An electric valve positioning compensation control system and control method

Abstract

An electric valve positioning compensation control system and a control method. The control system includes a single-chip microcomputer. The signal input end of the single-chip microcomputer is connected to the signal output end of the upper controller. The signal output end of the single-chip microcomputer is connected to the signal input end of the valve driving circuit. The signal output end of the single-chip microcomputer is connected to the signal input end of the electric valve actuator. A single-chip microcomputer is added between the upper controller and the valve driving circuit to detect the time length of the valve opening or closing control signal sent by the upper controller, and can calculate the time length of the valve opening or closing pulse required for the electric valve actuator to reach the expected rotation angle according to the set control algorithm, and send it to the valve driving circuit, so that the electric valve actuator reaches the rotation angle increment expected by the upper controller, solves the problem that the valve rotation angle and the valve opening or closing pulse control time are not linearly proportional, improves the positioning accuracy of the valve actuator, and realizes more accurate adjustment of process parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of positioning compensation control, and particularly relates to an electric valve positioning compensation control system and a control method. Background Art

[0002] According to the structural form of the actuator, electric valves are mainly divided into two categories: absolute type and incremental type. The absolute type electric valve receives the absolute position signal of the valve opening degree sent by the upper control system to realize valve position adjustment; the incremental type electric valve receives the opening or closing valve level signal of the upper control system to realize valve position adjustment. Since the structure of the incremental type electric valve is simpler than that of the absolute type electric valve, and the cost of the upper control system is lower, it has been widely used in occasions where economic benefits are pursued. The incremental type electric valve is usually driven by a single-phase motor or a three-phase motor. The upper control system sends an opening or closing valve level signal, which generates a current for driving the motor to rotate forward or backward through a solid-state relay, so that the valve opening degree increases or decreases, realizing the adjustment of the flowing fluid. When applying the incremental type electric valve, the upper control system expects that the angular increment of the valve is linearly proportional to the time length of the sent opening or closing valve level signal. However, in fact, due to the inertia, slip rate of the valve driving motor and the non-linear factors in the starting and accelerating processes, the angular increment of the valve cannot meet this requirement, resulting in the inconsistency between the actual opening increment of the valve and the expected opening increment, and the actuator cannot reach the expected angular position, making it difficult to realize the precise adjustment of process parameters. Summary of the Invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide an electric valve positioning compensation control system and a control method, which can receive the opening or closing valve control signal of the upper control system, perform compensation in the control system, and send the compensated opening or closing valve control signal to the valve driving device to realize the output angular compensation control of the valve, so that the output angle of the valve actuator is consistent with the angular increment expected by the upper control system, and precise adjustment is realized.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An electric valve positioning compensation control system includes a single-chip microcomputer 2. The signal input end of the single-chip microcomputer 2 is connected to the signal output end of the upper controller 4, the signal output end of the single-chip microcomputer 2 is connected to the signal input end of the valve driving circuit 3, and the signal output end of the single-chip microcomputer 2 is also connected to the signal input end of the electric valve actuator 1.

[0006] The upper controller 4 adopts a DCS system.

[0007] The single-chip microcomputer 2 receives the valve opening control signal CW_IN and the valve closing control signal CCW_IN sent by the DCS system of the upper controller 4 through the valve opening and closing pins. The signal output port of the single-chip microcomputer 2 is connected to the fully open and fully closed limits of the valve driving circuit 3, and issues the valve opening control signal CW_OUT and the valve closing control signal CCW_OUT. The signal output end of the single-chip microcomputer 2 is connected to the electric valve actuator 1 through the valve opening and closing control output ports; the single-chip microcomputer 2 is also provided with an input port for analog signals.

