A multi-channel gas flow rate proportional control method and system

Abstract

The present invention relates to a multi-channel gas flow ratio control method and system. The method includes: using flow sensors to respectively obtain the upstream flow rate and the flow rates in the secondary channels, and calculating the flow rate ratios in the secondary channels; setting the sum of the actual flow rate ratios in the secondary channels to 1 and the sum of the flow rate ratio set values in the secondary channels to 1; constructing an internal model control algorithm and combining it with a PID algorithm to dynamically adjust the control gain; when the set value changes, applying a voltage feedforward signal to all secondary channels to quickly approach the target ratio; monitoring the feedback errors and change rates of the secondary channels in real time, and dynamically adjusting the maximum channel priority according to the feedback errors and change rates; calculating the voltage values of the non-maximum channels, and driving the corresponding valves to adjust the opening degrees according to the voltage values. The present invention precisely controls the flow rate ratio through a control strategy combining PID control, voltage feedforward, and variable-speed gain, ensuring the stability and control accuracy of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of gas flow control, and particularly to a multi-channel gas flow ratio control method and system. Background Art

[0002] In the semiconductor manufacturing process, some process steps use one or more precursor gases, which react chemically in the reaction chamber to produce solid thin film materials and then deposit on the surface of the semiconductor wafer. For different precursor gases, it is necessary to accurately control their flow rates to ensure the accuracy and stability of the reaction. Especially in the chips with continuously improving manufacturing precision, any slight flow rate fluctuation may affect the thickness, uniformity, and electrical properties of the thin film. Therefore, the semiconductor industry has extremely high requirements for the accuracy and response speed of the gas flow ratio control system.

[0003] Currently, as Figure 1 shown, the existing flow ratio controller (FRC) uses the traditional PID algorithm combined with the logic of fully opening the maximum channel to perform channel ratio control through the mass flow controller (MFC). Due to the difference in the flow capacity of each channel valve, it is easy to cause the problem that when setting multiple identical or similar maximum ratio channels simultaneously, as Figures 2-4 shown, Figures 2-4 where the abscissa represents time and the ordinate represents the feedback ratio in both, there is a problem that the set ratio cannot be achieved; and during use, the traditional PID adjustment often has problems such as too slow adjustment speed or overshoot.

[0004] Therefore, it is necessary to provide a new multi-channel gas flow ratio control method and system. Summary of the Invention

[0005] Based on the above problems existing in the prior art, the purpose of the embodiments of the present invention is to provide a multi-channel gas flow ratio control method and system, which precisely controls the flow ratio through a multi-level control strategy combining PID control, voltage feedforward, and variable speed gain, so as to cope with the ratio fluctuation and overshoot problems caused by different valve flow capacities and adjustment speed differences, thereby ensuring the stability and control accuracy of the system.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: A multi-channel gas flow ratio control method, comprising:

[0007] S1, using a flow sensor to respectively obtain the upstream flow rate and the flow rate in the secondary channels and calculate the flow ratio in each secondary channel;

[0008] S2, set the sum of the actual flow ratios in each secondary channel to 1 and the sum of the set values of the flow ratios in each secondary channel to 1;

[0009] S3, construct an internal model control algorithm and combine it with a PID algorithm to dynamically adjust the control gain, suppress overshoot, and accelerate convergence;

[0010] S4, when the set value changes, apply a voltage feedforward signal to all secondary channels to quickly approach the target ratio;

[0011] S5, monitor the feedback error and change rate of each secondary channel in real time, and dynamically adjust the maximum channel priority according to the feedback error and change rate;

[0012] S6, calculate the non-maximum channel voltage value, and drive the corresponding valve to adjust the opening according to the voltage value.

[0013] Furthermore, the formula for the flow ratio in each secondary channel is:

[0014]

[0015] where, is the actual flow ratio of the corresponding i-channel relative to the upstream flow, is the actual flow through the i-channel, is the upstream flow.

[0016] Furthermore, the formula for setting the sum of the actual flow ratios in each secondary channel to 1 is:

[0017]

[0018] where, is the actual flow ratio of the corresponding i-channel relative to the upstream flow, is the actual flow ratio of the first secondary channel relative to the upstream flow, is the actual flow ratio of the second secondary channel relative to the upstream flow, is the actual flow ratio of the third secondary channel relative to the upstream flow, is the actual flow ratio of the fourth secondary channel relative to the upstream flow;

[0019] The formula for setting the sum of the set values of the flow ratios in each secondary channel to 1 is:

[0020]

[0021] where, is the set value of the flow ratio of the corresponding i-channel, is the set value of the flow ratio of the first secondary channel relative to the upstream flow, The set value of the flow rate ratio of the second secondary channel relative to the upstream flow rate The set value of the flow rate ratio of the third secondary channel relative to the upstream flow rate The set value of the flow rate ratio of the fourth secondary channel relative to the upstream flow rate.

