TWI631440B - Servo cylinder system - Google Patents

Abstract

The present invention provides a servo cylinder system that can improve the responsiveness at the start of a cylinder, and can achieve uniformity and maintenance of position control performance. The servo cylinder system (1) includes a cylinder (3), a servo valve (2), a position detection sensor (4), and a controller (5). The servo cylinder system (1) outputs to the servo valve (2) Command the voltage to move the control object (9) from the specified origin position (HP), and detect when the control object (9) leaves the teaching position (X1, X2) by a predetermined amount from the origin position (HP) The driving start command voltages (Y1, Y2) are stored and stored. When an operation instruction is output to move the control object (9) from the current position to the target position, the driving start command voltages (Y1, Y2) and the operation instruction are inputted. First, the first command voltage calculated based on the deviation is added to calculate a second command voltage, and the second command voltage is output to the servo valve (2).

Description

Servo cylinder system

The present invention relates to a servo cylinder system, which outputs a command voltage from a controller to a servo valve based on a deviation between a detected position of a control object and a target position detected by a position detection unit, thereby compressing a pressure chamber of a cylinder Supply and exhaust air to control the position of the control object.

The servo cylinder system supplies and discharges compressed air supplied to the pressure chamber of the cylinder through a servo valve, and advances and retreats the control object with respect to the cylinder. The position of the control object is detected by the position detection unit. The controller inputs the detection position detected by the position detection unit, compares it with the target position, and performs PID control on the command voltage output to the servo valve based on their deviation, thereby performing feedback control on the position of the control object. This servo cylinder system is compact, lightweight, and low in cost, and is therefore used in a wide range of fields represented by semiconductor manufacturing equipment (for example, refer to Patent Document 1, Patent Document 2, etc.).

Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. 7-35107

Patent Document 2: Japanese Patent Application Laid-Open No. 2006-57724

However, the conventional servo cylinder system has the following problems. For example, when a servo cylinder system is used in a semiconductor manufacturing facility, with the miniaturization of semiconductors, the servo cylinder system is required to control the position of a control object with high accuracy. However, the servo cylinder system has different responsiveness among products due to different characteristics of the cylinder, servo valve, and position detection unit, so it is not easy to make the position control performance uniform among products. In addition, the servo cylinder system may be deteriorated in response to changes such as abrasion of a sliding portion of a cylinder or a servo valve over a long period of time, and thus may not be able to maintain position control performance.

In the past, in order to allow the difference and change of the responsiveness of the servo cylinder system, or to eliminate the difference and change of the responsiveness, the controller needs to adjust the PID parameters. However, with the former, the position control accuracy of the servo cylinder system is reduced. For the latter, adjustment of the PID parameters is complicated and adjustment takes a lot of time.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide a servo cylinder system which can improve the responsiveness, thereby achieving uniformity and maintenance of position control performance.

In order to solve the above-mentioned problems, one embodiment of the present invention has the following configuration.

(1) A servo cylinder system comprising: a cylinder that advances and retreats a control object in a linear direction according to the pressure of a pressure chamber; a servo valve that supplies and discharges compressed air to the pressure chamber; and a position detection unit that detects A position; and a controller that inputs a detection position detected by the position detection unit To determine a deviation from the target position, and output a command voltage to the servo valve based on the deviation, characterized in that the controller includes a teaching unit that outputs a command voltage to the servo valve so that the control object A command voltage when the control object moves from a predetermined origin position and a predetermined amount of the teaching position moves away from the origin position by a predetermined amount, and stores it as a drive start command voltage; and a voltage adjustment unit at start-up, which When an operation instruction to move the control object from the current position to the target position is input, the driving start instruction voltage is added to the first instruction voltage calculated first based on the deviation after the operation instruction is input and calculated. The second command voltage is output, and the second command voltage is output to the servo valve.

Here, "moving from a predetermined origin position" includes a case where a control object is moved from a predetermined origin position to a direction extending from a cylinder, and a control object is moved from a predetermined origin position to a direction toward the cylinder side. In some cases, the control object may be moved back and forth in such a manner that the control object moves from a predetermined origin position to a direction protruding from the cylinder and then moves back toward the cylinder side.

In the above configuration, the controller actually operates the constituent parts of the servo cylinder system through the teaching unit and outputs a command voltage to the servo valve to move the control object from the origin position. At this time, the controller detects a command voltage when the control object passes a predetermined amount of the teaching position from the origin position, and stores the command voltage as a drive start command voltage. Therefore, the drive start command voltage is a value at which the servo cylinder system can reliably start the cylinder.

When the controller inputs an operation instruction to move the control object from the current position to the target position, the controller outputs a command voltage to the servo valve based on a deviation between the detected position detected by the position detection unit and the target position. this At this time, the controller adds the driving start command voltage stored by the teaching operation described above and the first command voltage first calculated based on the deviation after the operation instruction input by the start-time voltage adjustment unit to calculate the second command. Voltage, and outputs the second command voltage to the servo valve. Since the second command voltage larger than the first command voltage is applied to the cylinder, the cylinder is started immediately when the second command voltage is output to the servo valve, so that the control object starts to move from the current position toward the target position. The cylinder and the servo valve require a large amount of force at the time of starting, but it is easy to move smoothly after starting. Therefore, after the cylinder is started, the servo cylinder system moves the control object to the target position based on the command voltage output by the controller based on the deviation between the detected position and the target position.

