A closed-loop feedback control system for numerically controlled valves

Abstract

This invention discloses a closed-loop feedback control CNC valve control system, relating to the field of CNC valve control. The system includes: a central controller, a base controller, a human-machine interface module, and a feedback execution module. The central controller is connected to both the base controller and the human-machine interface module. The feedback execution module is connected to both the base controller and the central controller. The human-machine interface module is used to input the control target value of the pipeline valve. The central controller receives the control target value from the human-machine interface module and the feedback data from the pipeline valve collected by the feedback execution module, and calculates the control quantity of the pipeline valve using a feedback control algorithm based on the control target value and the feedback data. The base controller applies the control quantity to the pipeline valve. The feedback execution module detects the state of the pipeline valve in real time and obtains feedback data. This invention enables precise control of the pipeline valve, thereby achieving precise control of the flow rate and velocity of the pipeline system.

Description

Technical Field

[0001] The invention relates to the field of numerical control valve control, and in particular to a numerical control valve control system with closed-loop feedback control. Background Art

[0002] The existing valve piping systems on the market generally use simple switch control for valve control, and the control accuracy is low, making it difficult to achieve high-precision integrated control. For some application scenarios with high requirements for flow control or rate control, they are only achieved by adding a flow quality controller to the piping system. The entire control system appears to be inconsistent, and application scenarios with high requirements for valve rotation position or torque cannot be achieved.

[0003] In the existing embodiments, such as the embodiment with publication number "CN 107035904A" and name "Automatic valve system driven by a double-acting pneumatic actuator capable of providing double protection", it mainly relates to a valve system driven by a double-acting pneumatic actuator capable of providing double protection and automatically opening or closing when the pressure exceeds a set value. It mainly targets the problem of switching the automatic valve, and does not involve the problem of precise control of the flow and flow rate of the pipeline system based on the valve. Summary of the invention

[0004] Based on this, an embodiment of the present invention provides a closed-loop feedback controlled numerical control valve control system to achieve precise control of pipeline valves, thereby achieving precise control of the pipeline valves over the flow and flow rate of the pipeline system.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A closed-loop feedback-controlled numerical control valve control system, comprising: a central controller, a grassroots controller, a human-computer interaction module and a feedback execution module;

[0007] The central controller is connected to the grassroots controller and the human-computer interaction module respectively; the feedback execution module is connected to the grassroots controller and the central controller respectively;

[0008] The human-computer interaction module is used to:

[0009] A control target value of the input pipeline valve; the control target value includes: at least one of a desired rotation position, a desired rotation speed, and a maximum current threshold value in the desired rotation;

[0010] The central controller is used to:

[0011] Receiving the control target value of the human-computer interaction module and the feedback data of the pipeline valve collected by the feedback execution module;

[0012] Calculating the control amount of the pipeline valve using a feedback control algorithm according to the control target value and the feedback data;

[0013] The feedback data includes at least one of the actual rotation position, the actual rotation speed and the current in the actual rotation; the control quantity includes at least one of the force position control quantity, the position control quantity, the speed control quantity and the torque control quantity;

[0014] The grassroots controller is used to:

[0015] Applying the control amount to the pipeline valve;

[0016] The feedback execution module is used to:

[0017] The state of the pipeline valve is detected in real time to obtain the feedback data.

[0018] Optionally, the central controller includes: a data receiving module and a multi-mode control module;

[0019] The data receiving module is used for:

[0020] If the current control mode is the force-position mixed control mode, receiving the expected rotation position and the expected rotation speed sent by the human-computer interaction module, and the actual rotation position and the actual rotation speed of the pipeline valve collected by the feedback execution module;

[0021] If the current control mode is the servo position control mode, the expected rotation position, the expected rotation speed and the maximum current threshold in the expected rotation sent by the human-computer interaction module, and the actual rotation position, the actual rotation speed and the actual rotation current of the pipeline valve collected by the feedback execution module are received;

[0022] If the current control mode is the servo speed control mode, receiving the expected rotation speed sent by the human-computer interaction module and the actual rotation speed of the pipeline valve collected by the feedback execution module;

[0023] If the current control mode is the servo torque control mode, the expected rotation position, the expected rotation speed and the maximum current threshold in the expected rotation sent by the human-computer interaction module, and the actual rotation position, the actual rotation speed and the actual rotation current of the pipeline valve collected by the feedback execution module are received;

[0024] The multi-mode control module has a built-in PD controller and a PI controller for:

[0025] If the current control mode is the force-position mixed control mode, the desired rotation position, the desired rotation speed, the actual rotation position and the actual rotation speed are input into the PD controller, and the PD controller applies a force-position control amount to the pipeline valve;

[0026] If the current control mode is the servo position control mode, the expected rotation position, the expected rotation speed, the actual rotation position and the actual rotation speed are input into a PD controller, the output of the PD controller, the maximum current threshold in the expected rotation and the current in the actual rotation are input into the PI controller, and the PI controller applies a position control amount to the pipeline valve through a first PI control algorithm;

[0027] If the current control mode is the servo speed control mode, the desired rotation speed and the actual rotation speed are input into the PD controller, and the PD controller applies a speed control amount to the pipeline valve;

[0028] If the current control mode is the servo torque control mode, the expected rotation position, the expected rotation speed, the actual rotation position and the actual rotation speed are input into the PD controller, the output of the PD controller, the maximum current threshold in the expected rotation and the current in the actual rotation are input into the PI controller, and the PI controller applies the torque control amount to the pipeline valve through the second PI control algorithm.

