Multi-channel gas flow proportion control method and system

Abstract

The invention relates to a multi-channel gas flow proportion control method and system, and the method comprises the steps: obtaining upstream flow and flow in secondary channels through a flow sensor, and calculating the flow proportion in each secondary channel; the sum of the actual flow proportions in the secondary channels is set to be 1, and the sum of the flow proportion set values in the secondary channels is set to be 1; constructing an internal model control algorithm and dynamically adjusting the control gain in combination with a PID algorithm; when a set value changes, voltage feed-forward signals are applied to all secondary channels, and a target proportion is quickly approached; monitoring the feedback error and the change rate of each secondary channel in real time, and dynamically adjusting the priority of the maximum channel according to the feedback error and the change rate; and calculating a non-maximum channel voltage value, and driving a corresponding valve to adjust the opening degree according to the voltage value. The flow proportion is accurately controlled through a control strategy combining PID control, voltage feedforward and variable speed gain, and the stability and the control precision of the system are ensured.

Description

Technical Field

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

[0002] In the semiconductor manufacturing process, some processes use one or more precursor gases, which produce solid thin film materials through chemical reactions in the reaction chamber and then deposit on the surface of the semiconductor wafer. For different precursor gases, it is necessary to be able to accurately control their flow to ensure the accuracy and stability of the reaction. Especially in the chips with increasing manufacturing precision, any slight flow fluctuation may affect the thickness, uniformity and electrical properties of the film. Therefore, the semiconductor industry has extremely high requirements for the accuracy and response speed of gas flow proportional control systems.

[0003] Currently, if Figure 1 As shown in the figure, the existing flow ratio controller (FRC) uses the traditional PID algorithm combined with the logic of the maximum channel fully open 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 multiple identical or similar maximum ratio channels to be set at the same time. Figure 2-4 As shown, Figure 2-4 The horizontal axis represents time, and the vertical axis represents feedback ratio. There is a problem that the set ratio cannot be reached; and during use, traditional PID regulation often has problems such as slow regulation speed or overshoot.

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

[0005] Based on the above-mentioned 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 to accurately control 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 the flow capacity and adjustment speed differences of different valves, thereby ensuring the stability and control accuracy of the system.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for controlling the proportional flow rate of a multi-channel gas, comprising: 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; S6, calculating the non-maximum channel voltage value, and driving the corresponding valve to adjust the opening according to the voltage value.

[0007] Furthermore, the flow rate ratio calculation formula in each secondary channel is:

[0008] 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.

[0009] Furthermore, the formula for setting the sum of the actual flow ratios in each secondary channel to 1 is:

[0010] 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:

[0011] 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.

[0012] Furthermore, 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:

[0013] 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:

[0014] 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.

[0015] Furthermore, the construction of the internal model control algorithm and the combination of the PID algorithm to dynamically adjust the control gain, suppress overshoot and accelerate convergence also include: According to the transfer function of the internal model controller, the closed-loop system response equation is established as:

[0016] 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:

[0017] 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.

[0018] Furthermore, the real-time monitoring of the feedback error and change rate of each secondary channel and the dynamic adjustment of the maximum channel priority according to the feedback error and change rate include: Step S51: Input the flow ratio setting value of each secondary channel , flow rate proportional feedback value , the error steady-state difference value , 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 , and the voltages of the remaining channels are calculated according to the internal model control algorithm.

[0019] Furthermore, the non-maximum channel voltage value calculation formula is:

[0020] 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.

[0021] A multi-channel gas flow ratio control system, applied to the multi-channel gas flow ratio control method, the system comprising: 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; 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.

[0022] The present invention also provides a computer-readable storage medium, wherein one or more instructions are stored in the computer-readable storage medium, and when a processor executes the one or more instructions, the method for multi-channel gas flow ratio control as described above is implemented.

[0023] The present invention also provides an electronic device, comprising: a memory and a processor; the memory stores at least one program instruction; the processor implements the above-mentioned method for multi-channel gas flow ratio control by loading and executing the at least one program instruction.

