Control device, valve device, program, storage medium, and control method

Abstract

[Problem] To develop a technology for shortening the time for initialization processing in comparison to a conventional control device. [Solution] A control device of the present embodiment is configured to perform: initialization processing for setting a current position of a movable part of a flow rate control valve to an origin position, after the movable part is disposed at one end of a movable range and stoppers are pressed against each other; position control processing for acquiring information on a target position using the origin position as a reference, and performing position control so that the movable part moves from the current position to the target position; backup processing for storing the current position and the target position, which is a movement destination of the movable part from the current position, in a nonvolatile storage part; and special position control processing, which is included in the initialization processing, for performing position control so that the movable part moves using, among two storage positions consisting of the current position and the target position stored in the nonvolatile storage part, the storage position on a side far from the origin position as a starting point, and using the origin position or a virtual position farther from the storage position than the origin position as an end point.

Description

Control device, valve device, program, storage medium, and control method

[0001] The present disclosure relates to a control device and control method for a flow control valve, a valve device equipped with such a control device, a program executed by a computer of such a control device, and a storage medium for storing the program.

[0002] A known control device of this type is one that moves the movable part to one end of the movable range to press the stoppers together, and then performs an initialization process to set the current position of the movable part to the origin position. In this process, the control device controls the movable part to move by a target amount of movement that exceeds the entire movable range (hereinafter referred to as "full-range movement control of the movable part") in order to reliably press the stoppers together (see, for example, Patent Document 1).

[0003] JP-A-2-17277 (Page 4, lines 6-11 in the lower left column)

[0004] There is a demand for the development of a technique for shortening the initialization process time for the above-mentioned conventional control device.

[0005] A control device according to one aspect of the present invention is a control device configured to perform the following: an initialization process in which, after the movable part of a flow control valve is positioned at one end of its movable range and the stoppers are pressed together, the current position of the movable part is set to an origin position; a position control process in which information on a target position based on the origin position is acquired and the movable part is controlled to move from the current position to the target position; a backup process in which the current position and the target position to which the movable part will move from the current position are stored in a non-volatile memory; and a special position control process included in the initialization process in which the movable part is controlled to move from the memory position farther from the origin position of two memory positions consisting of the current position and the target position stored in the non-volatile memory, with the memory position farther from the origin position as the starting point and the origin position or a virtual position farther from the memory position than the origin position as the end point.

[0006] A program according to one aspect of the present invention causes a computer of a control device for a flow control valve to function as: an initialization unit configured to set the current position of the movable part to an origin position after the movable part of the flow control valve is positioned at one end of its movable range and the stoppers are pressed together; a position control unit configured to acquire information on a target position based on the origin position and control the position of the movable part so that it moves from the current position to the target position; a backup unit configured to save the current position and the target position to which the movable part is to move from the current position in a non-volatile memory unit; and a special position control unit included in the initialization unit and configured to control the position of the movable part so that the starting point is the memory position farther from the origin position out of two memory positions consisting of the current position and the target position stored in the non-volatile memory unit, and the origin position or a virtual position farther from the memory position than the origin position is the end point.

[0007] A control method according to one aspect of the present invention is a control method that performs the following steps: an initialization process in which a movable part of a flow control valve is positioned at one end of its movable range and stoppers are pressed together, and then the current position of the movable part is set to an origin position; a position control process in which information on a target position based on the origin position is acquired and the movable part is controlled to move from the current position to the target position; a backup process in which the current position and the target position to which the movable part will move from the current position are saved in a non-volatile memory; and a special position control process that is included in the initialization process and controls the position of the movable part so that the movable part moves from the current position to the farther memory position of two memory positions consisting of the current position and the target position stored in the non-volatile memory, with the farther memory position being the starting point and the origin position or a virtual position farther from the memory position than the origin position being the end point.

[0008] 1 is a side cross-sectional view of a flow control valve according to a first embodiment; FIG. 2 is a circuit diagram of a control device; FIG. 3 is a conceptual diagram of an excitation pattern; FIG. 4 is a program flowchart; FIG. 5 is a flowchart of an initial position setting process in the program; FIG. 6 is a flowchart of a position control process in the program;

[0009] 1 to 7, a valve device 10 according to a first embodiment of the present invention will be described. The valve device 10 includes a flow control valve 11 and a control device 30A that controls the flow control valve 11, and is used, for example, as part of an air conditioning system for an automobile.

[0010] The motor 12, which is the drive source of the flow control valve 11, is, for example, a stepping motor, and has a male screw portion 14N and a female screw portion 20N that screw together on the central shaft 14 of its rotor 13 and on a base portion 20 that rotatably supports the central shaft 14. As a result, a valve element 18, which will be described below, moves linearly as the rotor 13 rotates.

[0011] A central hole 14A is formed at one end of the central shaft 14, and the base end of a needle-shaped valve element 18 is fitted therein in a slidable but retained manner. A compression coil spring 18S housed in the central hole 14A biases the valve element 18 in the direction that it protrudes from the central shaft 14.

[0012] The base portion 20 is formed with a first hole 21A extending coaxially with the central shaft 14 and a second hole 21B laterally communicating with the first hole 21A, forming an L-shaped flow path 21 through which a fluid can pass from the first hole 21A and the second hole 21B. The first hole 21A is narrowed at a portion away from the second hole 21B to form a valve hole 22. The valve element 18 moves linearly toward and away from the valve hole 22, changing the opening degree of the valve hole 22 and changing the flow rate of the fluid passing through the flow path 21. When the valve element 18 abuts against a valve seat 23, which is part of the inner surface of the valve hole 22, the valve hole 22 is closed.