[0029] Optionally, the closed-loop feedback-controlled numerical control valve control system further includes: an external data measuring device;

[0030] The external data measuring device is connected to the central controller and the grassroots controller respectively;

[0031] The external data measuring device is used to obtain environmental data of the environment in which the pipeline valve is located, and transmit the environmental data to the human-computer interaction module through the central controller;

[0032] The environmental data include: temperature, humidity, pressure and vacuum degree;

[0033] The human-computer interaction module is used to display the environmental data; the control target value of the pipeline valve is determined according to the environmental data.

[0034] Optionally, the human-computer interaction module is further used to:

[0035] Enter the set maximum torque value, set maximum current and set rotation speed of the pipeline valve;

[0036] The central controller is also used for:

[0037] When the expected rotation position exceeds the set maximum torque value, the expected rotation speed exceeds the set rotation speed value, or the maximum current threshold in the expected rotation exceeds the set maximum current, the pipeline valve is controlled to stop operating.

[0038] Optionally, the closed-loop feedback-controlled CNC valve control system further includes: a limit sensor; the limit sensor is arranged at the rotation limit position of the pipeline valve.

[0039] Optionally, the closed-loop feedback-controlled numerical control valve control system further includes: a servo controller and a servo motor;

[0040] The base controller is connected to the servo controller; the servo controller is connected to the pipeline valve through the servo motor; the feedback execution module is connected to the pipeline valve through the servo motor.

[0041] Optionally, the central controller is connected to the human-computer interaction module via a network bus.

[0042] Optionally, the grassroots controller is connected to the servo controller via a CAN bus.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] An embodiment of the present invention proposes a closed-loop feedback-controlled CNC valve control system, which includes: a central controller, a grassroots controller, a human-computer interaction module and a feedback execution module; the central controller is connected to the grassroots controller and the human-computer interaction module respectively; the feedback execution module is connected to the grassroots controller and the central controller respectively, and the central controller obtains at least one of a force control quantity, a position control quantity, a speed control quantity and a torque control quantity according to a control target value and feedback data of the pipeline valve collected by the feedback execution module, thereby achieving precise control of the pipeline valve, thereby achieving precise control of application scenarios with high requirements for flow or rate in the pipeline system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 A structural diagram of a digital control valve control system with closed-loop feedback control provided by an embodiment of the present invention;

[0047] Figure 2A schematic diagram of a closed-loop feedback-controlled numerical control valve control system provided by an embodiment of the present invention;

[0048] Figure 3 A structural diagram of an actuator provided by an embodiment of the present invention;

[0049] Figure 4 A control block diagram of a force-position mixed control mode provided by an embodiment of the present invention;

[0050] Figure 5 A control block diagram of a servo position control mode provided by an embodiment of the present invention;

[0051] Figure 6 A structural diagram of a piping system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0053] The present invention aims to control the flow rate, flow velocity, pressure and other aspects of gas and liquid in a pipeline system with high precision.

[0054] Aiming at the valve control problem in the pipeline system, a CNC valve control system with multiple modes of closed-loop feedback control is proposed. The advantage of the present invention is that the valve closing torque, opening position and other rotation quantities are set by the process system preset and external data, so as to realize the regulation of the pressure, rate, flow and other aspects of the pipeline system and realize the automatic linkage control of multiple valves. The CNC valve control component obtained by the present invention has the characteristics of small size, automatic control of valve opening and closing, controllable and adjustable modes of valve rotation torque, position and other aspects, controllable and adjustable flow and flow rate in the pipeline, and high control accuracy using servo control as the actuator. It is particularly suitable for high-precision control and regulation of valves such as flow, flow rate and pressure of gas and liquid in pipeline systems.

[0055] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] Figure 1 This is a structural diagram of a closed-loop feedback-controlled numerical control valve control system provided by an embodiment of the present invention. Figure 1 The system includes: a central controller, a grassroots controller, a human-computer interaction module and a feedback execution module.

[0057] The central controller is connected to the grassroots controller and the human-computer interaction module respectively; the feedback execution module is connected to the grassroots controller and the central controller respectively.

[0058] The human-computer interaction module is used to input a control target value of the pipeline valve; the control target value includes at least one of an expected rotation position, an expected rotation speed, and a maximum current threshold value in the expected rotation.