In this way, the servo cylinder system configured as above outputs a second command voltage greater than the first command voltage calculated based on the deviation first based on the deviation after the input of the operation instruction. Therefore, even the cylinders and servos constituting the servo cylinder system The characteristics of components such as valves differ among products or deteriorate over time, and the cylinder can be started with good responsiveness. Therefore, the servo cylinder system having the above structure can improve the responsiveness according to the characteristics and degradation state of the product, can uniformize the position control performance among the products, and can maintain the initial position control performance.

(2) In the configuration described in (1), it is preferable that the teaching unit sets the teaching position to a small difference in the drive start command voltage generated based on a position of the control object before moving to the origin position. In the range.

In the above configuration, regardless of where the control object stops at the start of the teaching operation, the difference in the drive start command voltage detected by the teaching operation Both are small. Therefore, regardless of the position of the control object during the teaching operation, when the control object is moved to the target position, it is possible to output to the servo valve the first instruction calculated based on the deviation first after the operation instruction is input. The second command voltage with a large voltage causes the cylinder to start immediately. Thus, according to the above configuration, it is possible to improve the responsiveness without changing the control of the teaching operation and the normal operation according to the position of the control object.

(3) In the configuration described in (1) or (2), the teaching unit preferably includes a preparation unit that outputs a command voltage to the servo valve before moving the control object to the origin position, The control object is moved to a maximum extension position that is maximally extended toward the opposite side of the cylinder.

In the above configuration, since there is a sufficient distance for stable control during teaching operation, the amount of overshoot can be reduced compared to a case where the control object reaches the origin position from a position other than the maximum extended position. , So that the control object can reach the origin position as soon as possible. Thus, according to the above configuration, the control object can be brought to the origin position with high accuracy in a short time.

Therefore, according to the present invention, it is possible to provide a servo cylinder system that can improve the responsiveness at the time of starting the cylinder, and can achieve uniformity and maintenance of the position control performance.

1‧‧‧Servo cylinder system

2‧‧‧Servo valve

3‧‧‧ cylinder

4‧‧‧Position detection sensor (an example of a position detection unit)

5‧‧‧controller

5a‧‧‧Tutorial (example of teaching unit and preparation unit)

5b‧‧‧Normal operation program (an example of a voltage adjustment unit at startup)

9‧‧‧ Control Object

32‧‧‧Pressure chamber

HP‧‧‧ origin position

X1‧‧‧First teaching position (an example of teaching position)

X2‧‧‧Second teaching position (an example of teaching position)

Y1‧‧‧falling drive start command voltage (an example of drive start command voltage)

Y2‧‧‧ rising drive start command voltage (an example of drive start command voltage)

FIG. 1 is a circuit diagram of a servo cylinder system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a tutorial type.

FIG. 3 is a graph illustrating a teaching operation. Time is shown on the horizontal axis, position is shown on the left vertical axis, and command voltage is shown on the right vertical axis.

FIG. 4 is a diagram illustrating a difference in a cylinder operation method due to a difference in a movement start position of a control object.

FIG. 5 is a diagram for explaining the difference in drive start command voltages for raising and lowering due to differences in the position of a control object at the start of a teaching operation.

FIG. 6 is an enlarged view of part A of FIG. 5.

FIG. 7 is a diagram showing results of a teaching of a predetermined movement amount.

FIG. 8 is a diagram showing the results of a teaching position test.

FIG. 9 is a flowchart showing a normal operation program.

Hereinafter, an embodiment of a servo cylinder system according to the present invention will be described based on the drawings. In the following description, a schematic configuration of the servo cylinder system 1 will be described first. Next, the teaching operation will be described. Then, the normal operation will be described. The reason for moving the control object 9 to the lower limit position at the start of the teaching operation and then to the origin position HP will be described below. Next, a method of determining the teaching predetermined movement amount Z and the first and second teaching positions X1 and X2 (an example of the teaching position) will be described. Finally, the operational effects of the servo cylinder system 1 according to this embodiment will be described.

<Outline Configuration of Servo Cylinder System>

FIG. 1 is a circuit diagram of a servo cylinder system 1 according to an embodiment of the present invention. The servo cylinder system 1 includes a servo valve 2, a cylinder 3, a position detection sensor 4, and a controller 5. The servo cylinder system 1 controls the position of a control object 9. The servo cylinder system 1 is characterized in that the instruction formula 5a (reference Refer to FIG. 2 described later) and the normal operation program 5b (especially the start-up voltage adjustment means shown in S26 to S29 and S31 of FIG. 9 described later).

As shown in FIG. 1, the air cylinder 3 is arrange | positioned so that the control object 9 may advance and retreat in an up-down direction. In the cylinder 3, a piston 33 is slidably mounted in the cylinder body 31. The pressure chamber 32 of the cylinder body 31 is air-tightly divided into a first pressure chamber 32 a and a second pressure chamber 32 b by the piston 33. The cylinder body 31 is formed with a first operation port 31a for communicating with the first pressure chamber 32a, and a second operation port 31b is opened for communicating with the second pressure chamber 32b. In the cylinder 3, the first and second operation ports 31a and 31b are connected to the servo valve 2 via the first and second supply and exhaust passages 6b and 6c, so that the internal pressure of the first and second pressure chambers 32a and 32b can be controlled. . An output rod 34 is connected to the piston 33. The control article 9 is coupled to the front end portion of the output lever 34 and advances and retracts integrally with the piston 33.