[0013] A screw guide 19G, formed by spirally wound wire, is fixed to the end of the central shaft 14 opposite the valve body 18 so as to rotate integrally with the central shaft 14. A stopper 19A, formed by spirally wound wire with a larger diameter and shorter length than the screw guide 19G, is threadedly engaged with the outer surface of the screw guide 19G. A pair of stoppers 19S1 and 19S2 are provided at both ends of the screw guide 19G. The stopper 19A abuts against the pair of stoppers 19S1 and 19S2 to prevent it from detaching from the screw guide 19G. Furthermore, a rotation restriction bar 90A extends parallel to the central shaft 14 from one end of a rotor case 90 that houses the rotor 13 of the motor 12. The rotation restriction bar 90A is disposed to the side of the screw guide 19G, and a portion of the stopper 19A abuts against the rotation restriction bar 90A. The rotation limiting mechanism 19K, which includes the screw guide 19G, the stopper 19A, and the rotation restricting bar 90A, causes the stopper 19A to move linearly along the rotation restricting bar 90A as the rotor 13 rotates. When the rotor 13 rotates in one direction, as shown in Fig. 1, the stopper 19A comes into contact with a stopper 19S1 at one end of the screw guide 19G, positioning the rotor 13 at one end of its rotatable range. When the rotor 13 rotates in the other direction from that end position, the stopper 19A comes into contact with a stopper 19S2 at the other end of the screw guide 19G, positioning the rotor 13 at the other end of its rotatable range. The rotatable range of the rotor 13 is incorporated as a maximum rotatable angle θmax of the rotor 13 into part of the program PG1, which will be described later, and is stored in the mask ROM 36C.

[0014] In this embodiment, the "position" in the "origin position," "current position," "target position," etc. of the rotor 13 described below means the "rotational position" of the rotor 13, and the movement of the rotor 13 means that the rotor 13 rotates.

[0015] In the flow control valve 11 of this embodiment, one end position of the rotatable range of the rotor 13, which is positioned by the abutment of the stoppers 19A, 19S1, is set as an origin position for controlling the rotational position of the rotor 13 (i.e., for controlling the position of the motor 12) by a control device 30A described below. Furthermore, at this end position of the rotor 13, i.e., the origin position, the valve element 18 abuts against the valve seat 23, and the compression coil spring 18S is in a slightly deflected state.

[0016] In this embodiment, when the rotor 13 is located at the home position, the valve element 18 abuts against the valve seat 23 to fully close the valve hole 22. However, when the rotor 13 is located at the home position, the valve element 18 may be slightly spaced from the valve seat 23 to allow a small amount of fluid to pass through the valve hole 22. In this embodiment, the stoppers 19A, 19S1 that position the rotor 13 at the home position are provided inside the motor 12, but they may be provided outside the motor 12. For example, the valve element 18 and the valve seat 23 may serve as stoppers, and the rotor 13 may be positioned at the home position when they abut against each other. In this case, it is preferable that the valve element 18 is fixed to the central shaft 14 so as not to slide.

[0017] 2, the control device 30A includes a drive circuit 33 for driving the motor 12 and a control circuit 36 ​​for controlling the drive circuit 33. To explain the configuration of the drive circuit 33, the configuration of the motor 12 will be explained more specifically. As shown in FIG. 1, the motor 12 is a claw-pole stepping motor having a permanent magnet 13M (see FIG. 1) in the rotor 13 and two-phase coils 91, 92 in the stator 93.

[0018] 2, the drive circuit 33 is connected to the coils 91 and 92 in, for example, a unipolar configuration and has four switches 31A, 31a, 32B, and 32b, with one coil 91 divided into coils A and a, and the other coil 92 divided into coils B and b. The switches 31A, 31a, 32B, and 32b correspond one-to-one to the coils A, a, B, and b, and when any of the switches is turned on, a drive current is passed through the corresponding coil.

[0019] The control circuit 36 ​​includes a CPU 36A, a RAM 36B, a mask ROM 36C, and an EEPROM 36D. The mask ROM 36B stores an excitation pattern P for rotating the rotor 13, an example of which is shown in FIG. 3 . As shown in FIG. 3 , the excitation pattern P is composed of excitation patterns PA, Pa, PB, and Pb for the coils A, a, B, and b, respectively. In FIG. 3 , the horizontal axis represents time and the number of steps. In this example excitation pattern, one electrical rotation of the rotor 13 is divided into four steps ST. Each time step ST is switched in the direction of the time axis in FIG. 3 , the combination of excitation and non-excitation of coils A, a, B, and b is switched, and the rotor 13 is rotated in the valve closing direction by one-quarter of an electrical rotation. Furthermore, by switching step ST in the direction opposite to the direction of the time axis in FIG. 3 , the rotor 13 is rotated in the valve opening direction. The number of steps in the excitation patterns PA, Pa, PB, and Pb can be changed arbitrarily, thereby changing the rotation angle of the rotor 13 arbitrarily.

[0020] 4 to 6 is stored in the mask ROM 36C. That is, the mask ROM 36C serves as a storage medium for storing the program PG1. The program PG1 is executed, for example, when the control device 30A is powered on.

[0021] As shown in FIG. 4, when program PG1 is executed, first, an initial value setting process (S10) is executed, and variables and flags used in the storage area of ​​RAM 36B, θx, θ1, θ2, θ11, θ12, FLG1, and FLG11, are set to "0".