[0059] The central controller, as the main controller of the valve control system, is mainly used for feedback data processing, and calculates the control quantity and sends it to the grassroots controller. Specifically, the central controller is used to: receive the control target value of the human-computer interaction module and the feedback data of the pipeline valve collected by the feedback execution module; and calculate the control quantity of the pipeline valve using the feedback control algorithm according to the control target value and the feedback data. The feedback control algorithm can be a PI / PD control algorithm.

[0060] The feedback data includes at least one of the actual rotation position, the actual rotation speed and the current in the actual rotation; the control quantity includes at least one of the force control quantity, the position control quantity, the speed control quantity and the torque control quantity. The human-machine interface (operation interface) on the human-machine interaction module can display the system control state, control quantity, initial value input (target value), etc.

[0061] The grassroots controller uses the control amount of the central controller as input and accurately controls the pipeline valve as an actuator based on the control amount. Therefore, the grassroots controller is used to: apply the control amount to the pipeline valve.

[0062] The feedback execution module is used to detect the state of the pipeline valve in real time to obtain the feedback data. The feedback execution module includes an actuator and a feedback part; the pipeline valve can be used as an actuator; the feedback part can be a feedback sensor installed at the end of the pipeline valve to detect the opening accuracy of the management valve and obtain feedback data.

[0063] The central controller has control modes such as automatic execution and manual execution. Under the automatic execution program, the central controller, including force-position mixed control mode, servo position control mode, servo speed control mode and servo torque (current) control mode, selects the appropriate control mode according to the needs to realize pipeline valve control. The control program can also realize functions such as pause, absolute coordinate and incremental coordinate control of valve position, etc.

[0064] The human-machine interaction module is connected to the central controller via a network bus, and can transmit the current data of the system to the human-machine interface for display, and can select automatic and manual modes on the human-machine interface.

[0065] In one example, in automatic control mode, under the feedback control algorithm of the central controller, the control quantity currently output by the central controller is calculated based on the error between the feedback data (actual value) of the feedback part and the control target value of the pipeline valve of the human-computer interaction module. After receiving the control quantity of the central controller, the grassroots controller automatically realizes the independent or linkage function of multiple valves.

[0066] In manual control mode, the operator inputs the rotation position or torque of each valve in the system through the human-machine interface, and manually controls the opening and closing of the valve.

[0067] Specifically, the central controller includes: a data receiving module and a multi-mode control module.

[0068] The data receiving module is mainly used to read feedback data and use the feedback data as the input of the multi-mode control module. The data receiving module also has a communication interface with the human-computer interaction module. The central controller interacts with the human-computer interaction module through the communication port and can also establish a communication connection with the external network.

[0069] Specifically, the data receiving module is used to:

[0070] If the current control mode is the force-position mixed control mode, the expected rotation position and the expected rotation speed sent by the human-computer interaction module, and the actual rotation position and the actual rotation speed of the pipeline valve collected by the feedback execution module are received.

[0071] If the current control mode is the servo position control mode, the expected rotation position, expected rotation speed and maximum current threshold in the expected rotation sent by the human-computer interaction module, as well as the actual rotation position, actual rotation speed and actual current in the rotation of the pipeline valve collected by the feedback execution module are received.

[0072] If the current control mode is the servo speed control mode, the desired rotation speed sent by the human-computer interaction module and the actual rotation speed of the pipeline valve collected by the feedback execution module are received.

[0073] If the current control mode is the servo torque (current) control mode, the expected rotation position, expected rotation speed and maximum current threshold in the expected rotation sent by the human-computer interaction module, as well as the actual rotation position, actual rotation speed and actual current in the rotation of the pipeline valve collected by the feedback execution module are received.

[0074] Wherein, the multi-mode control module has a built-in PD controller and a PI controller. Specifically, the multi-mode control module is used to:

[0075] 1) If the current control mode is the force-position mixed control mode, the desired rotation position, the desired rotation speed, the actual rotation position and the actual rotation speed are input into the PD controller, and the PD controller applies a force-position control amount to the pipeline valve.

[0076] 2) If the current control mode is the servo position control mode, the expected rotation position, the expected rotation speed, the actual rotation position and the actual rotation speed are input into the PD controller, and the output of the PD controller, the maximum current threshold in the expected rotation and the current in the actual rotation are input into the PI controller, and the PI controller applies the position control quantity to the pipeline valve through the first PI control algorithm.

[0077] 3) If the current control mode is the servo speed control mode, the desired rotation speed and the actual rotation speed are input into the PD controller, and the PD controller applies a speed control amount to the pipeline valve.

[0078] 4) If the current control mode is the servo torque control mode, the expected rotation position, the expected rotation speed, the actual rotation position and the actual rotation speed are input into the PD controller, the output of the PD controller, the maximum current threshold in the expected rotation and the current in the actual rotation are input into the PI controller, and the PI controller applies the torque control amount to the pipeline valve through the second PI control algorithm.

[0079] In another example, the closed-loop feedback controlled CNC valve control system further includes: an external data measuring device.