In such a cylinder 3, the difference between the downward force caused by the internal pressure of the first pressure chamber 32a plus the force obtained by controlling the weight of the article 9 and the upward force caused by the internal pressure of the second pressure chamber 32b The piston 33 performs a reciprocating linear motion in the cylinder body 31, so that the control object 9 is lowered (extended) or raised (retreated). The position detection sensor 4 is mounted on the side of the cylinder body 31 and detects the position of the control object 9 from the position of the piston 33.

The servo valve 2 is a known directional switching valve. The servo valve 2 is configured such that when a command voltage output from the controller 5 is applied to the electromagnetic solenoid 23, the valve element 22 moves in the housing 21 in proportion to the command voltage, so that the first port 21a, the first The communication states between the second port 21b, the third port 21c, and the exhaust flow path 21d are switched.

The first to third ports 21 a to 21 c are opened in the case 21. First mouth 21a It is connected to a compressed air supply source via an input passage 6a. The second port 21b is connected to the first operation port 31a of the cylinder 3 via the first supply / discharge passage 6b. The third port 21c is connected to the second operation port 31b of the cylinder 3 via the second supply / discharge passage 6c. The exhaust flow path 21d is connected to an exhaust port (not shown). When no command voltage is applied to the electromagnetic solenoid 23, the valve element 22 is disposed in a neutral state in which neither of the first port 21a, the second port 21b, or the third port 21c is communicated by the compression springs 24 and 25. position. In this state, the servo valve 2 does not supply or exhaust compressed air to or from the first and second pressure chambers 32a, 32b. In this case, since the control article 9 is coupled to the lower end portion of the output rod 34 in the cylinder 3, the piston 33 is lowered by the weight of the control article 9 and abuts against the lower end surface of the cylinder body 31.

On the other hand, when the command voltage is applied to the solenoid 23, the valve element 22 moves toward the first position or the second position according to the command voltage. In the first position, the second port 21b communicates with the first port 21a, and the third port 21c communicates with the exhaust flow path 21d. In this case, in the cylinder 3, since the compressed air is supplied to the first pressure chamber 32a and the compressed air is discharged from the second pressure chamber 32b, the control article 9 is lowered. In the second position, the third port 21c communicates with the first port 21a, and the second port 21b communicates with the exhaust flow path 21d. In this case, since the compressed air is supplied to the second pressure chamber 32b and the compressed air is discharged from the first pressure chamber 32a in the cylinder 3, the control article 9 is raised. In addition, the servo valve 2 adjusts the opening degree by moving the valve element 22 in proportion to the command voltage, and controls the amount of compressed air supplied and exhausted.

The position detection sensor 28 detects the position of the spool 22. The comparison unit 26 and the adjustment unit 27 adjust the command voltage output from the controller 5 to the servo valve 2 so that the position of the spool 22 detected by the position detection sensor 28 is adjusted. Consistent with the command from the controller 5.

The controller 5 is a known microcomputer. The controller 5 is electrically connected to the position detection sensor 4 via the position detection line 7 so that the position of the control object (detection position) detected by the position detection sensor 4 can be input. The controller 5 is connected to the servo valve 2 via a command voltage output line 8, and can output a command voltage that controls the operation of the servo valve 2 to the servo valve 2. The controller 5 stores the instruction formula 5a and the normal operation program 5b in the memory. Details of the tutorial formula 5a and the normal operation formula 5b will be described later.

The cylinder 3 can physically lower (extend) the control object 9 until the piston 33 abuts the lower end surface of the cylinder body 31 (the position of the control object 9 at this time is referred to as a "lower end position"). In addition, the cylinder 3 can physically raise (retreat) the control article 9 until the piston 33 abuts the upper end surface of the cylinder body 31 (the position of the control article 9 at this time is referred to as an "upper end position"). The physical movement range of this control object 9 is called "physical movement range". However, the servo cylinder system 1 drives the cylinder 3 by adjusting the internal pressure of the first and second pressure chambers 32 a and 32 b to control the position of the control object 9. Therefore, the servo cylinder system 1 can control the position of the control object 9 only within a range smaller than the physical movement range. This control range is called "controllable range". Therefore, in the following description, the position of the control article 9 (the lowest position in the controllable range, which can be controlled when the piston 33 is moved to the lower end side of the cylinder body 31 to the maximum extent under the pressure of the pressure chamber 32 The position where the control object 9 is extended to the maximum) is called the "lower limit position (an example of the maximum extended position)", and the piston 33 is moved to the upper end side of the cylinder body 31 to the maximum extent under the pressure of the pressure chamber 32. Position of the control object 9 (controllable The highest position in the range and the position that can be controlled so that the control object 9 moves back to the maximum) is called the "upper limit position".

<About teaching operation>

The teaching operation will be described below with reference to FIGS. 2 and 3. FIG. 2 is a flowchart showing a tutorial formula 5a. 3 is a graph illustrating a teaching operation, showing time on the horizontal axis, the position of the control object 9 detected by the position detection sensor 4 on the left vertical axis, and the output of the controller 5 on the right vertical axis Command voltage to servo valve 2.

The teaching operation is performed by the controller 5 executing the teaching formula 5a shown in FIG. 2. In the teaching operation, the servo cylinder system 1 is actually operated to detect a drive start command voltage necessary for starting the cylinder 3 and stored in the controller 5. The teaching operation must be performed immediately after the power is turned on. Moreover, it is desirable to implement it regularly in order to maintain product performance.