[0022] Furthermore, constructing the internal model control algorithm and combining it with the PID algorithm to dynamically adjust the control gain, suppressing overshoot and accelerating convergence, includes:

[0023] Based on the system model and the internal model, the transfer function of the internal model controller is constructed as:

[0024]

[0025] Wherein, Is the transfer function of the closed-loop controller, Is the transfer function of the internal model controller, Is the internal model of the system;

[0026] Introduce a filter into the transfer function of the internal model controller Let Be The minimum-phase part of, then the design formula of the internal model controller is:

[0027]

[0028] Wherein, Is the transfer function of the internal model controller, Is the inverse of the system model (only taking the minimum-phase part), Is the low-pass filter;

[0029] The filter is And Is an adjustable parameter, and the value of r is selected according to the actual input.

[0030] Furthermore, constructing the internal model control algorithm and combining it with the PID algorithm to dynamically adjust the control gain, suppressing overshoot and accelerating convergence, further includes:

[0031] According to the transfer function of the internal model controller, establish the closed-loop system response equation as:

[0032]

[0033] Wherein, Is the actual flow rate ratio of the system output, Is the target flow rate ratio of the set value input, Is the external disturbance input, Is the disturbance transfer function, Is the transfer function of the closed-loop controller, is the system model;

[0034] Substituting the internal model controller transfer function, the closed-loop system response equation is further obtained as:

[0035]

[0036] where, is the actual flow rate ratio of the system output, is the target flow rate ratio of the set value input, is the external disturbance input, is the disturbance transfer function, is the internal model controller transfer function, is the system internal model, is the system model.

[0037] Furthermore, the real-time monitoring of the feedback error and change rate of each secondary channel, and dynamically adjusting the maximum channel priority according to the feedback error and change rate, includes:

[0038] Step S51, input the flow rate ratio set value 、the flow rate ratio feedback value , the error steady-state difference value 、the error change rate steady-state difference value and the single-channel full-open voltage ;

[0039] Step S52, when the flow rate ratio set value of a certain secondary channel is equal to the current maximum flow rate ratio set value , perform error detection and judgment;

[0040] Step S53, if within 10 consecutive sampling periods, the feedback error of this channel is less than the error steady-state difference value and the feedback error change rate of this channel is less than the error change rate steady-state difference value , then determine that this channel is stable and set it as the maximum channel; otherwise, sort the priorities of each secondary channel and select the secondary channel with the smallest error as the maximum channel;

[0041] Step S54, update the maximum secondary channel number to , and apply the single-channel full-open voltage to the maximum secondary channel, and calculate the voltage for the remaining channels according to the internal model control algorithm.

[0042] Furthermore, the calculation formula for the non-maximum channel voltage value is:

[0043]

[0044] where, is the non-maximum channel voltage value at time k, is the non-maximum channel voltage value at time k-1, is the flow rate ratio setting value of channel i at time k, is the transfer function of the closed-loop controller.

[0045] A multi-channel gas flow rate ratio control system is applied to the above multi-channel gas flow rate ratio control method. The system includes:

[0046] A data acquisition and calculation module for respectively acquiring the upstream flow rate and the flow rate in the secondary channels by using flow sensors and calculating the flow rate ratios in the secondary channels;

[0047] An initialization setting module for setting the sum of the actual flow rate ratios in the secondary channels to 1 and the sum of the flow rate ratio setting values in the secondary channels to 1;

[0048] An internal model control calculation module for constructing an internal model control algorithm and dynamically adjusting the control gain in combination with the PID algorithm to suppress overshoot and accelerate convergence;

[0049] A feedforward trigger control module for applying a voltage feedforward signal to all secondary channels when the set value changes to quickly approach the target ratio;

[0050] A channel reordering module for real-time monitoring of the feedback errors and change rates of the secondary channels and dynamically adjusting the maximum channel priority according to the feedback errors and change rates;

[0051] A channel voltage control module for calculating the non-maximum channel voltage value and driving the corresponding valve to adjust the opening degree according to the voltage value.