[0022] Next, an initial position setting process (S12) is executed. After the initial position setting process (S12) is executed, as shown in FIG. 5, it is checked whether or not there is an external origin setting command (in this embodiment, the ECU of the automobile) (S20). If there is an external origin setting command (YES in S20), a normal initialization process (S100) consisting of the following steps S27 to S29 is executed. If there is no external origin setting command (NO in S20), a special initialization process (S101) consisting of the following steps S21 to S25, S28, and S29 is executed, or the following origin restoration process (S26) is executed.

[0023] In the normal initialization process (S100), a value obtained by adding a preset additional rotation angle θa to the aforementioned maximum rotatable angle θmax is stored in a variable θx (S27). Hereinafter, the variable θx will be referred to as the target rotation angle θx. Then, a control signal is output to rotate the rotor 13 in the negative direction (i.e., toward the valve closing direction) by the target rotation angle θx (S28). That is, full-range movement control is performed, which is control to move the rotor 13, which is a moving part, throughout its entire movable range. Specifically, the CPU 36A outputs a control signal to the switches 31A, 31a, 32B, and 32b to switch the excitation patterns PA, Pa, PB, and Pb of the coils A, a, B, and b by the number of steps required to rotate the rotor 13 from its current position toward the valve closing direction by the target rotation angle θx.

[0024] In this embodiment, "rotation by θx" simply means "rotation by θx in the valve-opening direction," and "rotation by -θx" means "rotation by θx in the valve-closing direction." Therefore, when θx is a negative value, "rotation by θx" causes the rotor 13 to rotate from its current position to the valve-closing side, and when θx is a positive value, "rotation by θx" causes the rotor 13 to rotate from its current position to the valve-opening side.

[0025] When switches 31A, 31a, 32B, and 32b are turned on and off in response to control signals through the full-range movement control described above, the excitation states of coils A, a, B, and b are switched so that rotor 13 rotates in the valve-closing direction by the target rotation angle θx. However, before the rotation angle of rotor 13 reaches the target rotation angle θx, stopper 19A abuts against stopper 19S1, rendering rotor 13 unable to rotate. Since the excitation states of coils A, a, B, and b continue to switch so as to rotate rotor 13 in the valve-closing direction, motor 12 repeatedly loses and regains synchronization while stopper 19A is pressed against stopper 19S1. When the output of the control signal from CPU 36A is completed, the excitation states of coils A, a, B, and b are maintained at the excitation state of the last step. The current position of rotor 13 at this time is stored as the origin position in variable θ1 (S29). In other words, the initial position, which is the position of the rotor 13 that is first positioned after the control device 30A is powered on, is set as the origin position.

[0026] In detail, the current position of the rotor 13 is stored (saved) in a variable θ1 in a storage area of ​​the RAM 36B as position information indicating that "the number of steps away from the origin position is 0." Then, as will be described later, each time the rotor 13 is driven to rotate, the current position of the rotor 13 is updated and stored as position information indicating "the number of steps away from the origin position." In this way, the origin position is identified from the position information of the current position of the rotor 13 stored in the variable θ1. In other words, the origin position is set by storing the current position of the rotor 13 in the RAM 36B. Hereinafter, the variable name of "θ1" will be referred to as the "current position variable θ1."

[0027] In the special initialization process (S101), the current position of the rotor 13 is also stored in the current position variable θ1, and the origin position is set accordingly. The details of the special initialization process (S101) will be described later.

[0028] As shown in Fig. 4, when the initial position setting process (S12) is completed, the position of the motor 12 is controlled in accordance with command data from the ECU of the vehicle. That is, the process waits until command data is provided from the outside (NO loop in S13), and when command data is provided (YES in S13), the position control process (S14) is executed. Here, the command data is provided as, for example, a target valve opening or a target flow rate of the flow control valve 11. A data table that associates command data with target positions of the rotor 13 is stored in the mask ROM 36C.

[0029] When command data is provided and the position control process (S14) is executed, a target position corresponding to the command data is determined based on the data table (S30), as shown in Fig. 6. Next, the target position is stored in variable θ2 (S31), and FLG1 is set to 1 (S32). Hereinafter, the name of the θ2 variable will be referred to as the "target position variable θ2," and the name of the flag in FLG1 will be referred to as the "status flag FLG1."

[0030] Next, a backup process (S33) is executed, and the position information stored in the current position variable θ1 is saved in EEPROM 36D as the first backup data, the position information stored in the target position variable θ2 is saved in EEPROM 36D as the second backup data, and the discrimination information set in the status flag FLG1 is saved in EEPROM 36D as the third backup data.

[0031] Next, a drive process (S50) is executed to move the rotor 13 to the target position. In the drive process (S50), it is first determined whether the number of steps from the origin position, which is the position information of the current position variable θ1, is the same as the number of steps from the origin position, which is the position information of the target position variable θ2 (S51). If the position information of the current position variable θ1 and the position information of the target position variable θ2 are not the same (NO in S51), it is determined whether the number of steps from the origin position, which is the position information of the current position variable θ1, is smaller than the number of steps from the origin position, which is the position information of the target position variable θ2 (S52). That is, it is determined whether the rotor 13 should be rotated in the valve-opening direction or the valve-closing direction. If the number of steps from the origin position, which is the position information of the current position variable θ1, is greater than the number of steps from the origin position, which is the position information of the target position variable θ2 (NO in S52), a control signal to rotate the rotor 13 one step from the current position in the valve-closing direction is output from the CPU 36A (S53). Furthermore, if the number of steps from the origin position, which is the position information of the current position variable θ1, is smaller than the number of steps from the origin position, which is the position information of the target position variable θ2 (YES in S52), a control signal for rotating one step in the valve-opening direction from the current position is output (S54). Then, once the output of the control signals in steps S53 and S54 is completed, the current position of the rotor 13 is stored in the current position variable θ1 (S55).