[0080] The external data measuring device is connected to the central controller and the grassroots controller respectively; the external data measuring device is used to obtain the environmental data of the environment in which the pipeline valve is located, and transmit the environmental data to the human-computer interaction module through the central controller; wherein the environmental data includes: temperature and humidity, pressure and vacuum degree.

[0081] The control quantity output by the central controller is under the feedback control algorithm, and each pipeline valve needs to automatically adjust the valve "opening and closing amount" or rotation position in real time according to the initial value (or target value) set by the pipeline process, external data (pressure, vacuum, etc.). Specifically, the central controller self-adjusts the valve rotation opening and position in real time according to the initial value set by the pipeline system process and external data, and realizes automatic control of the pressure rate or flow of the pipeline system based on the matching relationship between the two.

[0082] The grassroots controller takes the control quantity of the central controller as input, and accurately controls the actuator based on the control quantity (for example, based on the control quantity of the central controller, the grassroots controller acts on the servo controller to automatically control the opening and closing size of the pipeline valve, so that the pipeline system can meet the pressure rate or flow required by the process). The grassroots controller plays a "connecting" role between the actuator and the central controller, and includes the functions of receiving, decoding, and sending control data; at the same time, it can decode the "I / O" signal instructions of the central controller, perform switch control on the system peripherals, realize start and stop control of temperature, humidity, pressure, vacuum, etc., and feedback the current state quantity (current environmental data) to the central controller.

[0083] The human-computer interaction module is used to display the environmental data; the control target value of the pipeline valve is determined according to the environmental data.

[0084] In another example, see Figure 2 The closed-loop feedback-controlled CNC valve control system further includes: a servo controller and a servo motor. Figure 2 The structures in the dashed box are mechanically connected.

[0085] The base controller is connected to the servo controller; the servo controller is connected to the pipeline valve through the servo motor; the feedback execution module is connected to the pipeline valve through the servo motor. In this example, the servo controller, the servo motor and the pipeline valve constitute an actuator. Figure 3 As shown, the servo motor 1 is mechanically connected to the main body of the pipeline valve 2, the servo controller is connected to the servo motor through a cable, and the feedback sensor is installed at the end of the servo motor 1.

[0086] The actuator can also be composed of multiple groups of servo controllers, multiple groups of servo motors and multiple groups of pipeline valves; the number of axes of the actuator can be increased in series / parallel according to the requirements of the pipeline system, and the servo controller and the grassroots controller are connected based on the CAN bus to transmit the control data to the multi-axis servo controller (composed of multiple servo controllers), thereby directly controlling the rotation of the servo motor in the actuator component.

[0087] The central controller is connected to the human-computer interaction module via a network bus.

[0088] The base controller is connected to the servo controller via the CAN bus. The base controller is the "lower level" controller of the central controller, which receives the control quantity of the central controller, connects to the actuator via the CAN bus, controls the torque / position / speed of the pipeline valve, and transmits feedback data (real-time valve rotation data) to the central controller in real time via the feedback sensor.

[0089] The feedback part in the feedback execution module is mechanically connected and installed with the actuator to directly detect the valve rotation position angle, realize the valve "opening" detection, and then accurately adjust the system flow rate.

[0090] In another example, the human-computer interaction module can set initial values ​​such as overload protection, limit protection, current (torque) regulation, valve rotation speed, etc., or set target values ​​for the valve system, and send them to the central controller.

[0091] Specifically, the human-machine interaction module is also used to: input a set maximum torque value, a set maximum current and a set rotation speed value of the pipeline valve.

[0092] The central controller is also used to control the pipeline valve to stop operating when the expected rotation position exceeds the set maximum torque value, the expected rotation speed exceeds the set rotation speed, or the maximum current threshold in the expected rotation exceeds the set maximum current.

[0093] Wherein, the closed-loop feedback-controlled numerical control valve control system further includes: a limit sensor; the limit sensor is arranged at the rotation limit position of the pipeline valve.

[0094] In this example, the central controller has protection functions such as overload protection, limit protection, current (torque) regulation, and valve rotation speed setting.

[0095] In the above embodiments, according to different requirements such as pipeline systems and processes, the combination programming operation of any valves can be realized, and the combination of each valve can be flexible and variable; the control system can accurately realize the torque control when the valve is closed / opened through the current mode; the control system can accurately realize the position control when the valve is closed / opened through the position mode.

[0096] The closed-loop feedback-controlled numerical control valve control system of this embodiment supports multi-valve linkage control as a whole system, and adjusts the valve closing torque, opening position and other rotation quantities based on the process system preset and external data, so as to realize the regulation of the pressure, rate, flow and other aspects of the pipeline system and realize the automatic linkage control of multiple valves. The numerical control valve control component obtained in this embodiment has the characteristics of small size, automatic control of valve opening and closing, controllable and adjustable modes of valve rotation torque, position and other aspects, controllable and adjustable flow and flow velocity in the pipeline, and high control precision using servo control as the actuator, and is particularly suitable for high-precision automatic control and regulation of valves such as flow, flow velocity and pressure of gas and liquid in pipeline systems.

