table; in S3, the current step change number Nstep and the length of each step time Tstep are both obtained through a chatter frequency control parameter lookup table.

[0075] Table 1: Flutter Frequency Control Parameter Lookup Table

[0076]

[0077]

[0078] like Figures 2 to 3 As shown, a modified method for electromagnetic valve chatter control based on the L9305 chip includes the following steps:

[0079] Sa: Obtain the current of the solenoid valve and determine whether the current of the solenoid valve has reached the specified cycle time. If it has reached the specified cycle time, execute Sb.

[0080] Sb, synchronously read the current sampling value of the L9305 chip, and calculate the maximum current value I read within one valve vibration cycle. max Minimum current value I min Then, the current amplitude Amp_actual obtained from the L9305 chip is calculated.

[0081] Sc: Obtain the requested chatter frequency value F_req of the required chatter control solenoid valve and the chatter frequency threshold F_th of the dynamic compensation logic, and determine the relationship between the two. If F_req > F_th, then execute Sd; if F_req ≤ F_th, then execute Se.

[0082] Sd, based on the current amplitude Amp_actual, the requested chatter frequency value F_req, and the chatter frequency threshold F_th of the dynamic compensation logic, obtains the corrected current amplitude Amp_actual_corr;

[0083] Se, based on the current amplitude Amp_actual, obtain the corrected current amplitude Amp_actual_corr;

[0084] Sf: Determine whether the corrected current amplitude Amp_actualA is less than the requested amplitude Amp_rep. If so, increment the current change Istep by 1 unit for each step. If not, decrement the current change Istep by 1 unit for each step.

[0085] Sg, obtain Istep_cal, request the chatter frequency value F_req, the chatter frequency threshold F_th of the dynamic compensation logic, and the change amount Istep of each step current. Then, determine whether the change amount Istep of each step current meets the requirements according to the judgment formula. If it does, execute Sh.

[0086] Sh, determine whether the change in current Istep for each step meets the requirements according to the judgment formula. If it does, then execute Si.

[0087] Si, input each step current change Istep into the L9305 chip to achieve corrective control of the solenoid valve.

[0088] It should be noted that: 1. In Sa, as shown in Figures, reaching the specified timeframe means that the code corresponding to the correction method is executed in a loop within a 200us cycle Task and at a fixed timeframe. SPI current sampling is performed at each timeframe. Uneven timeframes are more likely to hit the maximum and minimum current values.

[0089] 2. In Sc, when F_req > F_theo (i.e., during high-frequency flutter), it is not easy to hit the maximum and minimum current values, resulting in an underestimation of the amplitude. In this case, coefficient compensation is required.

[0090] 3. In Sf, control the range of dynamic correction parameters to avoid significant deviations from theoretical calculation results;

[0091] 4. The chatter frequency threshold of the F_th dynamic compensation logic, in Hz;

[0092] 5. Istep_cal, Istep calibration, is used to limit the range of Istep in amplitude dynamic range adjustment and can be used for calibration;

[0093] 6. Amp_actual_corr: Actual correction of amplitude.

[0094] In this embodiment, the formula for calculating the current amplitude Amp_actual in Sb is:

[0095] Amp_actual=I max -I min ;

[0096] Where: Current amplitude Amp_actual, maximum current value I max Minimum current value I min The average unit is mA.

[0097] In this embodiment, the formula for calculating the corrected current amplitude Amp_actual_corr in Sd is:

[0098]

[0099] In Se, the formula for calculating the corrected current amplitude Amp_actual_corr is:

[0100] Amp_actual_corr=Amp_actual.

[0101] In this embodiment, the determination formula in Sg is:

[0102]

[0103] Wherein: K2 is a preset value. For example, K2 = 10%.

[0104] In this embodiment, the determination formula in Sh is:

[0105] 0 ≤ Istep ≤ 255.

[0106] In summary, this invention achieves solenoid valve chatter control by first looking up a table and indexing to obtain the maximum current step change number Nstep, then determining the step time length Tstep corresponding to the maximum current step change number Nstep, and finally obtaining the current change amount Istep for each step. Compared to existing hardware improvements and PID control strategies, this method can accurately control the drive current and optimize the control algorithm. Furthermore, without increasing additional hardware costs, it can improve the accuracy of solenoid valve chatter control and correction control, thereby improving system stability and solenoid valve lifespan.