[0032] Steps S51 to S55 are repeatedly executed, and when the current position variable θ1 and the target position variable θ2 become equal (YES in S51), that is, when the rotor 13 reaches the target position according to the command data, the status flag FLG1 is set to "0" as the discrimination information (S37). Then, the discrimination information set in the status flag FLG1 is stored in the EEPROM 36D as third backup data (S38).

[0033] This completes the position control process (S14), and the system returns to a standby state (NO loop at S13) where it waits for external command data, as shown in Fig. 4, and the above process is repeated every time external command data is given. Note that program PG1 ends when the power supply to the electrical system including the air conditioner is cut off by the ignition switch of the vehicle, when the power supply to the air conditioner is cut off by turning off the air conditioner switch, or when an abnormality such as a momentary interruption in the electrical system occurs.

[0034] Here, the discrimination information stored in the status flag FLG1 by the position control process (S14) functions as discrimination information for discriminating whether the motor 12 is operating or in a state immediately before operating (hereinafter collectively referred to as the "operating state"), or is in a non-operating state. Furthermore, in the position control process (S14), while the motor 12 is operating, the actual rotor 13 can be positioned between the current position of the program PG1 specified by the current position variable θ1 and the target position specified by the target position variable θ2. Therefore, by storing the position information based on the current position variable θ1 and the target position variable θ2 together with the discrimination information of the status flag FLG1 as first to third backup data in the EEPROM 36D, the backup data of the position information based on the current position variable θ1 and the target position variable θ2 can be effectively used in the special initialization process (S101) described in detail below.

[0035] 5, when a special initialization process (S101) is executed, a backup data acquisition process (S21) is first performed. In this process (S21), first backup data, which is position information of the current position of the rotor 13 stored in the EEPROM 36D, is stored in a variable θ11, second backup data, which is position information of the target position of the rotor 13 stored in the EEPROM 36D, is stored in a variable θ12, and third backup data, which is discrimination information stored in the EEPROM 36D, is set in FLG11.

[0036] Hereinafter, the variable name of "θ11" will be referred to as "backup current position variable θ11", the variable name of "θ12" will be referred to as "backup target position variable θ12", and "FLG11" will be referred to as "backup status flag FLG11".

[0037] Next, it is determined whether the backup status flag FLG11 is "0" (S22). That is, it is determined whether the rotor 13 was in an operating state or an inoperating state the previous time the power supply to the flow control valve 11 was stopped. If the backup status flag FLG11 is "1," a special position control process (S105) consisting of the following steps S23, S24, S25, and S28 is executed. First, it is determined whether the number of steps from the origin position, which is the position information of the backup current position variable θ11, is smaller than the number of steps from the origin position, which is the position information of the backup target position variable θ12 (S23). That is, it is determined whether the current position based on the position information of the backup current position variable θ11 is closer to the origin position than the target position based on the position information of the backup target position variable θ12. If the current position based on the backup current position variable θ11 is farther from the origin position than the target position based on the backup target position variable θ12 (NO in S23), the value obtained by adding the additional rotation angle θa to the current position based on the backup current position variable θ11 is stored as the target rotation angle θx (S24).

[0038] On the other hand, if the current position based on the backup current position variable θ11 is closer to the origin position than the target position based on the backup target position variable θ12 (YES in S23), the value obtained by adding the additional rotation angle θa to the target position based on the backup target position variable θ12 is stored as the target rotation angle θx (S25).

[0039] Then, when a value is stored in the target rotation angle θx (S24 or S25), a control signal corresponding to the target rotation angle θx is output from the CPU 36A (S28), as in the normal initialization process (S100), and then the current position of the rotor 13 is stored in the variable θ1 as the origin position (S29).

[0040] In this way, the special position control process (S105) included in the special initialization process (S101) determines the target rotation angle θx based on the position information stored in EEPROM 36D, so the amount of rotation can be made smaller than in the normal initialization process (S100), which rotates the rotor 13 at the target rotation angle θx, which is the maximum rotatable angle θmax of the rotor 13 plus the additional rotation angle θa.

[0041] The additional rotation amount θa added in the normal initialization process (S100) and the special initialization process (S101) is the same, but may be different.

[0042] Furthermore, in the initial position setting process (S12), if there is no external origin setting command (NO in S20) and the backup status flag FLG11 is "0" (YES in S22), the origin restoration process (S26) is performed.

[0043] In the origin restoration process (S26), the position information of the backup target position variable θ12 is stored in the current position variable θ1. Then, by storing the position information in the current position variable θ1, the origin position is automatically set. Specifically, as described above, the position information specifies the current position of the rotor 13 as, for example, the "number of steps away from the origin position." Therefore, the position that is away from the current position of the rotor 13 on the valve-closing side by the "number of steps away from the origin position," which is the position information of the current position variable θ1, is set as the origin position. In other words, the initial position, which is the position of the rotor 13 that is first recognized after power is turned on to the control device 30A, is set as the origin position.

[0044] Here, the special initialization process (S101) or the origin restoration process (S26) is performed on the condition that the power is restored after being stopped due to, for example, a momentary power interruption. Specifically, when the power to the electrical system including the air conditioner is turned on by the automobile ignition switch and when the power to the air conditioner is turned on by the air conditioning switch, an origin setting command is issued from the outside based on the power being turned on, whereas in the case of a momentary power interruption in the electrical system, no origin setting command is issued from the outside. That is, in step S20, it is determined whether or not there has been a momentary power interruption, and if there has been a momentary power interruption, the special initialization process (S101) or the origin restoration process (S26) is performed.