[0097] Several specific embodiments are given below to further illustrate the closed-loop feedback control numerical control valve control system. Specific embodiment 1:

[0099] In the CNC valve control system of multi-mode closed-loop feedback control of this specific example, the central controller is the main control part of the CNC valve control system, which is mainly composed of a data receiving module and a multi-mode control module; the multi-mode control module mainly provides a precise control algorithm for the valve, and the data receiving module receives the feedback of the system and decodes it as the input of the control algorithm. The PI / PD control algorithm of the multi-mode control module uses the feedback data collected by the feedback sensor as input to compare with the valve control target value, and the control amount obtained after the algorithm calculation is sent to the grassroots controller via the CAN bus; the data receiving module receives and reads the feedback data and uses the feedback data as the input of the multi-mode control module. At the same time, it has a communication interface with the human-machine interface. The central controller interacts with the human-machine interface through the communication port and can also establish a communication connection with the external network.

[0100] In the CNC valve control system, the human-machine interface is used to display the control quantity and status data information of the control system in real time. It is connected to the central controller. The central controller transmits the data to the human-machine interface for display, and the operator outputs the initial value or control value on the interface. In this embodiment, the human-machine interface is a touch screen display that can be operated and displayed by touch and is connected to the central controller based on a network bus protocol.

[0101] The basic controller is a sub-controller of the CNC valve control system, "connected in series" between the actuator and the central controller, and includes functions such as control data reception, decoding, and transmission. Based on the CAN bus, the servo controller is connected, and the valve torque / position / speed, etc. are directly controlled according to the control quantity obtained by decoding, and the real-time valve rotation data is transmitted back to the central controller through the feedback part. The basic controller can directly act on each servo controller to control the valve to realize the independent or linkage function of multiple valves; according to the control initial value set by the pipeline system process (human-machine interface setting) and external data (pressure, vacuum, etc.), the valve rotation "opening and closing amount" and position are adjusted.

[0102] The feedback part is mechanically connected to the actuator part, and the feedback sensor is installed at the rear end of the motor. The motor and the valve are connected through a coupling. Therefore, the sensor can directly detect the valve rotation position angle and rotation speed, realize the valve "opening and closing amount" detection, and then accurately adjust the system flow rate.

[0103] Based on the above system control relationship, this specific embodiment describes the force-position mixed control mode, the servo position control mode, and the servo speed control mode in the numerical control valve control system.

[0104] (1) In the force-position mixed control mode implementation method, the human-machine interface first selects the force-position mixed control mode. At this time, the control algorithm called in the control module of the central controller is the PD control algorithm. Figure 4 As shown. Figure 4As shown, in the implementation mode of force-position mixed control, the input is the target value P (desired rotation position pos_desired, desired rotation speed spd__desired) of the human-machine interaction module, and the actual value P0 (actual rotation position pos_current, actual rotation speed spd_current) of the feedback part, and the force-position control quantity motor_current1 is obtained through the PD controller, and finally output to the servo motor, as shown in the following formula:

[0105] motor_current1=

[0106] KP*(pos_desired-pos_current)+

[0107] KD*(spd_desired-spd_current)+Torque / K T

[0108] Where KP is the feedback compensation gain; KD is the damping coefficient. The appropriate values ​​of KP and KD can be determined based on the system debugging process; K T is the motor torque constant; Torque is the motor torque.

[0109] (2) Figure 5 As shown, in the servo position control mode implementation, the human-machine interface first selects the servo position control mode, and the control algorithm called in the control module of the central controller is PI / PD dual closed-loop control, see Figure 5 In this mode, the main input is the actual rotation position and actual rotation speed of the feedback part; the outer loop is the position loop control, which is actually a PD controller; the inner loop is the current loop, which is mainly a PI controller. The input of the PI controller is the output of the PD controller and the current in the actual rotation. The parameters in the PD controller and the PI controller cannot be changed by the user. In this servo position control mode, in the human-machine interface, it requires three input parameters, which are the desired rotation position pos_desired, the desired rotation speed spd__desired, and the maximum current threshold I in the desired rotation. max , that is, the motor controls the valve to move from the current position P0 to the desired rotation position pos_desired; during the process from P0 to pos_desired, the maximum current of the motor is I max , generating maximum torque = I max *Motor torque constant K TIf the load encountered exceeds the torque, the motor will be stalled. In the servo position control mode, the position control quantity motor_current2 is obtained through the PD controller and the PI controller, and finally output to the servo motor. The PI controller uses the first PI control algorithm based on the output quantity motor_current of the PD controller to obtain the position control quantity motor_current2, and its formula is expressed as:

[0110]

[0111] Among them, motor_current represents the output of the PD controller, that is, the current value I c ; motor_current2(t+1) represents the position control value at time t+1; motor_current2(t) represents the position control value at time t, which is essentially the actual rotating current I at time t m , I m ≤I max ; KI is the integral time constant. The calculation formula of motor_current is:

[0112]