The controller 5 first moves the control object 9 to the lower limit position in step 1 (hereinafter abbreviated as "S1") of FIG. 2 after the teaching operation is started. Specifically, as shown in FIG. 3, the controller 5 outputs a command voltage so that the spool 22 of the servo valve 2 moves in the direction of the first position. In the cylinder 3, the first pressure chamber 32a is pressurized and the second pressure chamber 32b is depressurized, so that the control article 9 starts to descend. The controller 5 outputs a command voltage to the servo valve 2 so that the closer the control object 9 is to the lower limit position, the cylinder 3 slows down the descending speed of the control object 9 to stop the control object 9 at the lower limit position with high accuracy.

Then, in S2 of FIG. 2, the controller 5 moves the control object 9 to the origin position (HP). Here, the origin position HP refers to a reference position at which the cylinder 3 starts when a drive start command voltage is detected. In this real In this embodiment, the upper limit position is used as the origin position HP. This process will be specifically described below. As shown in FIG. 3, the controller 5 outputs a command voltage for moving the spool 22 of the servo valve 2 in the direction of the second position. Thus, in the cylinder 3, the upward force caused by the internal pressure of the second pressure chamber 32b is greater than the downward force caused by the internal pressure of the first pressure chamber 32a plus the force obtained by controlling the weight of the article 9, Therefore, the piston 33 rises integrally with the control object 9.

As shown in S3 of FIG. 2, the controller 5 waits for 1 second after the control object 9 reaches the origin position HP. Specifically, as shown in S3 of FIG. 3, the detection position of the position detection sensor 4 is input to the controller 5, and the controller 5 outputs an instruction after confirming that the control object 9 has reached the origin position HP (upper limit position). The voltage is applied to stop the control object 9 at the origin position HP. Thereby, the command voltage and the position of the control object 9 are stabilized. The standby time can be arbitrarily set.

In S4 in FIG. 2, the controller 5 starts to lower the control object 9 and teaches the predetermined movement amount Z. Here, the teaching predetermined movement amount Z refers to a distance at which the control object 9 is lowered (extended) and raised (retreated) from the origin position HP in order to detect the drive start command voltage. The position where the control object 9 is moved from the origin position HP by the teaching predetermined movement amount Z is referred to as a "teaching predetermined moving position". The teaching predetermined movement amount Z is determined by a method described later. In this embodiment, the teaching predetermined movement amount Z is 4 mm. Specifically, as shown in FIG. 3, the controller 5 outputs a command voltage for moving the spool 22 of the servo valve 2 to the first position side. In the cylinder 3, when the downward force caused by the internal pressure of the first pressure chamber 32a plus the force obtained by controlling the weight of the article 9 is greater than the upward force caused by the internal pressure of the second pressure chamber 32b, The piston 33 starts to descend integrally with the control object 9.

The controller 5 determines whether the control object 9 has passed the first teaching position X1 in S5. Here, the first teaching position X1 is a position where the command voltage output from the controller 5 is detected when the cylinder 3 starts to lower the control object 9. The first teaching position X1 is set between the origin position HP and the first teaching predetermined movement position. The method of determining the first teaching position X1 will be described later. In the present embodiment, the position which has fallen by 0.7 mm from the origin position HP is the first teaching position X1.

As shown in FIG. 2 and FIG. 3, the controller 5 does not detect the command voltage before the control object 9 passes the first teaching position X1 (S5: NO), and outputs the command voltage to the servo valve 2 to lower the control object 9. When the control object 9 passes the first teaching position X1 (S5: YES), the controller 5 uses the command voltage currently output to the servo valve 2 as the drive start command voltage Y1 (drive start command voltage) in S6. An example). In this way, the controller 5 operates the cylinder 3, the servo valve 2, and the position detection sensor 4 constituting the servo cylinder system 1 to detect and store the driving start command voltage Y1 for descent when the cylinder 3 starts to lower the control object 9, Therefore, it is possible to identify the driving start command voltage Y1 for the fall that reflects the characteristics and state of the system components at that time.

Then, the controller 5 determines whether the control object 9 has reached the teaching predetermined movement position in S7 of FIG. 2. As shown in FIGS. 2 and 3, before the control object 9 reaches the teaching predetermined movement position (S7: NO), the controller 5 outputs a command voltage to the servo valve 2 in order for the cylinder 3 to lower the control object 9. When the controller 5 determines that the control object 9 has reached the teaching movement position (S7: YES), it waits for 4 seconds. That is, the controller 5 outputs a command voltage to the servo valve 2 to stop the control object 9 at the teaching movement position for 4 seconds. Therefore, the command voltage and control The position of the manufacturing object 9 is stable. This standby time can be arbitrarily set.

Then, in S9 of FIG. 2, the controller 5 causes the control object 9 to start rising (backward) toward the origin position HP. Specifically, as shown in FIG. 3, the controller 5 outputs a command voltage to move the spool 22 of the servo valve 2 to the second position side. In the cylinder 3, when the upward force caused by the internal pressure of the second pressure chamber 32b is larger than the downward force caused by the internal pressure of the first pressure chamber 32a plus the force obtained by controlling the weight of the article 9, the piston 33 starts to rise integrally with the control object 9.