[0045] In this embodiment, a special initialization process (S101) or origin restoration process (S26) is executed when the device returns from a momentary power outage, but this is not limited to this, and the process may also be executed, for example, when the power is turned on or the device returns from the sleep state as described above, and no origin setting command is issued.

[0046] When executing the above program PG1, the CPU 36A functions as an execution control unit 40, a normal initialization unit 42, a special initialization unit 43, an origin restoration unit 44, a backup unit 45, a position control unit 46, etc., as shown in the block diagram of Figure 7.

[0047] The position control unit 46 determines a target rotation angle θx corresponding to the command data from the command data and a data table provided from the outside. The control signal generation unit 47 then generates excitation patterns PA, Pa, PB, and Pb (see FIG. 3) for rotation at the target rotation angle θx, and outputs them as on / off control signals ZA, Za, ZB, and Zb to the switches 31A, 31a, 32B, and 32b.

[0048] The backup unit 45 writes the position information stored in the current position variable θ1, the position information stored in the target position variable θ2, and the discrimination information set in the status flag FLG1 to the first to third backup data of the EEPROM 36D each time the target position is updated, and also writes the discrimination information set in the status flag FLG1 each time the current position is updated.

[0049] Each time the power is turned on, the execution control unit 40 determines whether to operate the normal initialization unit 42, the special initialization unit 43, or the origin restoration unit 44 based on the presence or absence of command data from outside and the information stored in the EEPROM 36D.

[0050] The normal initialization unit 42 determines a target rotation angle θx from a preset maximum rotatable angle θmax and an additional rotation angle θa, and performs the same processing as the control signal generation unit 47 using the target rotation angle θx.

[0051] The special initialization unit 43 has a special position control unit 49 that determines which of the current position and the target position stored in the EEPROM 36D is located farther from the origin position, and determines a target rotation angle θx by adding an additional rotation angle θa to the farther position information.The special position control unit 49 then performs the same processing as the control signal generation unit 47 using the target rotation angle θx determined by the special position control unit 49.

[0052] The origin restoration unit 44 reads the position information of the backup target position variable θ12 as the current position, and sets it as the current position of the rotor 13.

[0053] This completes the description of the configuration of this embodiment. Next, the effects of this embodiment will be described. According to the control device 30A, program PG1, and control method for the flow control valve 11 of this embodiment, the current position of the rotor 13 and the target position to which it is to be moved are stored in the EEPROM 36D. Therefore, when power is turned on, information on two stored positions, consisting of the current position of the rotor 13 at the time of the previous power outage and the target position to which it is to be moved, can be obtained from the EEPROM 36D. Furthermore, when power is turned on, either a normal initialization process (S100) or a special initialization process (S101) is performed in response to an external command. In the normal initialization process (S100), full-range movement control is performed as in the conventional method, but when the special initialization process (S101) is performed, the rotor 13 is controlled to move from the origin position of the two stored positions (i.e., the stored position farthest from one end of the movable range of the rotor 13) as the start point and a virtual position farther from the stored position than the origin position as the end point, thereby pressing the stoppers 19A and 19S1 together. This makes it possible to perform movement control for a smaller amount of movement than in the conventional method, which always performed full-range movement control of the rotor 13 every time initialization is performed, and the initialization process time can be shortened compared to the conventional method.

[0054] Furthermore, by shortening the initialization time compared to conventional methods, it is possible to reduce the power required for the initialization process and the noise generated during the initialization process. Furthermore, wear on moving parts is suppressed, thereby extending the life of the flow control valve 11.

[0055] Furthermore, in the control device 30A of this embodiment, the current position or the target position is saved in the EEPROM 36D each time it is updated. Therefore, even if the power to the flow control valve 11 is cut off unintentionally due to a momentary power outage or other reason, when the power is restored, the current position or the target position stored in the EEPROM 36D can be used to press the stoppers 19A and 19S1 together with movement control of the rotor 13 with a smaller movement amount than conventionally.

[0056] Furthermore, the previous time the power supply to the flow control valve 11 was cut off, on the condition that the rotor 13 was not moving, the origin restoration process (S26) is executed and the storage position in the EEPROM 36D is set to the current position of the rotor 13, and no special initialization process (S101) is performed, which also shortens the initialization process time compared to the conventional method. In addition, the origin restoration process (S26) is performed when the cause of the power supply cutoff is a momentary interruption, which speeds up recovery from the momentary interruption.

[0057] The discrimination information for determining whether the movement of the movable part has been completed may be a flag as in this embodiment, or may be whether the current position and the target position are the same as in the second embodiment.

[0058] 8, the drive process (S50) of the position control process (S14) differs from that of the first embodiment. In the drive process (S50) of the first embodiment, the rotor 13 is rotated step by step from the current position to reach the target position, whereas in the drive process (S50) of the present embodiment, the rotor 13 is rotated by the target rotation angle θx from the current position to the target position.

[0059] Specifically, first, the angle required to rotate the rotor 13 from the current position based on the current position variable θ1 to the target position based on the target position variable θ2 is stored as the target rotation angle θx (S34). Then, similar to step S28 described above, a control signal is output to rotate the rotor 13 by the target rotation angle θx (S35). After that, when the output of the control signal is completed, the position information stored in the target position variable θ2 is stored in the current position variable θ1 (S36). That is, assuming that the actual current position of the rotor 13 matches the target position according to the command data, the position information stored in the target position variable θ2 is stored in the current position variable θ1, and the position information stored in the current position variable θ1 and the position information stored in the target position variable θ2 become the same.