[0113] (3) In the servo speed control mode implementation, the human-machine interface selects the servo speed control mode, and the control algorithm called in the control module of the central controller is the PD controller. In this implementation, the input is the actual rotation speed spd_current of the feedback part, and the desired rotation speed spd__desired is input in the human-machine interface, and the speed control quantity motor_current3 is obtained through PI control, and finally the current is output to the servo motor. This mode control method is consistent with the force-position mixed control mode, and its formula is expressed as:

[0114]

[0115] (4) In the servo torque control mode implementation, the human-machine interface selects the servo torque control mode, and the control algorithm called in the control module of the central controller is the PI controller and the PD controller. In this implementation, the PD controller outputs the control quantity motor_current, the input of the PI controller is motor_current, the current in the actual rotation of the feedback part, and the maximum current threshold I in the desired rotation input by the human-machine interface max, and the torque control quantity motor_current4 is obtained through PI control, and finally output to the servo motor. The PI controller uses the second PI control algorithm to obtain the position control quantity motor_current4 based on the output quantity motor_current of the PD controller, and its formula is expressed as:

[0116]

[0117] Among them, motor_current represents the output of the PD controller. The specific calculation formula is the same as that of the servo position control mode, so it is not repeated here. motor_current4(t+1) represents the torque control value at time t+1; motor_current4(t) represents the torque control value at time t, which is essentially the actual rotation current I at time t. m , I m ≤I max .

[0118] It should be noted that all control quantities (force control quantity, position control quantity, speed control quantity, torque control quantity) in the above-mentioned embodiments are current. This embodiment obtains the most suitable current control quantity in each state through various controllers, and then controls the motor through the motor driver to obtain the appropriate torque (servo torque control mode) or position (servo position control mode). Therefore, all mode control quantities are essentially current to control the motor, but the "target quantity" that needs to be precisely controlled in different modes is different. That is, in the servo torque control mode, the torque is used as the judgment condition; in the servo position control mode, the position is used as the judgment condition.

[0119] The above-mentioned several implementation methods are implementation cases in the automatic mode of the CNC valve control system. In this implementation case, the automatic mode is selected on the human-machine interface, or the initial state of the operation process of the CNC valve control system is the automatic mode. It obtains the control quantity according to different implementation methods of the central controller, sends it to the grassroots controller, and after analysis, it is specifically sent to a single or multiple valves in the actuator part to control the system flow or rate. In the automatic mode, each valve needs to automatically adjust the valve "opening and closing amount" or rotation position in real time according to the initial value (or target value) set by the pipeline process, external data (pressure, vacuum, etc.), etc. The central controller automatically controls the opening and closing size of the valve according to the set rate or flow, so that the pipeline system can complete the pressure, rate or flow required by the process. Specific embodiment 2:

[0121] As another specific implementation case of the present invention, this implementation case discloses a manual mode of a numerical control valve control system. In manual mode, any valve in the pipeline system can be opened and closed through the human-machine interface, that is, any valve in the switch system can be "clicked" through the human-machine interface of the numerical control valve control system; at the same time, the expected value of the valve "opening and closing" can be set based on the human-machine interface, and the valve rotation angle can be directly controlled through the central controller, grassroots controller, etc., so as to control the flow of the pipeline system. In this implementation case, in manual mode, the rate or flow of the gas or liquid flowing through the valve can be set by setting the expected flow parameters through the human-machine interface and combining external data (pressure, vacuum, etc.). The central controller controls the valve position opening and closing amount according to the set rate or flow to meet the process requirements. Specific embodiment 3:

[0123] As another specific implementation case of the present invention, this implementation case discloses protection functions such as overload protection, limit protection, current (torque) regulation, and valve rotation speed setting of a numerical control valve control system. In the implementation case, the system overload protection mainly sets the maximum torque value of the valve opening and closing on the human-machine interface. When the motor operates this value with the maximum torque, the motor stops moving and the system is in an overload protection state. In this way, the motor is protected and the system life is extended. The limit protection is to set a limit sensor at the rotation limit position of the motor-driven valve rotation process to ensure that the valve rotation does not exceed the limit and protect the overall valve control system. Current (torque) regulation, valve rotation speed setting, etc. are all to set the maximum current and rotation speed on the human-machine interface. When the expected value set exceeds the setting, the system automatically determines that there is an error and stops running to protect the overall valve numerical control system. In this implementation case, it is also stipulated that when the system encounters "out of control, valve rotation exceeds the limit or other emergency conditions", the operator can use the emergency stop button to realize the emergency stop of the entire system. Specific embodiment 4:

[0125] As another specific implementation case of the present invention, this implementation case discloses Figure 6 The gas mixing system pipeline shown can be precisely controlled based on the numerical control valve system of this embodiment. Figure 6 Where MFC is a mass flow controller, and SV is a structure consisting of a pipeline valve and a servo motor in the actuator part. Figure 6In the implementation case shown, 3 gas inputs and 4 gas outputs are arranged. In actual cases, the CNC valve system based on this embodiment can be expanded to meet the multi-channel (not less than 16 channels) gas input / output functions. In the implementation case, the system flow input / output is controlled based on the CNC valve control system, and the current pipeline flow is fed back to the central controller based on the mass flow controller, and then the precise control of the gas flow of each channel is further realized through the grassroots controller; the precise "opening and closing" and rotation torque of the system valve can also be realized through the feedback part. At the same time, in the implementation case, the precise proportion of the gas inside the mixing tank is mixed through the precise control of the flow rate to obtain the target gas with a precise proportion of composition.