[0052] The present invention also provides a computer-readable storage medium, in which one or more instructions are stored. When the one or more instructions are executed by a processor, the above multi-channel gas flow rate ratio control method is implemented.

[0053] The present invention also provides an electronic device, including: a memory and a processor; at least one program instruction is stored in the memory; the processor loads and executes the at least one program instruction to implement the above multi-channel gas flow rate ratio control method.

[0054] The beneficial effects of the present invention are as follows: A method for multi-channel gas flow ratio control of the present invention includes: using flow sensors to respectively obtain the upstream flow rate and the flow rates in the secondary channels and calculating the flow rate ratios in the secondary channels; setting the sum of the actual flow rate ratios in the secondary channels to 1 and the sum of the set values of the flow rate ratios in the secondary channels to 1; constructing an internal model control algorithm and combining it with a PID algorithm to dynamically adjust the control gain, suppress overshoot, and accelerate convergence; when the set value changes, applying a voltage feed-forward signal to all secondary channels to quickly approach the target ratio; monitoring the feedback errors and change rates of the secondary channels in real time, and dynamically adjusting the maximum channel priority according to the feedback errors and change rates; calculating the voltage values of the non-maximum channels, and driving the corresponding valves to adjust the opening degrees according to the voltage values. The method for multi-channel gas flow ratio control of the present invention uses an internal model control algorithm and combines it with a feed-forward algorithm, greatly reducing the ratio fluctuations and overshoot problems caused by the differences in the flow capacities of the channels and the differences in the adjustment ratios, and greatly improving the stability and control accuracy of the system; the present invention adds an internal model control on the basis of a PID controller, solves the overshoot problem caused by a fixed PID gain, effectively improves the response speed of the system, and alleviates to a certain extent the ratio fluctuation problem caused by the differences in the adjustment speeds due to different adjustment ratios; re-ranking the channels according to the channel feedback ratios to ensure that the set ratio is achieved: judging whether to re-rank according to the monitoring feedback ratio adjustment speed and error, and after re-ranking, solving the problem that multiple similar or equal maximum set channels cannot reach the set ratio due to the flow capacity; the control strategy of the present invention has a fast response speed and a good synchronous control effect, achieving high-precision control of gas flow ratio distribution. It greatly improves the control quality and reliability of the system in applications such as semiconductor manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The present invention will be further described below in conjunction with the drawings and embodiments.

[0056] In the figures:

[0057] Figure 1 is the schematic diagram of the flow ratio controller mentioned in the background art of the present invention;

[0058] Figure 2 is the schematic diagram of the first type of flow rate adjustment that cannot reach the set ratio mentioned in the background art of the present invention;

[0059] Figure 3 is the schematic diagram of the second type of flow rate adjustment that cannot reach the set ratio mentioned in the background art of the present invention;

[0060] Figure 4 is the schematic diagram of the third type of flow rate adjustment that cannot reach the set ratio mentioned in the background art of the present invention;

[0061] Figure 5 Flowchart of the multi-channel gas flow ratio control method provided for the first embodiment of the present invention;

[0062] Figure 6 Block diagram of the control algorithm of the flow ratio control system provided for the first embodiment of the present invention;

[0063] Figure 7 Schematic diagram of the components of the controller provided for the first embodiment of the present invention;

[0064] Figure 8 Flowchart of adjusting the maximum channel priority provided for the first embodiment of the present invention;

[0065] Figure 9 Schematic diagram of the test results of the first method using the multi-channel gas flow ratio control method provided for the first embodiment of the present invention;

[0066] Figure 10 Schematic diagram of the test results of the second method using the multi-channel gas flow ratio control method provided for the first embodiment of the present invention;

[0067] Figure 11 Schematic diagram of the test results of the third method using the multi-channel gas flow ratio control method provided for the first embodiment of the present invention;

[0068] Figure 12 Schematic diagram of the modules of the multi-channel gas flow ratio control system provided for the second embodiment of the present invention;

[0069] Figure 13 Schematic diagram of the structure of the network-side server provided according to the third embodiment of the present invention. Specific embodiments

[0070] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0071] First embodiment:

[0072] The first embodiment of the present invention provides a method for multi-channel gas flow ratio control, including: respectively obtaining the upstream flow rate and the flow rates in the secondary channels by flow sensors and calculating the flow rate ratios in the secondary channels; setting the sum of the actual flow rate ratios in the secondary channels to 1 and the sum of the flow rate ratio set values in the secondary channels to 1; constructing an internal model control algorithm and combining it with a PID algorithm to dynamically adjust the control gain, suppress overshoot and accelerate convergence; when the set value changes, applying a voltage feedforward signal to all secondary channels to quickly approach the target ratio; monitoring the feedback errors and change rates of each secondary channel in real time and dynamically adjusting the maximum channel priority according to the feedback errors and change rates; calculating the voltage values of non-maximum channels and driving the corresponding valves to adjust the opening degrees according to the voltage values. The method for multi-channel gas flow ratio control of the present invention precisely controls the flow ratio through a multi-level control strategy combining PID control, voltage feedforward and variable speed gain to cope with the ratio fluctuations and overshoot problems caused by different valve flow capacities and adjustment speed differences, thereby ensuring the stability and control accuracy of the system.

[0073] The implementation details of the method for multi-channel gas flow ratio control in this embodiment are specifically described below. The following content is only the implementation details provided for convenient understanding and is not necessary for implementing this solution. The specific process of this embodiment is as Figure 5 shown.

[0074] Step S1: Use flow sensors to respectively obtain the upstream flow rate and the flow rates in the secondary channels and calculate the flow rate ratios in the secondary channels.

[0075] Specifically, the step of using flow sensors to respectively obtain the upstream flow rate and the flow rates in the secondary channels and calculate the flow rate ratios in the secondary channels includes the following steps:

[0076] Step S11: Use a gas mass flow sensor to obtain the upstream flow rate , use a gas mass flow sensor to obtain the actual flow rates in four secondary channels , , , .

[0077] Step S12: Calculate the relationship between the upstream flow rate and the flow rates in each secondary channel and verify the consistency of the upstream flow rate.

[0078] The upstream flow rate is calculated by the formula:

[0079]

[0080] where is the actual flow rate through channel i, is the upstream flow rate, is the actual flow rate through the first secondary channel, is the actual flow rate through the first secondary channel, is the actual flow rate through the third secondary channel, is the actual flow rate through the fourth secondary channel.

[0081] Through the upstream flow rate calculation formula, ensure that the upstream flow rate is the sum of the flow rates of each secondary channel, thereby verifying the consistency of flow rate distribution.

[0082] Step S13, calculate the actual flow rate ratio within each secondary channel to ensure the correct flow rate distribution logic.

[0083] The flow rate ratio calculation formula within each secondary channel is:

[0084]

[0085] where, is the actual flow rate ratio of the corresponding i-th channel relative to the upstream flow rate, is the actual flow rate through the i-th channel, is the upstream flow rate.

[0086] Step S2, set the sum of the actual flow rate ratios within each secondary channel to 1 and the sum of the set values of the flow rate ratios within each secondary channel to 1.

[0087] Specifically, the formula for setting the sum of the actual flow rate ratios within each secondary channel to 1 is:

[0088]

[0089] where, is the actual flow rate ratio of the corresponding i-th channel relative to the upstream flow rate, is the actual flow rate ratio of the first secondary channel relative to the upstream flow rate, is the actual flow rate ratio of the second secondary channel relative to the upstream flow rate, is the actual flow rate ratio of the third secondary channel relative to the upstream flow rate, is the actual flow rate ratio of the fourth secondary channel relative to the upstream flow rate.

[0090] Setting the sum of the actual flow rate ratios within each secondary channel to 1 ensures the logical correctness of flow rate distribution.

[0091] The formula for the sum of the set values of the flow rate ratios within each secondary channel to 1 is:

[0092]

[0093] where, is the set value of the flow rate ratio of the corresponding i-th channel, The set value of the flow rate ratio of the first secondary channel to the upstream flow rate The set value of the flow rate ratio of the second secondary channel to the upstream flow rate The set value of the flow rate ratio of the third secondary channel to the upstream flow rate The set value of the flow rate ratio of the fourth secondary channel to the upstream flow rate

[0094] Step S3: Construct an internal model control algorithm and combine it with a PID algorithm to dynamically adjust the control gain, suppress overshoot, and accelerate convergence.

[0095] Specifically, as Figure 6 、 Figure 7 shown, the construction of the internal model control algorithm and the combination with the PID algorithm to dynamically adjust the control gain, suppress overshoot, and accelerate convergence specifically includes the following steps:

[0096] Step S31: Based on the system model and the internal model, construct the transfer function of the internal model controller as:[[]]

[0097]

[0098] Wherein, Is the transfer function of the closed-loop controller, Is the transfer function of the internal model controller, Is the internal model of the system.