[0060] Third Embodiment This embodiment is shown in FIGS. 9 and 10, and differs from the first embodiment in part of the initial position setting process (S12) and the position control process (S14).

[0061] 10, in the position control process (S14) of this embodiment, in the backup process (S33), the determination information of the status flag FLG1 is not backed up to the EEPROM 36D, but only the position information of the current position variable θ1 and the position information of the target position variable θ2. Furthermore, in the drive process (S50) that is subsequently executed, instead of backing up when the rotor 13 has reached the target position as in the first embodiment, the position information stored in the current position variable θ1 is saved in the EEPROM 36D as first backup data every time the current position variable θ1 is updated in step S55 (S56).

[0062] 9, in the initial position setting process (S12), first and second backup data from the EEPROM 36D are stored in the backup current position θ11 and the backup target position θ12 in step S40, and then it is determined whether the backup current position θ11 and the backup target position θ12 are the same (S41). If the backup current position θ11 and the backup target position θ12 are different (NO in S41), a special initialization process (S101) is executed as in the first embodiment. If the backup current position θ11 and the backup target position θ12 are the same (YES in S41), the origin restoration process (S26) stores the position information of the backup current position θ11 in the current position variable θ1.

[0063] In this manner, in this embodiment, the operating state of the motor 12 is determined based on the current backup position θ11 and the target backup position θ12, and the same effects as in the first embodiment can be achieved. Also, in this embodiment, each time the current position is updated, the position information is stored in the EEPROM 36D, so the difference between the current position and the target position is small, and movement control can be performed with a smaller movement amount than in the special initialization process (S101) in the first embodiment.

[0064] 11, this embodiment is configured by applying the drive control process (S50) of the second embodiment to the drive process (S50) of the position control process (S14) of the third embodiment. In the position control process (S14) of this embodiment, after the drive control process (S50) is completed, the position information stored in the current position variable θ1 is saved as first backup data in the EEPROM 36D (S43) every time the current position variable θ1 is updated, as in step S56 described above.

[0065] [Other Embodiments] In the above embodiment, an example was shown in which the program PG1 is stored in a mask ROM 36C as a storage medium, but any non-volatile memory may be used, such as an EEPROM, a flash memory, a USB memory, an SSD, an HDD, a CD-ROM, etc.

[0066] In the above embodiment, an EEPROM is used as an example of a non-volatile memory for storing the current position, the target position, etc., but any writable non-volatile memory other than an EEPROM may be used, such as a flash memory, a USB memory, an SSD, or an HDD.

[0067] In the above embodiment, a backup process (S33) is performed to save the current position or the target position in the EEPROM 36D each time the position is updated, but the backup process may be performed only when the power is turned off. Also, the backup process may be performed only when a normal power-off process such as turning off the power switch is performed, or only when there is a momentary power outage, or both.

[0068] Although the motor 12 in the above embodiment is a stepping motor, it does not have to be a stepping motor as long as it is a motor that requires setting of the origin position, and may be, for example, a DC motor including a brushed motor or a brushless motor, or a servo motor equipped with a resolver as a rotation sensor. Furthermore, the stepping motor is not limited to the above embodiment, and may be a bipolar type, or may be a three-phase or five-phase type other than two-phase.

[0069] Furthermore, the drive method of the drive circuit 33 of the control device 30A is not limited to the above embodiment, and may be, for example, a one-pulse input method in which the rotation direction is determined depending on whether the level of the rotation direction input section is high or low when a signal is input to the step input section, or a two-pulse input method in which the rotation direction is determined depending on whether the terminal to which the signal is input is the forward input terminal or the reverse input terminal.

[0070] In the above embodiment, the position information of the rotor 13 is used as a variable in the program PG1, but this is not limiting, and for example, a variable that manages the actual movement distance of the valve element 18 may be used.

[0071] <Supplementary Notes> Below, the group of features extracted from the above embodiment will be explained, indicating, as necessary, the effects, etc. Note that, for ease of understanding, the corresponding configurations in the above embodiment will be indicated in parentheses as appropriate below, but these group of features are not limited to the specific configurations indicated in parentheses.

[0072] [Feature 1] After the movable part (13) of the flow control valve (11) is positioned at one end of the movable range and the stoppers (19A, 19S1) are pressed against each other, an initialization process (S101) is performed to set the current position of the movable part (13) to an origin position, a position control process (S14) is performed to acquire information on a target position based on the origin position and control the position of the movable part (13) so that the movable part (13) moves from the current position to the target position, and a non-volatile storage (S15) is performed to store the current position and the target position, which is the destination of the movement of the movable part (13) from the current position. and a special position control process (S105) that is included in the initialization process (S101) and controls the position of the movable part (13) so that the movable part (13) moves from the starting point of the memory position farther from the origin position out of two memory positions consisting of the current position and the target position stored in the non-volatile memory part (36D) to the origin position or a virtual position farther from the memory position than the origin position as an end point.

[0073] [Feature 2] The control device (30A) according to Feature 1, configured to perform the backup process (S33) every time the current position or the target position is updated.

[0074] [Feature 3] The control device (30A) according to Feature 1 or 2 is configured to store, in the backup process (S33), discrimination information for determining whether or not the movement of the movable part (13) has been completed in the nonvolatile storage unit (36D), and, on the condition that the discrimination information stored in the nonvolatile storage unit (36D) at the time of power-on of the flow control valve (11) indicates the completion of the movement of the movable part (13), perform an origin restoration process (S26) for setting the memory position of the memory in the nonvolatile storage unit (36D) to the current position of the movable part (13) instead of performing the initialization process (S101).