[0024] The beneficial effects of the present invention are as follows: a method for multi-channel gas flow ratio control of the present invention comprises: using a flow sensor to respectively obtain the upstream flow and the flow in the secondary channel and calculate the flow ratio in each secondary channel; setting the sum of the actual flow ratio in each secondary channel to 1 and the sum of the flow ratio setting values ​​in each secondary channel to 1; constructing an internal model control algorithm and dynamically adjusting the control gain in combination with the PID algorithm to 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; 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; calculating the non-maximum channel voltage value, and driving the corresponding valve to adjust the opening according to the voltage value. The method for controlling the ratio of multi-channel gas flow rate of the present invention uses an internal model control algorithm, combined with a feedforward algorithm, which greatly reduces the ratio fluctuation and overshoot caused by the difference in the flow capacity of each channel and the difference in the adjustment speed caused by the different adjustment ratios, and greatly improves the stability and control accuracy of the system; the present invention adds internal model control on the basis of the PID controller, solves the overshoot problem caused by the fixed PID gain, effectively improves the response speed of the system, and alleviates the ratio fluctuation problem caused by the difference in the adjustment speed caused by different adjustment ratios to a certain extent; the channels are reordered according to the channel feedback ratio to ensure that the set ratio is reached: the adjustment speed and error of the monitoring feedback ratio are determined to determine whether to reorder, and after reordering, the problem that multiple channels with similar or equal maximum settings cannot reach the set ratio due to the flow capacity is solved; the control strategy of the present invention has a fast response speed and a good synchronous control effect, and realizes high-precision control of the gas flow ratio distribution. The control quality and reliability of the system in applications such as semiconductor manufacturing are greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] In the figure: Figure 1 It is a schematic diagram of the flow ratio controller mentioned in the background technology of the present invention; Figure 2 It is a schematic diagram of the first type of flow regulation mentioned in the background technology of the present invention failing to reach the set ratio; Figure 3 It is a schematic diagram of the second flow regulation mentioned in the background technology of the present invention that fails to reach the set ratio; Figure 4 It is a schematic diagram of the third type of flow regulation mentioned in the background technology of the present invention that fails to reach the set ratio; Figure 5 A flow chart of a multi-channel gas flow ratio control method provided for a first embodiment of the present invention; Figure 6A flow rate proportional control system control algorithm block diagram provided by the first embodiment of the present invention; Figure 7 A schematic diagram of the components of a controller provided in the first embodiment of the present invention; Figure 8 A flowchart of adjusting the maximum channel priority provided by a first embodiment of the present invention; Fig. 9 A schematic diagram of test results of a first method for proportional control of multi-channel gas flow provided in a first embodiment of the present invention; Fig.10 A schematic diagram of test results of a second method for proportional control of multi-channel gas flow provided by the first embodiment of the present invention; Fig.11 A schematic diagram of test results of a third method for proportional control of multi-channel gas flow provided by the first embodiment of the present invention; Fig.12 A schematic diagram of a module for a multi-channel gas flow ratio control system provided in a second embodiment of the present invention; Fig.13 It is a schematic diagram of the structure of a network-side server provided according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] First embodiment: The first embodiment of the present invention provides a method for controlling the ratio of multi-channel gas flow, including: using a flow sensor to obtain the upstream flow and the flow in the secondary channel respectively and calculating the flow ratio in each secondary channel; setting the sum of the actual flow ratio in each secondary channel to 1 and the sum of the flow ratio setting value in each secondary channel to 1; constructing an internal model control algorithm and dynamically adjusting the control gain in combination with the PID algorithm to 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; real-time monitoring of the feedback error and change rate of each secondary channel, dynamically adjusting the maximum channel priority according to the feedback error and change rate; calculating the non-maximum channel voltage value, and driving the corresponding valve to adjust the opening according to the voltage value. The method for controlling the ratio of multi-channel gas flow of the present invention accurately controls the flow ratio through a multi-level control strategy combining PID control, voltage feedforward and variable speed gain to cope with the ratio fluctuation and overshoot problems caused by the flow capacity and adjustment speed differences of different valves, thereby ensuring the stability and control accuracy of the system.

[0029] The following is a detailed description of the implementation details of the multi-channel gas flow ratio control method of this embodiment. The following content is only for the convenience of understanding the implementation details, which is not necessary for the implementation of this solution. The specific process of this embodiment is as follows: Figure 5 shown.

[0030] Step S1, using a flow sensor to obtain the upstream flow and the flow in the secondary channel respectively and calculate the flow ratio in the secondary channel.

[0031] Specifically, the method of using a flow sensor to respectively obtain the upstream flow and the flow in the secondary channel and calculate the flow ratio in the secondary channel includes the following steps: Step S11, using a gas mass flow sensor to obtain the upstream flow , using gas mass flow sensors to obtain the actual flow in the four secondary channels , , , .

[0032] Step S12, calculating the relationship between the upstream flow and the flow of each secondary channel to verify the consistency of the upstream flow.

[0033] The upstream flow The calculation formula is:

[0034] in, is the actual flow through channel i, is the upstream flow, is the actual flow through the first secondary channel, is the actual flow through the first secondary channel, is the actual flow through the third secondary channel, is the actual flow through the fourth secondary channel.