[0126] The numerical control valve control system of the present invention realizes precise control for application scenarios with high requirements for flow or rate in pipeline systems, and the torque and position are controllable and adjustable. The control system can be adaptively set and adjusted through external input, and can output signals to control external devices. It has a friendly human-machine interface and a simple operation interface. The present invention solves the problem of high-precision control and adjustment of flow, flow rate, pressure, etc. of pipeline systems based on multi-mode valve control, ensures that the valve torque and position are controllable and adjustable, improves the control accuracy of the pipeline system, and increases the control mode.

[0127] The closed-loop feedback-controlled numerical control valve control system of the present invention has the following advantages:

[0128] 1. The present invention forms a control operation closed loop through a human-machine interface, a central controller, a grassroots controller, an actuator, and a feedback part, which can realize precise control of the flow rate and rate of the gas or liquid flowing in the valve, and realize precise adjustment of the opening and closing state of the valve, thereby accurately controlling the pipeline system where the valve is located.

[0129] 2. The present invention has multiple modes, including force-position mixed control mode, servo position mode, and current (torque) control mode. You can select the appropriate control mode according to your needs to achieve valve control. At the same time, the control system also has automatic execution mode and manual execution mode to ensure that in the "error" state of the automatic mode, valve control and system flow control can also be completed in manual mode.

[0130] 3. The present invention can realize the start and stop control of external temperature, humidity, pressure, vacuum and other state quantities, and output its state feedback to the central controller, which then acts on the actuator and realizes precise control of the valve based on the above state quantities.

[0131] 4. The valve of the actuator of the present invention is controlled by a full servo motor, with high rotation accuracy and motion accuracy of up to ±5μm, and the valve "opening and closing amount" or rotation torque and position are controllable and adjustable.

[0132] 5. The central controller of the present invention can support the multi-valve linkage function, that is, it can control the opening and closing of multiple valves at the same time; and the central controller and the grassroots controller can support the multi-axis expansion of the actuator, that is, support series / parallel increase of the number of axes of the actuator, thereby realizing the expansion of the pipeline system function.

[0133] 6. The control system of the present invention can realize the combined programming operation of any valves according to different requirements such as pipeline systems and processes, and the combination of each valve is flexible and variable; at the same time, under the control algorithm, the valve "opening and closing amount" or rotation position of each valve can be automatically adjusted in real time based on external data (pressure, vacuum degree, etc.).