[0075] [Feature 4] The control device (30A) according to Feature 3, wherein the origin restoration process (S26) is performed on the condition that the power supply stoppage is due to a momentary interruption.

[0076] [Feature 5] A valve device (10) comprising: the control device (30A) according to any one of Features 1 to 4; and a flow control valve (11) controlled by the control device (30A).

[0077] [Feature 6] The computer (36A) of the control device (30A) of the flow control valve (11) is configured to: (a) set a current position of the movable part (13) to an origin position after the movable part (13) of the flow control valve (11) is positioned at one end of the movable range and the stoppers (19A, 19S1) are pressed against each other; (b) acquire information on a target position based on the origin position, and perform position control so that the movable part (13) moves from the current position to the target position; and (c) acquire information on the current position and the distance of the movable part (13) from the current position. a backup unit (45) configured to save the current position and the target position, which are destinations of movement, in a non-volatile storage unit (36D), and a special position control unit (49) included in the initialization unit (43) and configured to control the position of the movable part (13) so that the stored position farthest from the origin position, of two stored positions consisting of the current position and the target position stored in the non-volatile storage unit (36D), is a start point, and the origin position or a virtual position farther from the stored position than the origin position is an end point. [Feature 7] The program (PG1) according to Feature 6 causes the computer (36A) to function such that the backup unit (45) saves the current position and the target position in the non-volatile storage unit (36D) every time the current position or the target position is updated.

[0078] [Feature 8] The program (PG1) according to Feature 6 or 7, wherein the backup unit (45) causes the computer (36A) to function to store, in the nonvolatile storage unit (36D), discrimination information for determining whether or not the movement of the movable part (13) has been completed, and causes the computer (36A) to function as an origin restoration unit (44) that sets the memory position of the nonvolatile storage unit (36D) to a current position of the movable part (13) instead of operating the initialization unit (43), on the condition that the discrimination information stored in the nonvolatile storage unit (36D) at the time of power-on of the flow control valve (11) means that the movement of the movable part (13) has been completed.

[0079] [Feature 9] The program (PG1) according to Feature 8, which causes the computer (36A) to function so that the origin restoration unit (44) operates on the condition that the power supply interruption is a momentary interruption.

[0080] [Feature 10] A storage medium (36C) that stores the program (PG1) according to any one of Features 6 to 9.

[0081] [Feature 11] After the movable part (13) of the flow control valve (11) is positioned at one end of the movable range and the stoppers (19A, 19S1) are pressed against each other, an initialization process (S101) sets the current position of the movable part (13) to an origin position, a position control process (S14) acquires information on a target position based on the origin position and controls the position of the movable part (13) so that the movable part (13) moves from the current position to the target position, and a position control process (S15) acquires information on the current position and the target position to which the movable part (13) is to move from the current position. A control method comprising: a backup process (S33) for saving the current position and the target position in a non-volatile memory unit (36D); and a special position control process (S105) included in the initialization process (S101) for controlling the position of the movable part (13) so that the movable part (13) moves from the starting point of the memory position farther from the origin position out of two memory positions consisting of the current position and the target position stored in the non-volatile memory unit (36D) to the origin position or a virtual position farther from the memory position than the origin position as an end point.

[0082] [Feature 12] The control method according to Feature 11, wherein the backup process (S33) is performed every time the current position or the target position is updated.

[0083] [Feature 13] In the control method according to Feature 11 or 12, in the backup process (S33), determination information for determining whether or not the movement of the movable part (13) has been completed is saved in the nonvolatile storage unit (36D), and, on the condition that the determination information stored in the nonvolatile storage unit (36D) at the time of power-on of the flow control valve (11) indicates the completion of the movement of the movable part (13), an origin restoration process (S26) is performed to set the memory position stored in the nonvolatile storage unit (36D) to a current position of the movable part (13) instead of performing the initialization process (S101).

[0084] [Feature 14] The control method according to Feature 13, wherein the origin restoration process (S26) is performed on the condition that the power interruption is a momentary interruption.

[0085] In the control device of Feature 1, the valve device of Feature 5, the program of Feature 6, and the control method of Feature 11, the current position of the movable part and the target position to which it is to be moved are stored in a non-volatile storage unit. Therefore, when power is turned on, information on two stored positions, consisting of the current position of the movable part at the time of the previous power-off and the target position to which it is to be moved, can be obtained from the non-volatile storage unit. Then, when performing initialization processing, the position of the movable part is controlled so that the movable part moves from the stored position farthest from the origin position (i.e., one end of the movable part's range of motion) as the starting point and a virtual position further away from the origin position or the stored position than the origin position as the end point, thereby pressing the stoppers together. This allows for movement control of a smaller amount of movement than in the conventional method, in which the movable part is always controlled to move over the entire range to reliably press the stoppers together each time initialization processing is performed, thereby reducing the initialization processing time compared to the conventional method.

[0086] Furthermore, by shortening the initialization time compared to conventional methods, it is possible to reduce the power required for the initialization process and the noise generated during the initialization process. Furthermore, wear on moving parts is suppressed, thereby extending the life of the flow control valve.

[0087] In the control device of Feature 2, the program of Feature 7, and the control method of Feature 12, the current position or the target position is saved in a non-volatile memory unit each time the current position or the target position is updated. Therefore, even if the power to the flow control valve is cut off unintentionally due to a momentary power outage or other reason, the current position or the target position stored in the non-volatile memory unit can be used when the power is restored as described above, and the stoppers can be pressed together using movement control with a smaller movement amount of the moving parts than before.