[0035] Through the upstream flow calculation formula, it is ensured that the upstream flow is the sum of the flows of each secondary channel, thereby verifying the consistency of the flow distribution.

[0036] Step S13, calculating the actual flow ratio in each secondary channel to ensure that the flow distribution logic is correct.

[0037] The flow rate ratio calculation formula in each secondary channel is:

[0038] 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.

[0039] Step 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.

[0040] Specifically, the sum of the actual flow ratios in each secondary channel is set to 1. The formula is:

[0041] 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.

[0042] The sum of the actual flow ratios in each secondary channel is set to 1 to ensure the logical correctness of flow distribution.

[0043] The sum of the flow ratio setting values ​​in each secondary channel is 1. The formula is:

[0044] 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.

[0045] Step S3, constructing an internal model control algorithm and combining it with a PID algorithm to dynamically adjust the control gain, suppress overshoot and accelerate convergence.

[0046] Specifically, if Figure 6 , Figure 7 As shown, the construction of the internal model control algorithm and the dynamic adjustment of the control gain in combination with the PID algorithm to suppress overshoot and accelerate convergence specifically include the following steps: Step S31, based on the system model and the internal model, construct the internal model controller transfer function as:

[0047] in, is the closed-loop controller transfer function, is the internal model controller transfer function, It is the internal model of the system.

[0048] By constructing the internal model controller transfer function and combining the actual system model with the internal model, the control robustness is improved and external disturbances are suppressed.

[0049] because It is difficult to obtain in actual systems (if is an integral model, then As a differential link, it cannot exist alone), so the internal model controller transfer function The filter is introduced inside. for The minimum phase part in the internal model controller is:

[0050] 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.

[0051] The filter is ,and It 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.

[0052] Step S32: the internal model controller transfer function is expanded into a PID form and the parameters are matched.

[0053] Specifically, the transfer function of the internal model controller is expanded into a PID form, and the proportional, integral, and differential parameters are matched. By combining the advantages of PID control, the system can control the flow more accurately, effectively suppress overshoot, accelerate system convergence, and improve control effects.

[0054] Step S33, based on the internal model controller transfer function, a closed-loop system response equation is established:

[0055] 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, For the system model.

[0056] Substituting the internal model controller transfer function, the closed-loop system response equation is further obtained as:

[0057] 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.

[0058] because , then we can deduce from the final value theorem that in the infinite case Therefore, in the case of a step response, even if an accurate model is not obtained, the goal of output tracking the set value can be achieved.

[0059] The control gain is dynamically adjusted through the closed-loop system response equation. By continuously adjusting the gain, the actual flow ratio of the system output is observed. Target flow rate ratio to setpoint input Check the tracking status of the system to verify the tracking performance of the system and ensure that the system can track the set value quickly and accurately.

[0060] Step S4, when the set value changes, a voltage feedforward signal is applied to all secondary channels to quickly approach the target ratio.

[0061] Specifically, when the current ratio of a channel with weaker current-carrying capacity in the channel is consistent with the maximum ratio, the voltage of the channel will exceed the maximum voltage, causing the next regulation to be slower.

[0062] As an example, the flow capacity of channel #3 is weak, and the current ratio is 5 / 5 / 45 / 45. At this time, the voltage of channel #3 is greater than. If the next time the ratio is set to 45 / 5 / 5 / 45, channel #3 must first cross the dead zone, resulting in slow regulation; adding feedforward regulation ensures that the valve dead zone is quickly crossed and the system regulation speed is accelerated. Therefore, when a change in the set value is detected, full-open feedforward is performed on the four channels at the same time.

[0063] Step S5, monitoring the feedback error and change rate of each secondary channel in real time, and dynamically adjusting the maximum channel priority according to the feedback error and change rate.

[0064] Specifically, if Figure 8 As shown, the specific steps of 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 include: Step S51: Input the flow ratio setting value of each secondary channel , flow rate proportional feedback value , the error steady-state difference value , steady-state difference value of error change rate and single channel full-on voltage .

[0065] 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 the error detection is performed.

[0066] 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.

[0067] Step S54, update the maximum secondary channel number to , and apply a single channel full-open voltage to the largest secondary channel ,Right now is the fully open voltage of a single channel; the voltage of the remaining channels is calculated according to the internal model control algorithm.

[0068] Step S6, calculating the non-maximum channel voltage value, and driving the corresponding valve to adjust the opening according to the voltage value.

[0069] Specifically, the non-maximum channel voltage value calculation formula is:

[0070] 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.