Then, in S10 of FIG. 2, the controller 5 determines whether the control object 9 has passed the second teaching position X2. Here, the second teaching position X2 is a position where the command voltage output from the controller 5 is detected when the cylinder 3 starts to raise the control object 9. The second teaching position X2 is set between the teaching predetermined movement position and the teaching position HP. The second teaching position X2 is determined by a determination method described later. In this embodiment, the second teaching position X2 is a position that is lowered by 3.3 mm from the origin position HP (a position that is raised by 0.7 mm from the teaching predetermined movement position).

As shown in FIGS. 2 and 3, the controller 5 does not detect the command voltage output to the servo valve 2 before the control object 9 passes the second teaching position X2 (S10: NO), and outputs the command voltage to the servo valve 2 for the cylinder 3 A command voltage to raise the control object 9. When the control object 9 passes the second teaching position X2 (S10: YES), the controller 5 detects the command voltage currently output to the servo valve 2 in S11, and uses it as the drive start command voltage Y2 for rising ( An example of the drive start command voltage) is stored. As a result, the controller 5 actually uses the cylinder 3, the servo valve 2, and the position detection sensor 4 to detect the driving start command voltage for ascent. Y2 is also stored, so that it is possible to identify the driving start command voltage Y2 for the rise that reflects the characteristics and status of the system components at that time.

Then, as shown in FIG. 2, in S12, the controller 5 determines whether the control object 9 has reached the origin position HP. When the control object 9 does not reach the origin position HP (S12: No), the controller 5 continuously outputs a command voltage to the servo valve 2 as shown in FIG. 3 in order to make the cylinder 3 raise the control object 9. As shown in FIG. 2, when it is determined that the control object 9 has reached the origin position HP (S12: YES), the processing is terminated. Specifically, as shown in FIG. 3, if the position detection sensor 4 detects the upper limit position of the control object 9 via the piston 33, the controller 5 controls the command voltage of the servo valve 2 to stop at the upper limit position. In this case, the air cylinder 3 is stopped in a state where the control article 9 is disposed at the origin position HP (upper limit position). This makes it easier for the cylinder 3 and the servo valve 2 to start operation when the normal operation described later is performed.

<About normal operation>

Next, the normal operation will be described. The controller 5 executes the normal operation program 5b to move the control object 9 from the current position to the target position.

That is, as shown in S21 of FIG. 9, the controller 5 receives an operation instruction after the operator presses the start switch, for example. Then, the controller 5 confirms the current position of the control object 9 in S22. Specifically, the controller 5 inputs the detection position of the control object 9 detected by the position detection sensor 4 via the piston 33. Then, in S23, the controller 5 calculates the deviation (the distance from the current position to the target position) between the current position of the control object 9 and the target position. Then, the controller 5 determines whether the deviation is greater than 0 in S24.

When the deviation of the controller 5 is greater than 0 (S24: Yes), The command voltage corresponding to the deviation is calculated in S25. This command voltage is calculated based on the detection position of the position detection sensor 4 only, and does not reflect the drive start command voltage.

Then, in S26, the controller 5 determines whether the operation is started. Specifically, the controller 5 determines whether it is the first (first time) command voltage control after receiving the operation instruction (see S1). When the controller 5 determines that the current control operation is started (S26: YES), it determines in S27 whether the control object 9 is to be raised or lowered. The drive start command voltage (up drive start command voltage Y2, down drive start command voltage Y1) required when the cylinder 3 actually starts operation is different when the control object 9 is raised and lowered, so it is necessary to confirm Controls the direction in which the object 9 moves.

When the control object 9 is raised (S27: YES), the controller 5 calculates the second command voltage in S28, that is, the first (first time) calculation after receiving the instruction to raise the cylinder 3 The first command voltage is added to the rising drive start command voltage Y2 stored by the teaching operation to calculate a second command voltage. Then, in S29, the controller 5 outputs the second command voltage to the servo valve 2. As a result, the servo valve 2 is applied with the drive start command voltage Y2 for raising that actually starts the cylinder 3, and immediately after the operation instruction is input, the second command voltage larger than the first command voltage is applied. Therefore, in the cylinder 3, even if the characteristics of the constituent parts are different from those of other products or the constituent parts are deteriorated, it is possible to apply the second command to the servo valve 2 only by applying the first command voltage to the servo valve 2 without starting to increase. The command voltage starts to rise immediately. Therefore, from the time when the second command voltage is output until the cylinder 3 opens the control object 9 The initial response time was drastically shortened. After that, the process returns to S22.

On the other hand, when the control object 9 is lowered (S27: No), the controller 5 calculates the second command voltage in S31, that is, the controller 5 first receives the operation instruction in order to lower the cylinder 3 (first Times) The calculated first command voltage is added to the driving start command voltage Y1 for descent stored by the teaching operation to calculate a second command voltage. Then, in S29, the controller 5 outputs the second command voltage to the servo valve 2. As a result, the servo valve 2 is applied with the second drive voltage higher than the first command voltage in addition to the lowering drive start command voltage Y1 that starts the cylinder 3 to reliably descend. Therefore, in the cylinder 3, even if the characteristics of the constituent parts are different from those of other products or the constituent parts are deteriorated, the second command can be applied to the servo valve 2 only by applying the first command voltage to the servo valve 2 without starting to decrease. The command voltage starts to drop immediately. Therefore, the response time from when the second command voltage is output until the cylinder 3 lowers the control object 9 is extremely shortened. After that, the process returns to S22.