[0099] By constructing the transfer function of the internal model controller and combining the actual system model with the internal model, the control robustness is improved and external disturbances are suppressed.

[0100] Since Is difficult to obtain in an actual system (if Is an integral model, then As a differential link cannot exist alone), so the transfer function of the internal model controller A filter is introduced, and let Be The minimum-phase part of, then the design formula of the internal model controller is:[[]]

[0101]

[0102] Wherein, Is the transfer function of the internal model controller, Is the inverse of the system model (only taking the minimum-phase part), Is a low-pass filter.

[0103] The filter is And is an adjustable parameter, and the value of r is selected according to the actual input. By adjusting the parameters of the filter, the performance of the system can be improved, the stability of the system can be enhanced, and the ability to suppress high-frequency noise can be improved.

[0104] Step S32, expand the transfer function of the internal model controller into the PID form and match the parameters.

[0105] Specifically, expand the transfer function of the internal model controller into the PID form, match the proportional, integral, and differential term parameters. By combining the advantages of PID control, the system can control the flow more precisely, effectively suppress the overshoot phenomenon, accelerate the system convergence, and improve the control effect.

[0106] Step S33, according to the transfer function of the internal model controller, establish the closed-loop system response equation as:

[0107]

[0108] where, is the actual flow rate ratio of the system output, is the target flow rate ratio of the set value input, is the external disturbance input, is the disturbance transfer function, is the closed-loop controller transfer function, is the system model.

[0109] Substitute the transfer function of the internal model controller, and further obtain the closed-loop system response equation as:

[0110]

[0111] where, is the actual flow rate ratio of the system output, is the target flow rate ratio of the set value input, is the external disturbance input, is the disturbance transfer function, is the transfer function of the internal model controller, is the internal system model, is the system model.

[0112] Because , then it can be deduced by the final value theorem that in the case of infinity , so in the case of step response, even if an accurate model is not obtained, the output can track the target of the set value.

[0113] Realize dynamic adjustment of the control gain through the closed-loop system response equation. By continuously adjusting the gain, observe the actual flow rate ratio of the system output to the target flow rate ratio of the set value input The tracking situation is verified to check the tracking performance of the system and ensure that the system can quickly and accurately track the set value.

[0114] Step S4: When the set value changes, apply a voltage feedforward signal to all secondary channels to quickly approach the target ratio.

[0115] Specifically, when the current ratio of the channel with relatively weak current-carrying capacity in the channel is the same as the maximum ratio, the voltage of this channel will exceed the maximum voltage, resulting in a slower next adjustment.

[0116] As an example, the current-carrying capacity of channel #3 is relatively weak, and the current ratio is 5 / 5 / 45 / 45. At this time, the voltage of channel #3 is greater than. If the next set ratio is 45 / 5 / 5 / 45, channel #3 first has to cross the dead zone, resulting in slow adjustment; adding feedforward regulation ensures quickly crossing the valve dead zone and accelerating the system adjustment speed. Therefore, when it is detected that the set value changes, a full-open feedforward is given to all four channels simultaneously.

[0117] Step S5: Real-time monitor the feedback error and change rate of each secondary channel, and dynamically adjust the priority of the maximum channel according to the feedback error and change rate.

[0118] Specifically, as Figure 8 shown, the specific steps of real-time monitoring the feedback error and change rate of each secondary channel and dynamically adjusting the priority of the maximum channel according to the feedback error and change rate include:

[0119] Step S51: Input the flow ratio set value , the flow ratio feedback value , the steady-state error difference value , the steady-state difference value of the error change rate and the full-open voltage of a single channel .

[0120] Step S52: When the flow ratio set value of a certain secondary channel is equal to the current maximum flow ratio set value , perform error detection and judgment.

[0121] Step S53: If within 10 consecutive sampling periods, the feedback error of this channel is less than the steady-state error difference value and the change rate of the feedback error of this channel is less than the steady-state difference value of the error change rate , then determine that this channel is stable and set it as the maximum channel; otherwise, sort the priorities of each secondary channel and select the secondary channel with the smallest error as the maximum channel.

[0122] Step S54: Update the maximum secondary channel number to , and apply the full-open voltage of a single channel to the maximum secondary channel , that is is the single-channel fully open voltage; the voltages of the remaining channels are calculated according to the internal model control algorithm.