[0071] The present invention provides a method for multi-channel gas flow ratio control, comprising: using flow sensors to obtain the upstream flow and the flow in the secondary channels respectively and calculating the flow ratio in each secondary channel; setting the sum of the actual flow ratio in each secondary channel to 1 and the sum of the flow ratio setting values ​​in each secondary channel to 1; constructing an internal model control algorithm and dynamically adjusting the control gain in combination with the PID algorithm to 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; 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; calculating the non-maximum channel voltage value, and driving the corresponding valve to adjust the opening according to the voltage value. Figure 9-11 As shown, Figure 9-11 The horizontal axis represents time, and the vertical axis represents feedback ratio. The method for multi-channel gas flow ratio control of the present invention uses an internal model control algorithm, combined with a feedforward algorithm, which greatly reduces the ratio fluctuation and overshoot caused by the difference in the flow capacity of each channel and the difference in the adjustment speed caused by the different adjustment ratios, and greatly improves the stability and control accuracy of the system; the present invention adds internal model control on the basis of the PID controller, solves the overshoot problem caused by the fixed PID gain, effectively improves the response speed of the system, and alleviates the ratio fluctuation problem caused by the difference in the adjustment speed caused by different adjustment ratios to a certain extent; the channels are reordered according to the channel feedback ratio to ensure that the set ratio is reached: the adjustment speed and error of the monitoring feedback ratio are determined to determine whether to reorder, and after reordering, the problem that multiple channels with similar or equal maximum settings cannot reach the set ratio due to the flow capacity is solved; the control strategy of the present invention has a fast response speed and a good synchronous control effect, and realizes high-precision control of the gas flow ratio distribution. The control quality and reliability of the system in applications such as semiconductor manufacturing are greatly improved.

[0072] Second implementation method: like Fig.12As shown, the second embodiment of the present invention provides a multi-channel gas flow ratio control system, the system comprising: a data acquisition 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.

[0073] Specifically, the data acquisition and calculation module 201 is used to use a flow sensor to respectively obtain the upstream flow and the flow in the secondary channel and calculate the flow ratio in each secondary channel; the initialization setting module 202 is used to set the sum of the actual flow ratio in each secondary channel to 1 and the sum of the flow ratio setting value in each secondary channel 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, so as 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.

[0074] The multi-channel gas flow ratio control system also includes a control valve and a valve controller. Each control valve is arranged to control the corresponding flow from the upstream inlet channel through the corresponding outlet channel. The valve controller is responsible for integrating the control algorithm, accurately controlling the flow of each channel to achieve the control ratio issued by the host computer, and 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.

[0075] 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 conjunction with the first embodiment. The relevant technical details mentioned in the first embodiment are still valid in this embodiment, and in order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the first embodiment.

[0076] It is worth mentioning that all modules involved in this embodiment are logic modules. In practical applications, a logic unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, in order to highlight the innovative part of the present invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by the present invention, but this does not mean that there are no other units in this embodiment.

[0077] A third embodiment of the present invention relates to a network side server, such as Fig.13As shown, it includes at least one processor 302; and a memory 301 that is communicatively connected to the at least one processor 302; wherein the memory 301 stores instructions that can be executed by the at least one processor 302, and the instructions are executed by the at least one processor 302 so that the at least one processor 302 can execute the above-mentioned data processing method.

[0078] The memory 301 and the processor 302 are connected in a bus manner, and the bus may 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 and are therefore not further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. The data processed by the processor 302 is transmitted on a wireless medium via an antenna, and further, the antenna also receives data and transmits the data to the processor 302.

[0079] The processor 302 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management and other control functions. The memory 301 can be used to store data used by the processor 302 when performing operations.

[0080] The fourth embodiment of the present invention relates to a computer-readable storage medium storing a computer program, which implements the method for multi-channel gas flow ratio control in the first embodiment when executed by a processor.

[0081] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0082] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles 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; 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 real-time monitoring of the feedback error and change rate of each secondary channel and the dynamic adjustment of the maximum channel priority according to the feedback error and change rate include: 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 , and the voltages of the remaining channels are calculated according to the internal model control algorithm.

7. The method for multi-channel gas flow ratio control according to claim 6, 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.

8. A multi-channel gas flow ratio control system, characterized in that: The method for controlling the ratio of multi-channel gas flow rate according to any one of claims 1 to 7, 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; 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.

9. 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 1-7.

10. An electronic device, characterized in that: include: A memory and a processor; the memory stores at least one program instruction; The processor implements the multi-channel gas flow ratio control method according to any one of claims 1 to 7 by loading and executing the at least one program instruction.

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