[0134] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0135] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A closed-loop feedback controlled numerical control valve control system, characterized in that: include: Central controller, grassroots controller, human-computer interaction module and feedback execution module; The central controller is connected to the grassroots controller and the human-computer interaction module respectively; the feedback execution module is connected to the grassroots controller and the central controller respectively; The human-machine interaction module is connected to the central controller via a network bus, transmits the current data of the system to the human-machine interface for display, and selects automatic and manual modes on the human-machine interface for: A control target value of the input pipeline valve; the control target value includes: at least one of a desired rotation position, a desired rotation speed, and a maximum current threshold value in the desired rotation; In the automatic control mode, under the feedback control algorithm of the central controller, the control amount currently output by the central controller is calculated according to the error between the feedback data of the feedback part and the control target value of the pipeline valve of the human-machine interaction module. After receiving the control amount of the central controller, the grassroots controller automatically realizes the independent or linkage function of multiple valves; In manual control mode, the operator inputs the rotation position or torque of each valve in the system through the human-machine interface, and manually jogs the valve to control the opening and closing of the valve; The central controller includes: a data receiving module and a multi-mode control module, and has automatic execution and manual execution control modes. Under the automatic execution program, the central controller includes a force-position mixed control mode, a servo position control mode, a servo speed control mode and a servo torque control mode. The appropriate control mode is selected according to the needs to realize pipeline valve control. The control program realizes the functions of pausing and controlling the valve position using absolute coordinates and incremental coordinates, and is used for: Receiving the control target value of the human-computer interaction module and the feedback data of the pipeline valve collected by the feedback execution module; Calculating the control amount of the pipeline valve using a feedback control algorithm according to the control target value and the feedback data; The feedback data includes at least one of the actual rotation position, the actual rotation speed and the current in the actual rotation; the control quantity includes at least one of the force control quantity, the position control quantity, the speed control quantity and the torque control quantity; the human-machine interface display system control state, control quantity and initial value input on the human-machine interaction module specifically include: The data receiving module is used for: If the current control mode is the force-position mixed control mode, receiving the expected rotation position and the expected rotation speed sent by the human-computer interaction module, and the actual rotation position and the actual rotation speed of the pipeline valve collected by the feedback execution module, specifically includes: In the force-position mixed control mode implementation, the human-machine interface first selects the force-position mixed control mode. At this time, the control algorithm called in the control module of the central controller is the PD control algorithm. In the force-position mixed control mode implementation, the input is the target value P of the human-machine interaction module and the actual value P0 of the feedback part, and the force-position control quantity motor_current1 is obtained through the PD controller, and finally output to the servo motor, as shown in the following formula: motor_current1= KP*(pos_desired-pos_current)+ KD*(spd_desired-spd_current)+Torque / KT Among them, the target value P includes the desired rotation position pos_desired, the desired rotation speed and spd__desired, the actual value P0 includes the actual rotation position pos_current and the actual rotation speed spd_current, KP is the feedback compensation gain; KD is the damping coefficient, and the appropriate values ​​of KP and KD are determined based on the system debugging process; KT is the motor torque constant; Torque is the motor torque; If the current control mode is the servo position control mode, the expected rotation position, the expected rotation speed and the maximum current threshold in the expected rotation sent by the human-computer interaction module, and the actual rotation position, the actual rotation speed and the actual rotation current of the pipeline valve collected by the feedback execution module are received; If the current control mode is the servo speed control mode, receiving the expected rotation speed sent by the human-computer interaction module and the actual rotation speed of the pipeline valve collected by the feedback execution module; If the current control mode is the servo torque control mode, the expected rotation position, the expected rotation speed and the maximum current threshold in the expected rotation sent by the human-computer interaction module, and the actual rotation position, the actual rotation speed and the actual rotation current of the pipeline valve collected by the feedback execution module are received; The multi-mode control module has a built-in PD controller and a PI controller for: If the current control mode is the force-position mixed control mode, the desired rotation position, the desired rotation speed, the actual rotation position and the actual rotation speed are input into the PD controller, and the PD controller applies a force-position control amount to the pipeline valve; If the current control mode is the servo position control mode, the expected rotation position, the expected rotation speed, the actual rotation position and the actual rotation speed are input into a PD controller, the output of the PD controller, the maximum current threshold in the expected rotation and the current in the actual rotation are input into the PI controller, and the PI controller applies a position control amount to the pipeline valve through a first PI control algorithm; If the current control mode is the servo speed control mode, the desired rotation speed and the actual rotation speed are input into the PD controller, and the PD controller applies a speed control amount to the pipeline valve; If the current control mode is the servo torque control mode, the expected rotation position, the expected rotation speed, the actual rotation position and the actual rotation speed are input into a PD controller, the output of the PD controller, the maximum current threshold in the expected rotation and the current in the actual rotation are input into the PI controller, and the PI controller applies a torque control amount to the pipeline valve through a second PI control algorithm; The grassroots controller is used to: Applying the control amount to the pipeline valve; The feedback execution module is used to: Real-time detection of the state of the pipeline valve to obtain the feedback data; The feedback execution module includes an actuator and a feedback part. The pipeline valve serves as the actuator, and the feedback part is a feedback sensor installed at the end of the pipeline valve to check the opening accuracy of the management valve and obtain feedback data.

2. A closed-loop feedback controlled numerical control valve control system according to claim 1, characterized in that: Also includes: External data measurement device; The external data measuring device is connected to the central controller and the grassroots controller respectively; The external data measuring device is used to obtain environmental data of the environment in which the pipeline valve is located, and transmit the environmental data to the human-computer interaction module through the central controller; The environmental data include: temperature, humidity, pressure and vacuum degree; The human-computer interaction module is used to display the environmental data; the control target value of the pipeline valve is determined according to the environmental data.

3. A closed-loop feedback controlled numerical control valve control system according to claim 1, characterized in that: The human-computer interaction module is also used for: Enter the set maximum torque value, set maximum current and set rotation speed of the pipeline valve; The central controller is also used for: When the expected rotation position exceeds the set maximum torque value, the expected rotation speed exceeds the set rotation speed value, or the maximum current threshold in the expected rotation exceeds the set maximum current, the pipeline valve is controlled to stop operating.

4. A closed-loop feedback controlled numerical control valve control system according to claim 1, characterized in that: Also includes: Limit sensor; the limit sensor is arranged at the rotation limit position of the pipeline valve.

5. The closed-loop feedback controlled numerical control valve control system according to claim 1, characterized in that: Also includes: Servo controller and servo motor; The base controller is connected to the servo controller; the servo controller is connected to the pipeline valve through the servo motor; the feedback execution module is connected to the pipeline valve through the servo motor.

6. A closed-loop feedback controlled numerical control valve control system according to claim 1, characterized in that: The central controller is connected to the human-computer interaction module via a network bus.

7. A closed-loop feedback controlled numerical control valve control system according to claim 5, characterized in that: The base controller is connected to the servo controller via a CAN bus.

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