[0008] An electric valve positioning compensation control method specifically includes the following steps:

[0009] Step 1: Let the function expression of the actual output rotation angle increment of the electric valve actuator 1 and the energization development or valve closing time length be θ1 = g(t);

[0010] Step 2: The single-chip microcomputer 2 receives the valve opening or closing pulse control signal sent by the upper controller 4 for a time length of t2;

[0011] Step 3: Calculate the expected rotation angle increment γ1 according to the function relationship γ1 = f(t) between the expected rotation angle increment of the upper controller 4 and the valve opening or closing time length;

[0012] Step 4: Make the actual output rotation angle increment θ1 equal to the expected rotation angle increment γ1, and substitute it into the function expression θ1 = g(t) to calculate the pulse time length t3 of the control signal that needs to be sent to reach the expected rotation angle increment γ1 in reverse;

[0013] Step 5: The single-chip microcomputer 2 sends a pulse control signal with a time length of t3 to the driving element of the electric valve actuator 1, so that the output rotation angle of the electric valve actuator 1 is consistent with the expected rotation angle.

[0014] The described electric valve actuator 1 is an incremental electric actuator and works by receiving the incremental valve opening or closing pulse control signal of the upper controller 4.

[0015] The driving element in the described electric valve actuator 1 includes a solid-state relay.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] Compared with the existing electric valve actuators, a single-chip microcomputer 2 is added between the upper controller 4 and the valve drive circuit 3. The time length of the valve opening or closing control signal sent by the upper controller 4 is detected, and the time length of the valve opening or closing pulse required for the electric valve actuator 1 to reach the expected rotation angle can be calculated according to the set control algorithm, and sent to the valve drive circuit 3, so that the electric valve actuator 1 reaches the expected rotation angle increment of the upper controller 4, solving the problem that in the existing technology, the valve drive circuit is usually directly connected to the valve opening or closing pulse control signal of the upper controller, and the valve rotation angle is not linearly proportional to the valve opening or closing pulse control time, improving the positioning accuracy of the electric valve actuator 1 and realizing more accurate adjustment of process parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the control system of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the control system of the present invention.

[0020] Figure 3 It is a flowchart of the control method of the present invention.

[0021] Among them, 1, electric valve actuator; 2, single-chip microcomputer; 3, valve drive circuit; 4, upper controller. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings.

[0023] An electric valve positioning compensation control system includes a single-chip microcomputer 2. The signal input end of the single-chip microcomputer 2 is connected to the signal output end of the upper controller 4, the signal output end of the single-chip microcomputer 2 is connected to the signal input end of the valve drive circuit 3, and the signal output end of the single-chip microcomputer 2 is also connected to the signal input end of the electric valve actuator 1.

[0024] The upper controller 4 adopts a DCS system.

[0025] The single-chip microcomputer 2 receives the valve opening control signal CW_IN and the valve closing control signal CCW_IN sent by the DCS system of the upper controller 4 through the valve opening and closing pins. The signal output port of the single-chip microcomputer 2 is connected to the fully open and fully closed limits of the valve drive circuit 3, and sends out the valve opening control signal CW_OUT and the valve closing control signal CCW_OUT. The signal output end of the single-chip microcomputer 2 is connected to the electric valve actuator 1 through the valve opening and closing control output ports; the single-chip microcomputer 2 is also provided with an input port for analog signals, and the power supply port of the single-chip microcomputer 2 is connected to a 5V power supply.

[0026] An electric valve positioning compensation control method specifically includes the following steps:

[0027] Step 1: Set the function expression of the actual output rotation angle increment of the electric valve actuator 1 and the energization time length for opening or closing the valve as θ1 = g(t);

[0028] Step 2: The single-chip microcomputer 2 receives the time length t2 of the opening or closing valve pulse control signal sent by the upper controller 4;

[0029] Step 3: Calculate the expected rotation angle increment γ1 according to the function relationship γ1 = f(t) between the expected rotation angle increment of the upper controller 4 and the opening or closing valve time length;

[0030] Step 4: Make the actual output rotation angle increment θ1 equal to the expected rotation angle increment γ1, and substitute it into the function expression θ1 = g(t) to inversely calculate the time length t3 of the control signal pulse that needs to be sent to reach the expected rotation angle increment γ1;

[0031] Step 5: The single-chip microcomputer 2 sends a pulse control signal with a time length of t3 to the driving element of the electric valve actuator 1, so that the output rotation angle of the electric valve actuator 1 is consistent with the expected rotation angle.