[0107] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A method for controlling chattering in an electromagnetic valve based on an L9305 chip, characterized in that: Includes the following steps: S1. Obtain the requested chatter frequency value F_req and the theoretically calculated chatter frequency value F_theo for the required chatter control solenoid valve; S2. Obtain the requested flutter frequency value F_req and the theoretically calculated flutter frequency value F_theo from S1, and determine whether the theoretically calculated flutter frequency value F_theo meets the range requirement of the requested flutter frequency value F_req according to the judgment formula. If it meets the requirement, proceed to S3; otherwise, proceed to S4. S3. Temporarily store the current step change number Nstep of the L9305 chip dithering that meets the requirements, and the step time length Tstep of each step of the L9305 chip dithering corresponding to the current step change number Nstep. S4. Determine if the indexing is complete. If complete, execute S5. If not complete, repeat S2 and S3 until the indexing is complete. S5. Obtain the multiple current step change numbers Nstep in S3, find the maximum current step change number Nstep among the multiple current step change numbers Nstep, and then obtain the step time length Tstep corresponding to the maximum current step change number Nstep. S6. Calculate the current change Istep for each step of L9305 chip dizziness based on the sent amplitude Amplitude and the maximum current step change Nstep in S5. S7. Synchronize the SPI command and input the maximum current step change number Nstep, the step time length Tstep corresponding to the maximum current step change number Nstep, and the current change amount Istep of each step into the L9305 chip to realize the chatter control of the solenoid valve.

2. The electromagnetic valve chatter control method based on the L9305 chip as described in claim 1, characterized in that: In S1, the formula for calculating the theoretically calculated flutter frequency value F_theo is: The unit of Nstep is Hz.

3. The electromagnetic valve chatter control method based on the L9305 chip as described in claim 1, characterized in that: S2, the judgment formula is: F_req(1-K1)≤F_theo≤F_req(1+K1); Where: K1 is the preset value.

4. The electromagnetic valve chatter control method based on the L9305 chip as described in claim 1, characterized in that: In S6, the formula for calculating each step current change Istep is: Where: Amplitude is measured in mA.

5. The electromagnetic valve chatter control method based on the L9305 chip as described in claim 1, characterized in that: In S1, the theoretically calculated flutter frequency value F_theo is obtained by looking up the flutter frequency control parameter value table; In S3, the number of current step changes Nstep and the duration of each step Tstep are obtained through a lookup table of chatter frequency control parameters.

6. A modified method for the electromagnetic valve chatter control method based on the L9305 chip as described in any one of claims 1-5, characterized in that: Includes the following steps: Sa: Obtain the current of the solenoid valve and determine whether the current of the solenoid valve has reached the specified cycle time. If it has reached the specified cycle time, execute Sb. Sb, synchronously read the current sampling value of the L9305 chip, and calculate the maximum current value I read within one valve vibration cycle. max Minimum current value I min Then, the current amplitude Amp_actual obtained from the L9305 chip is calculated. Sc: Obtain the requested chatter frequency value F_req of the required chatter control solenoid valve and the chatter frequency threshold F_th of the dynamic compensation logic, and determine the relationship between the two. If F_req > F_th, then execute Sd; if F_req ≤ F_th, then execute Se. Sd, based on the current amplitude Amp_actual, the requested chatter frequency value F_req, and the chatter frequency threshold F_th of the dynamic compensation logic, obtains the corrected current amplitude Amp_actual_corr; Se, based on the current amplitude Amp_actual, obtain the corrected current amplitude Amp_actual_corr; Sf: Determine whether the corrected current amplitude Amp_actualA is less than the requested amplitude Amp_rep. If so, increment the current change Istep by 1 unit for each step. If not, decrement the current change Istep by 1 unit for each step. Sg, obtain Istep_cal, request the chatter frequency value F_req, the chatter frequency threshold F_th of the dynamic compensation logic, and the change amount Istep of each step current. Then, determine whether the change amount Istep of each step current meets the requirements according to the judgment formula. If it does, execute Sh. Sh, determine whether the change in current Istep for each step meets the requirements according to the judgment formula. If it does, then execute Si. Si, input each step current change Istep into the L9305 chip to achieve corrective control of the solenoid valve.

7. The modified method of the solenoid valve chatter control method based on the L9305 chip as described in claim 6, characterized in that: In Sb, the formula for calculating the current amplitude Amp_actual is: Amp_actual=I max -I min ; Where: Current amplitude Amp_actual, maximum current value I max Minimum current value I min The average unit is mA.

8. The modified method of the solenoid valve chatter control method based on the L9305 chip as described in claim 6, characterized in that: In Sd, the formula for calculating the corrected current amplitude Amp_actual_corr is: In Se, the formula for calculating the corrected current amplitude Amp_actual_corr is: Amp_actual_corr=Amp_actual.

9. The modified method of the solenoid valve chatter control method based on the L9305 chip as described in claim 6, characterized in that: In Sg, the judgment formula is: Where: K2 is the preset value.

10. The modified method of the solenoid valve chatter control method based on the L9305 chip as described in claim 6, characterized in that: In Sh, the judgment formula is: 0 ≤ Istep ≤ 255.

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