The controller 5 returns to S22 and moves the control object 9 toward the target position. Specifically, the controller 5 determines the deviation between the current position of the control object 9 and the target position in S22 to S24, and determines whether the deviation is greater than 0. Since the deviation is greater than 0 when the control object 9 does not reach the target position (S24: YES), the controller 5 calculates a command voltage corresponding to the deviation between the detection position and the target position in S25. At this point in time, since the cylinder 3 is after the start operation, rather than the start operation (not the first command voltage control after the input of the operation instruction) (S26: No), the command voltage calculated in S25 is held in S30. As it is, the second command voltage is directly output to the servo valve 2. Then return to S22. By repeating this process, the object is controlled 9Move towards the target position. That is, after the cylinder 3 starts operating, the controller 5 performs feedback control on the position of the control object 9 based on the detection position detected by the position detection sensor 4 in the same manner as the known technique. When the control object 9 reaches the target position and the deviation between the current position of the control object 9 and the target position is 0 (S24: NO), the controller 5 ends the process.

<The reason for moving the control object 9 to the lower limit position during the teaching operation and then to the origin position HP>

As shown in S1 and S2 of FIG. 2, the instruction formula 5a moves the control object 9 to the lower limit position once and then moves to the origin position HP (upper limit position). This is to allow the air cylinder 3 to move the control object 9 to the origin position HP stably for a short time during the teaching operation. This will be specifically described based on FIG. 4. FIG. 4 is a diagram illustrating a difference in a cylinder movement method due to a difference in a movement start position of a control object.

As shown in FIG. 4 (a), when the cylinder 3 moves the control object 9 from the upper end position to the origin position HP as shown in P1 in the figure, the control object 9 is lowered beyond the origin position as shown in P2 in the figure HP. Then, the air cylinder 3 raises the control object 9 toward the origin position HP as shown in P3 in the figure, and then stabilizes the control object 9 at the origin position HP.

In addition, for example, as shown in FIG. 4 (b), when the cylinder 3 moves the control object 9 from the position between the original position HP and the lower limit position to the original position HP as shown in P11 in the figure, as shown in P12 As shown, the control object 9 is raised beyond the origin position HP. Then, as shown in P13 in the figure, the air cylinder 3 lowers the control object 9 toward the origin position HP, and then stabilizes the control object 9 at the origin position HP.

As another example, as shown in FIG. 4 (c), the cylinder 3 is shown in FIG. When the control object 9 is moved from the lower limit position, since there is a sufficient distance for stable control, the amount of overshoot can be reduced, and the control object 9 can be stabilized at the origin position HP as quickly as possible.

Therefore, during the teaching operation, if the control object is moved to the lower limit position and then moved to the origin position HP, the amount of overshoot when the control object 9 reaches the origin position HP can be reduced, so that it reaches and stabilizes as soon as possible. Origin position HP.

<How to determine the teaching movement amount and teaching position>

Next, a method for determining the teaching predetermined movement amount and the teaching position will be described with reference to FIGS. 5 to 8. First, the necessity of determining the prescribed movement amount and teaching position will be explained.

The inventors performed tutorial formula 5a on one servo cylinder system 1 for the first case, the second case, and the third case, and conducted experiments to investigate the variation of the command voltage output by the controller 5. The first case is The position of the control object 9 at the beginning of the teaching action is the upper position; the second case is the position of the control object 9 at the beginning of the teaching action as the middle position between the upper end position and the lower end position; the third example is the start of the teaching action The position of the time control object 9 is the lower end position. The results are shown in Fig. 5. FIG. 5 is a diagram illustrating the difference between the driving start command voltage for ascent and descent caused by the difference in the position of the control object at the start of the teaching operation, the time is shown on the horizontal axis, and the control object 9 is shown on the left vertical axis. The position indicates the command voltage output from the controller 5 to the servo valve 2 on the right vertical axis.

As shown in FIG. 5, in the first to third examples, the position of the control object 9 is changed and the electric signal is commanded according to the position of the control object 9 when the teaching operation is started. There is a difference in pressure fluctuations.

FIG. 6 is an enlarged view of part A of FIG. 5. As shown by the solid line in the figure, in the first example, the command voltage Y11 when the control object 9 descends from the origin position HP to the first teaching position X1 is 5.225V. As shown by the dotted line in the figure, in the second example, the command voltage Y12 when the control object 9 descends from the origin position HP to the first teaching position X1 is 5.177V. As shown by the two-dot chain line in the figure, in the third example, the command voltage Y13 when the control object 9 is lowered from the origin position HP to the first teaching position X1 is 5.110V. It can be seen that according to the position of the control object 9 at the start of the teaching operation, a difference of 0.115 V occurs in the driving start command voltages Y11 to Y13 for descent.

In addition, as shown by the thin solid line in the figure, in the first example, the command voltage Y21 when the control object 9 rises from the teaching predetermined movement position to the second teaching position X2 is 4.140V. As shown by the thin dashed line in the figure, in the second example, the command voltage Y22 when the control object 9 rises from the teaching prescribed movement position to the second teaching position X2 is 4.125V. As shown by the thin two-dot chain line in the figure, in the third example, the command voltage Y23 when the control object 9 rises from the teaching prescribed movement position to the second teaching position X2 is 4.135V. It can be seen that according to the position of the control object 9 at the start of the teaching operation, a difference of 0.015 V occurs in the drive start command voltages Y21 to Y23 for ascent.