[0032] The electric valve actuator 1 is an incremental electric actuator and works by receiving the incremental opening or closing valve pulse control signal of the upper controller 4.

[0033] The driving element in the electric valve actuator 1 includes a solid-state relay.

[0034] Compared with the existing electric valve actuator 1, the present invention adds a single-chip microcomputer 2 between the upper controller 4 and the valve driving circuit 3, which can detect the time length of the opening or closing valve control signal sent by the upper controller, and can calculate the time length of the opening or closing valve pulse that the electric valve actuator 1 needs to send to reach the expected rotation angle according to the set control algorithm, and send it to the valve driving circuit 3, so that the electric valve actuator 1 reaches the expected rotation angle increment of the upper control system, solves the problem that the existing valve driving circuit 3 is usually directly connected to the opening or closing valve pulse control signal of the upper controller, and the valve rotation angle and the opening or closing valve pulse control time are not in a linear proportional relationship, improves the positioning accuracy of the electric valve actuator 1, and realizes more accurate adjustment of process parameters.

Claims

1. Control method of an electric valve positioning compensation control system, characterized in that: The electric valve positioning compensation control system includes a single-chip microcomputer (2), the signal input end of the single-chip microcomputer (2) is connected to the signal output end of the upper controller (4), the signal output end of the single-chip microcomputer (2) is connected to the signal input end of the valve drive circuit (3), and the signal output end of the single-chip microcomputer (2) is also connected to the signal input end of the electric valve actuator (1); The control method specifically includes the following steps: First step: Let the function expression of the actual output rotation angle increment of the electric valve actuator (1) and the energization time length for opening or closing the valve be θ1 = g(t); Second step: The single-chip microcomputer (2) receives the time length of the opening or closing valve pulse control signal sent by the upper controller (4) as t2; Third step: Calculate the expected rotation angle increment γ1 according to the function relationship γ1 = f(t) between the expected rotation angle increment and the opening or closing valve time length of the upper controller (4); Fourth step: Make the actual output rotation angle increment θ1 equal to the expected rotation angle increment γ1, and substitute it into the function expression θ1 = g(t) to calculate the pulse time length t3 of the control signal that needs to be sent to reach the expected rotation angle increment γ1; Fifth step: The single-chip microcomputer (2) sends a pulse control signal with a time length of t3 to the drive element of the electric valve actuator (1), so that the output rotation angle of the electric valve actuator (1) is consistent with the expected rotation angle.

2. The control method of an electric valve positioning compensation control system according to claim 1, characterized in that: The single-chip microcomputer (2) receives the opening valve control signal CW_IN and the closing valve control signal CCW_IN sent by the DCS system of the upper controller (4) through the opening and closing valve pins. The signal output port of the single-chip microcomputer (2) is connected to the fully open and fully closed limits of the valve drive circuit (3), and sends out the opening valve control signal CW_OUT and the closing valve control signal CCW_OUT. The signal output end of the single-chip microcomputer (2) is connected to the electric valve actuator (1) through the opening and closing valve control output ports; the single-chip microcomputer (2) is also provided with an input port for analog signals.

3. The control method of an electric valve positioning compensation control system according to claim 1 or 2, characterized in that: The upper controller (4) adopts a DCS system.

4. The control method of an electric valve positioning compensation control system according to claim 1 or 2, characterized in that: The electric valve actuator (1) is an incremental electric actuator and works by receiving the incremental opening or closing valve pulse control signal of the upper controller (4).

5. The control method of an electric valve positioning compensation control system according to claim 1 or 2, characterized in that: The drive element in the electric valve actuator (1) includes a solid-state relay.

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