[0123] Step S6, calculate the voltage value of the non-maximum channel, and drive the corresponding valve to adjust the opening according to the voltage value.

[0124] Specifically, the calculation formula for the voltage value of the non-maximum channel is:

[0125]

[0126] where is the voltage value of the non-maximum channel at time k, is the voltage value of the non-maximum channel at time k-1, is the flow rate ratio setting value of channel i at time k, is the transfer function of the closed-loop controller.

[0127] A multi-channel gas flow rate ratio control method of the present invention includes: using flow sensors to respectively obtain the upstream flow rate and the flow rates in the secondary channels and calculate the flow rate ratios in the secondary channels; setting the sum of the actual flow rate ratios in the secondary channels to 1 and the sum of the flow rate ratio setting values in the secondary channels to 1; constructing an internal model control algorithm and combining it with a PID algorithm to dynamically adjust the control gain, suppress overshoot and accelerate convergence; when the set value changes, apply a voltage feedforward signal to all secondary channels to quickly approach the target ratio; monitor the feedback error and change rate of each secondary channel in real time, and dynamically adjust the maximum channel priority according to the feedback error and change rate; calculate the voltage value of the non-maximum channel, and drive the corresponding valve to adjust the opening according to the voltage value. As Figures 9-11 shown, Figures 9-11 in which the abscissa represents time and the ordinate represents the feedback ratio. The multi-channel gas flow rate ratio control method of the present invention uses an internal model control algorithm and combines a feedforward algorithm, which greatly weakens the ratio fluctuations and overshoot problems caused by the regulation speed differences brought about by the differences in the flow capacity of each channel and different regulation ratios, and greatly improves the stability and control accuracy of the system; the present invention adds an internal model control on the basis of a PID controller, solves the overshoot problem caused by a fixed PID gain, effectively improves the response speed of the system, and alleviates to a certain extent the ratio fluctuation problem caused by the regulation speed differences resulting from different regulation ratios; reorders the channels according to the channel feedback ratio to ensure that the set ratio is reached: determines whether to reorder according to the monitoring feedback ratio regulation speed and error, and solves the problem that multiple similar or equal maximum set channels cannot reach the set ratio due to the flow capacity after reordering; the control strategy of the present invention has a fast response speed and a good synchronous control effect, realizing high-precision control of gas flow rate ratio distribution. It greatly improves the control quality and reliability of the system in applications such as semiconductor manufacturing.

[0128] Second Embodiment:

[0129] As Figure 12 shown, the second embodiment of the present invention provides a multi-channel gas flow ratio control system, which includes: a data acquisition and calculation module 201, an initialization setting module 202, an internal model control calculation module 203, a feedforward trigger control module 204, a channel reordering module 205, and a channel voltage control module 206.

[0130] Specifically, the data acquisition and calculation module 201 is used to respectively obtain the upstream flow rate and the flow rate in the secondary channels by using flow sensors and calculate the flow rate ratios in the secondary channels; the initialization setting module 202 is used to set the sum of the actual flow rate ratios in the secondary channels to 1 and the sum of the flow rate ratio set values in the secondary channels to 1; the internal model control calculation module 203 is used to construct an internal model control algorithm and dynamically adjust the control gain in combination with the PID algorithm to suppress overshoot and accelerate convergence; the feedforward trigger control module 204 is used to apply a voltage feedforward signal to all secondary channels when the set value changes to quickly approach the target ratio; the channel reordering module 205 is used to monitor the feedback error and change rate of each secondary channel in real time and dynamically adjust the maximum channel priority according to the feedback error and change rate; the channel voltage control module 206 is used to calculate the non-maximum channel voltage value and drive the corresponding valve to adjust the opening according to the voltage value.

[0131] The multi-channel gas flow ratio control system further includes control valves and valve controllers. Each control valve is arranged to control the corresponding flow rate from the upstream inlet channel through the corresponding outlet channel. The valve controller is responsible for integrating the control algorithm, precisely controlling the flow rate of each channel to achieve the control ratio issued by the upper computer. The valve controller receives the feedback signal from the gas mass flow sensor in real time and generates a valve control signal through the control algorithm.

[0132] It is not difficult to find that this embodiment is a system embodiment corresponding to the first embodiment, and this embodiment can be implemented in cooperation with the first embodiment. The relevant technical details mentioned in the first embodiment are still valid in this embodiment. To avoid repetition, they will not be elaborated here. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied in the first embodiment.