In this way, the teaching operation causes a difference in the driving start command voltage Y1 for the lowering and a driving start command voltage Y2 for the raising due to the difference in the position of the control object 9 at the start of the teaching operation. If the difference between the driving start command voltage Y1 for falling and the driving start command voltage Y2 for rising is large, there is a concern that the response at the start of the cylinder 3 cannot be improved during normal operation. specific In other words, if the control object 9 is located at the upper end position when the normal operation is started, the descending drive start command voltage Y11 (5.225 V) stored according to the first example is not output to the servo valve 2 and the cylinder 3 does not start descending. However, when the teaching operation is performed based on the third example, the cylinder 3 with the control object 9 placed at the upper end position at the start of the normal operation, even if the controller 5 outputs the descending command start voltage Y13 (5.110V) to the servo The valve 2 also had insufficient command voltage, and the cylinder 3 could not respond well and began to fall. For this reason, it is desirable to minimize the difference between the driving start command voltage Y1 for lowering and the driving start command voltage Y2 for raising caused by the position of the control object 9 as much as possible. This is to reduce unevenness in response when the cylinder 3 is started during normal operation depending on the position of the control object 9 at the start of the teaching operation.

Therefore, the inventors determined the teaching predetermined movement amount so that the difference between the driving start command voltage Y1 for descent and the driving start command voltage Y2 for descent caused by the position of the control object 9 during the teaching operation was reduced. Z and the first and second teaching positions X1, X2. This determination method will be described based on FIGS. 7 and 8.

First, a method of determining a predetermined movement amount will be described. The inventors conducted a teaching predetermined movement amount test to investigate the relationship between the teaching predetermined movement amount Z and the driving start command voltage Y1 for falling and the driving start command voltage Y2 for rising. In the teaching prescribed movement amount test, except for a point where the position of the control object 9 is different at the start of the teaching action and a point where the teaching prescribed movement amount Z is different, the driving start command voltage Y1 for falling and the rising are measured by the same teaching action. The drive start command voltage Y2 is used.

In this test, the origin position HP is the point of the upper limit position, the first The teaching position X1 is a point that is lowered by 0.7 mm from the origin position HP, and the second teaching position X2 is a position that is lowered by 3.3 mm from the origin position HP (rising from the teaching predetermined movement position The point at 0.7mm is common. At the beginning of the teaching operation, the position of the control object 9 is the upper end position, the middle position between the upper end position and the lower end position, and the point at which the lower end position is. In addition, the points at which the prescribed movement amount Z is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, and 6 mm are different.

In the test, according to the predetermined movement amount Z of each teaching, it is measured: when the position of the control object 9 is at the upper end position when the teaching operation starts, the driving start command voltage Y1 for falling and the driving start command voltage Y2 for rising are taught Lowering drive start command voltage Y1 and rising drive start command voltage Y2 when the position of the control object 9 is at the middle position at the beginning and lowering drive start when the position of the control object 9 is the lower end position when the teaching operation starts The command voltage Y1 and the rising drive start command voltage Y2. Then, the difference between the driving start command voltage Y1 for descent and the driving start command voltage Y2 for ascent based on the position of the control object 9 is calculated for each teaching movement amount Z. The results are shown in Fig. 7.

As shown in FIG. 7, when the teaching prescribed movement amount is 1 mm, the difference between the driving start command voltage Y1 for falling is 0.173V, and the difference for the driving start command voltage Y2 for rising is 0.136V. When the teaching prescribed movement amount is 2 mm, the difference between the driving start command voltage Y1 for falling is 0.096V, and the difference for the driving start command voltage Y2 for rising is 0.037V. When the teaching prescribed movement amount is 3 mm, the difference between the driving start command voltage Y1 for falling is 0.047V, and the difference for the driving start command voltage Y2 for rising is 0.014V. The amount of movement required during teaching is In the case of 4 mm, the difference between the driving start command voltage Y1 for the descent is 0.033V, and the difference between the driving start command voltage Y2 for the ascent is 0.006V. When the teaching prescribed movement amount is 5 mm, the difference between the driving start command voltage Y1 for falling is 0.036V, and the difference for the driving start command voltage Y2 for rising is 0.005V. When the teaching prescribed movement amount is 6 mm, the difference between the driving start command voltage Y1 for descent is 0.034V, and the difference for the driving start command voltage Y2 for ascent is 0.007V.

As a result, the difference (solid line) between the driving start command voltage Y1 for falling and the difference (dashed line) for the driving start command voltage Y2 for ascent are reduced in a range where the teaching prescribed movement amount Z is 1 mm or more but less than 4 mm. tendency. On the other hand, when the predetermined movement amount Z is 4 mm or more, the difference (solid line) between the driving start command voltage Y1 for falling and the difference (dashed line) for the driving start command voltage Y2 for rising are stabilized. Accordingly, by setting the predetermined movement amount Z of teaching to 4 mm or more, it is possible to make a difference between the driving start command voltage Y1 for descent and the driving start command voltage Y2 for descent according to the position of the object 9 at the start of the teaching operation. Are reduced.

Next, a method for determining the first and second teaching positions X1 and X2 will be described. The inventors conducted a teaching position test to investigate the relationship between the first and second teaching positions X1 and X2 and the command voltage. In the teaching position test, except for the point where the control object 9 was moved to the origin position HP and the point where the teaching position is different, the lower driving start command voltage Y1 and the rising driving start were detected by the same teaching operation. Command voltage Y2.

In this test, the point where the origin position HP is the upper limit position and the point where the teaching movement amount Z is 4 mm are common. The first teaching position X1 is 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, The point at the position of 0.9mm and the second teaching position X2 are the positions (from the origin position) which have risen by 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm from the teaching movement position. HP drops by 3.6mm, 3.5mm, 3.4mm, 3.3mm, 3.2mm, 3.1mm) is different.