[0088] In the control device of Feature 3, the program of Feature 8, and the control method of Feature 13, determination information for determining whether movement of the movable part has been completed is stored in a nonvolatile storage unit. Then, on the condition that movement of the movable part has been completed when the power is turned off, the storage position in the nonvolatile storage unit is set to the current position of the movable part, and initialization processing is not performed, so that the time required for initialization processing can be shortened compared to conventional methods.

[0089] In the control device of Feature 4, the program of Feature 9, and the control method of Feature 14, the storage position of the nonvolatile storage unit is set to the current position of the movable part, and initialization processing is not performed, provided that the movement of the movable part is completed when the power is stopped and the power stop is a momentary interruption. This allows for quick recovery from a momentary interruption. Note that while the above processing is performed when recovering from a momentary interruption, the above processing may also be performed at times other than when recovering from a momentary interruption (for example, when the power is turned on normally).

[0090] Although the present specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone.

[0091] 10 Valve device 11 Flow control valve 12 Motor 13 Rotor (moving part) 19A, 19S1 Stopper 30A Control device 36A CPU (computer) 36C Mask ROM (storage medium) 36D EEPROM (non-volatile storage part) 42 Normal initialization part 43 Special initialization part 44 Origin restoration part 45 Backup part 46 Position control part 49 Special position control part PG1 Program S14 Position control processing S33 Backup processing S100 Normal initialization processing S101 Special initialization processing S105 Special position control processing

Claims

1. The flow control valve's movable part is positioned at one end of its range of motion, and the stoppers are pressed against each other. Then, an initialization process is performed to set the current position of the movable part to the origin position. A position control process that acquires information on the target position relative to the origin position and controls the position of the movable part so that it moves from the current position to the target position, A backup process that stores the current position and the target position, which is the destination of the movable part from the current position, in a non-volatile memory unit. The initialization process includes a special position control process that controls the position of the movable part so that it starts from the storage position furthest from the origin position among two storage positions consisting of the current position and the target position stored in the non-volatile storage unit, and ends at the origin position or a virtual position further from the storage position than the origin position, A control device configured to perform the following actions.

2. The control device according to claim 1, configured to perform the backup process each time the current position or the target position is updated.

3. In the backup process, discrimination information for determining whether or not the movement of the movable part has been completed is stored in the non-volatile storage unit. The control device according to claim 1, which is configured to perform an origin restoration process to set the storage position of the storage in the non-volatile storage to the current position of the movable part, instead of performing the initialization process, provided that the discrimination information stored in the non-volatile storage unit at the time of power-up of the flow control valve means that the movement of the movable part has been completed.

4. The control device according to claim 3, wherein the origin restoration process is performed on the condition that the power outage is momentary.

5. A control device according to any one of claims 1 to 4, A valve device comprising a flow control valve controlled by the control device described above.

6. The computer for the control device of the flow control valve, An initialization unit is configured such that the movable part of the flow control valve is positioned at one end of its range of motion, the stoppers are pressed together, and then the current position of the movable part is set to the origin position. A position control unit is configured to acquire information on a target position relative to the origin position and to control the position of the movable part so that it moves from the current position to the target position. A backup unit is configured to store the current position and the target position, which is the destination of the movable part from the current position, in a non-volatile storage unit. A special position control unit is included in the initialization unit and is configured to control the position of the movable unit so that it starts from the storage position furthest from the origin position among two storage positions consisting of the current position and the target position stored in the non-volatile storage unit, and ends at the origin position or a virtual position further from the storage position than the origin position, A program that makes it function as such.

7. The program according to claim 6, which causes the computer to function such that the backup unit stores the current position and the target position in the non-volatile storage unit whenever the current position or the target position is updated.

8. The backup unit causes the computer to function in such a way that it stores in the non-volatile storage unit discrimination information for determining whether or not the movement of the movable part has been completed, The program according to claim 6, which, instead of operating the initialization unit, causes the computer to function as an origin restoration unit that sets the storage position of the storage in the non-volatile storage unit to the current position of the movable unit, on the condition that the discrimination information stored in the non-volatile storage unit at the time of power-up of the flow control valve means that the movement of the movable unit has been completed.

9. The aforementioned computer, The program according to claim 8, which causes the origin restoration unit to function on the condition that the power outage is momentary.

10. A storage medium for storing the program described in any one of claims 6 to 9.

11. The flow control valve's movable part is positioned at one end of its range of motion, and the stoppers are pressed against each other. Then, an initialization process is performed to set the current position of the movable part to the origin position. A position control process that acquires information on the target position relative to the origin position and controls the position of the movable part so that it moves from the current position to the target position, A backup process that stores the current position and the target position, which is the destination of the movable part from the current position, in a non-volatile memory unit. A control method comprising the initialization process, which includes a special position control process that controls the position of the movable part so that it starts from the storage position furthest from the origin position among two storage positions consisting of the current position and the target position stored in the non-volatile storage unit, and ends at the origin position or a virtual position further from the storage position than the origin position.

12. The control method according to claim 11, wherein the backup process is performed each time the current position or the target position is updated.

13. In the backup process, discrimination information for determining whether or not the movement of the movable part has been completed is stored in the non-volatile storage unit. The control method according to claim 11 or 12, provided that the determination information stored in the non-volatile memory unit when the flow control valve is powered up means that the movement of the movable part has been completed, instead of performing the initialization process, an origin restoration process is performed to set the storage position of the storage in the non-volatile memory unit to the current position of the movable part.

14. The control method according to claim 13, wherein the origin restoration process is performed on the condition that the power outage is momentary.