[0133] It is worth mentioning that each module involved in this embodiment is a logical module. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or can be implemented by a combination of multiple physical units. In addition, in order to highlight the innovative part of the present invention, units not closely related to solving the technical problems proposed by the present invention are not introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0134] The third embodiment of the present invention relates to a network-side server, as Figure 13 shown, including at least one processor 302; and a memory 301 communicatively connected to the at least one processor 302; wherein, the memory 301 stores instructions executable by the at least one processor 302, and the instructions are executed by the at least one processor 302 to enable the at least one processor 302 to execute the above data processing method.

[0135] Among them, the memory 301 and the processor 302 are connected by a bus. The bus can include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors 302 and the memory 301 together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, so they will not be further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be an element or multiple elements, such as multiple receivers and transmitters, and provides a unit for communicating with various other devices on the transmission medium. The data processed by the processor 302 is transmitted on the wireless medium through the antenna. Further, the antenna also receives data and transmits the data to the processor 302.

[0136] The processor 302 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interface, voltage regulation, power management, and other control functions. And the memory 301 can be used to store the data used by the processor 302 when executing operations.

[0137] The fourth embodiment of the present invention relates to a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the method for multi-channel gas flow ratio control in the first embodiment.

[0138] That is, those skilled in the art can understand that all or part of the steps in the methods of the above embodiments can be completed by instructing relevant hardware through a program. The program is stored in a storage medium and includes several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0139] The above are only the embodiments of the present invention. Specific structures and common knowledge such as characteristics that are well-known in the art are not described in detail here. Those of ordinary skill in the art know all the common technical knowledge in the technical field to which the invention pertains before the filing date or the priority date, can know all the existing technologies in this field, and have the ability to apply conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in the present application, complete and implement this solution in combination with their own abilities. Some typical well-known structures or well-known methods should not be an obstacle for those of ordinary skill in the art to implement the present application. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by the present application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

[0140] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the ratio of multi-channel gas flow, characterized in that: include: S1, using a flow sensor to obtain the upstream flow and the flow in the secondary channel respectively and calculate the flow ratio in each secondary channel; S2, setting the sum of the actual flow ratios in each secondary channel to 1 and the sum of the flow ratio setting values ​​in each secondary channel to 1; S3, construct an internal model control algorithm and combine it with the PID algorithm to dynamically adjust the control gain to suppress overshoot and accelerate convergence; S4, when the set value changes, a voltage feed-forward signal is applied to all secondary channels to quickly approach the target ratio; S5, real-time monitoring of the feedback error and change rate of each secondary channel, and dynamically adjusting the maximum channel priority according to the feedback error and change rate, including: Step S51: Input the flow ratio setting value of each secondary channel , flow rate proportional feedback value , the error steady-state difference , steady-state difference value of error change rate and single channel full-on voltage ; Step S52: When the flow rate ratio setting value of a certain secondary channel is Equal to the current maximum flow rate ratio setting value When , error detection and judgment are performed; Step S53: If the feedback error of the channel is less than the error steady-state difference value within 10 consecutive sampling periods, And the feedback error change rate of the channel is less than the steady-state difference value of the error change rate , then the channel is determined to be stable and set as the maximum channel; otherwise, the secondary channels are sorted by priority and the secondary channel with the smallest error is selected as the maximum channel; Step S54, update the maximum secondary channel number to , and apply a single channel full-open voltage to the largest secondary channel , the voltage of the remaining channels is calculated according to the internal model control algorithm; S6, calculating the non-maximum channel voltage value, and driving the corresponding valve to adjust the opening according to the voltage value.

2. The method for multi-channel gas flow ratio control according to claim 1, characterized in that: The flow rate ratio calculation formula in each secondary channel is: in, is the actual flow ratio of channel i relative to the upstream flow, is the actual flow through channel i, is the upstream flow.

3. The method for multi-channel gas flow ratio control according to claim 1, characterized in that: The formula for setting the sum of the actual flow ratios in each secondary channel to 1 is: in, is the actual flow ratio of channel i relative to the upstream flow, is the actual flow ratio of the first secondary channel relative to the upstream flow, is the actual flow ratio of the second secondary channel relative to the upstream flow, is the actual flow ratio of the third secondary channel relative to the upstream flow, is the actual flow ratio of the fourth secondary channel relative to the upstream flow; The sum of the flow ratio setting values ​​in each secondary channel is 1, and the formula is: in, is the set value of the flow ratio corresponding to channel i, Set the flow ratio of the first secondary channel relative to the upstream flow. Set the flow ratio of the second secondary channel relative to the upstream flow. Set the flow ratio of the third secondary channel relative to the upstream flow. Sets the value for the flow ratio of the fourth secondary channel relative to the upstream flow.

4. The method for multi-channel gas flow ratio control according to claim 1, characterized in that: The internal model control algorithm is constructed and combined with the PID algorithm to dynamically adjust the control gain, suppress overshoot and accelerate convergence, including: Based on the system model and the internal model, the transfer function of the internal model controller is constructed as: in, is the closed-loop controller transfer function, is the internal model controller transfer function, is the internal model of the system; In the internal model controller transfer function The filter is introduced inside. for The minimum phase part in the internal model controller is: in, is the internal model controller transfer function, is the inverse of the system model (taking only the minimum phase part), is a low-pass filter; The filter is ,and It is an adjustable parameter, and the value of r is selected according to the actual input.

5. The method for multi-channel gas flow ratio control according to claim 4, characterized in that: The internal model control algorithm is constructed and combined with the PID algorithm to dynamically adjust the control gain, suppress overshoot and accelerate convergence, and also includes: According to the transfer function of the internal model controller, the closed-loop system response equation is established as: in, is the actual flow ratio of the system output, The target flow ratio for the setpoint input, is the external disturbance input, is the disturbance transfer function, is the closed-loop controller transfer function, is the system model; Substituting the internal model controller transfer function, the closed-loop system response equation is further obtained as: in, is the actual flow ratio of the system output, The target flow ratio for the setpoint input, is the external disturbance input, is the disturbance transfer function, is the internal model controller transfer function, is the internal model of the system, For the system model.

6. The method for multi-channel gas flow ratio control according to claim 1, characterized in that: The non-maximum channel voltage value calculation formula is: in, is the non-maximum channel voltage value at time k, is the non-maximum channel voltage value at time k-1, is the flow ratio setting value of channel i at time k, is the closed-loop controller transfer function.

7. A multi-channel gas flow ratio control system, characterized in that: The method for controlling the proportional flow of multi-channel gas according to any one of claims 1 to 6, wherein the system comprises: A data acquisition and calculation module, used to respectively obtain the upstream flow and the flow in the secondary channel using a flow sensor and calculate the flow ratio in each secondary channel; An initialization setting module is used to set the sum of the actual flow ratios in each secondary channel to 1 and the sum of the flow ratio setting values ​​in each secondary channel to 1; Internal model control calculation module, used to build the internal model control algorithm and dynamically adjust the control gain in combination with the PID algorithm to suppress overshoot and accelerate convergence; A feedforward trigger control module is used to apply a voltage feedforward signal to all secondary channels when the set value changes, so as to quickly approach the target ratio; The channel reordering module is used to monitor the feedback error and change rate of each secondary channel in real time, and dynamically adjust the maximum channel priority according to the feedback error and change rate. Specifically, it includes: inputting the flow ratio setting value of each secondary channel , flow rate proportional feedback value , the error steady-state difference , steady-state difference value of error change rate and single channel full-on voltage ; When the flow ratio setting value of a secondary channel Equal to the current maximum flow rate ratio setting value When , error detection and judgment are performed; If the feedback error of the channel is less than the steady-state difference value of the error within 10 consecutive sampling cycles And the feedback error change rate of the channel is less than the steady-state difference value of the error change rate , then the channel is determined to be stable and set as the maximum channel; otherwise, the secondary channels are sorted by priority and the secondary channel with the smallest error is selected as the maximum channel; Update the maximum secondary channel number to , and apply a single channel full-open voltage to the largest secondary channel , the voltage of the remaining channels is calculated according to the internal model control algorithm; The channel voltage control module is used to calculate the non-maximum channel voltage value and drive the corresponding valve to adjust the opening according to the voltage value.

8. A computer-readable storage medium, wherein at least one instruction is stored in the computer-readable storage medium, characterized in that: The instructions are executed by at least one processor to implement the multi-channel gas flow ratio control method described in any one of claims 1-6.

9. An electronic device, characterized in that: include: Memory and processor; At least one program instruction is stored in the memory; The processor implements the multi-channel gas flow ratio control method according to any one of claims 1 to 6 by loading and executing the at least one program instruction.

Images