In the test, the first and second teaching positions X1 and X2 were used to measure: when the position of the control object 9 at the start of the teaching operation is the upper end position, the driving start command voltage Y1 for descent and the driving start command voltage Y2 for ascent , When the position of the control object 9 at the start of the teaching operation is the intermediate position, the driving start command voltage Y1 for lowering and the driving start command voltage Y2 for the rising operation, and when the position of the control object 9 is the lower end position when the teaching operation starts The driving start command voltage Y1 for falling and the driving start command voltage Y2 for rising are. Then, the difference between the driving start command voltage Y1 for falling and the driving start command voltage Y2 for rising are calculated at the first and second teaching positions X1 and X2. The results are shown in Fig. 8.

As shown in FIG. 8, the first teaching position X1 is a position lowered by 0.4 mm from the origin position HP, and the second teaching position X2 is a position raised by 0.4 mm from a predetermined movement position. The difference between the driving start command voltage Y1 for falling is 0.054V, and the difference for the driving start command voltage Y2 for rising is 0.007V. At the position where the first teaching position X1 is lowered by 0.5 mm from the original position HP and the position where the second teaching position X2 is raised by 0.5 mm from the predetermined movement position, the driving start command voltage Y1 for the lowering is The difference is 0.044V, and the difference between the rising drive start command voltage Y2 is 0.006V. At the position where the first teaching position X1 has fallen by 0.6 mm from the origin position HP and the second teaching position X2 has been raised by 0.6 mm from the teaching predetermined movement position, the driving start command voltage Y1 for the descent The difference is 0.036V, and the rising drive starts The difference between the command voltage Y2 is 0.005V. At the position where the first teaching position X1 is lowered by 0.7 mm from the original position HP and the position where the second teaching position X2 is raised by 0.7 mm from the predetermined movement position, the driving start command voltage Y1 for the lowering is The difference is 0.030V, and the difference between the rising drive start command voltage Y2 is 0.007V. At the position where the first teaching position X1 is lowered by 0.8 mm from the origin position HP and the position where the second teaching position X2 is raised by 0.8 mm from the predetermined movement position, the driving start command voltage Y1 for the lowering is The difference is 0.029V, and the difference between the rising drive start command voltage Y2 is 0.006V. At the position where the first teaching position X1 is lowered by 0.9 mm from the original position HP and the position where the second teaching position X2 is raised by 0.9 mm from the predetermined movement position, the driving start command voltage Y1 is lowered. The difference is 0.030V, and the difference between the rising drive start command voltage Y2 is 0.007V.

Therefore, if the first teaching position X1 is set to be 0.4 mm or more but less than 0.7 mm from the origin position HP, the difference (solid line) of the driving start command voltage Y1 for lowering tends to decrease. However, when the first teaching position X1 is lowered by 0.7 mm or more from the origin position HP, the difference (solid line) of the driving start command voltage Y1 for lowering is stabilized. Thus, by lowering the first teaching position X1 to a position where the first teaching position X1 is lowered by 0.7 mm or more, the driving start command voltage Y1 for descent which is generated by controlling the position of the object 9 at the start of the teaching operation can be made. The difference is small.

On the other hand, the difference (dotted line) in the drive start command voltage Y2 for rising is not seen as a large difference depending on the second teaching position X2. Thereby, the second teaching position X2 can be freely determined based on the first teaching position X1. Therefore, in order to make the control easy, the second teaching position X2 is moved from the teaching predetermined movement position. It is preferable to raise the position by the same distance as the distance from the origin position HP to the first teaching position.

In this way, the teaching predetermined movement amount Z and the first and second teaching positions X1 and X2 are determined so that the driving start command voltage Y1 for lowering and the driving for ascending generated according to the position of the control object 9 at the start of the teaching operation. The difference in the start command voltage Y2 becomes smaller (stable). Therefore, even if the position of the control object 9 is different at the start of the teaching operation, the difference between the driving start command voltage Y1 for lowering and the driving start command voltage Y2 for rising can be made small. Therefore, irrespective of the position of the control object 9 during the teaching operation, when a second drive command voltage greater than the first command voltage is input to the servo valve 2 and the drive start command voltage Y1 for falling is input, the output from the first The variation in response time from the time of the two command voltages to the time when the cylinder 3 starts to lower the control object 9 can be reduced. In addition, regardless of the position of the control object 9 when the teaching operation is performed, when the second command voltage is input in addition to the drive start command voltage Y2 for rising to the servo valve 2, the second command voltage is output to the cylinder 3 Any variation in response time when the control object 9 starts to rise can be reduced.

<About effect>

As described above, in the present embodiment, the servo cylinder system 1 includes the cylinder 3 that advances and retreats the control object 9 in a linear direction according to the pressure of the pressure chamber 32, and the servo valve 2 that compresses the pressure chamber 32. Air supply and exhaust; position detection sensor 4 (an example of a position detection unit) that detects the position of the control object 9; and controller 5 that inputs the detection position detected by the position detection sensor 4 to obtain a target The deviation between the positions, and a command voltage is output to the servo valve 2 based on the deviation. The servo cylinder system 1 is characterized in that the controller 5 has teaching Program 5a (an example of the teaching unit) and normal operation program 5b (especially S26 to S29, S31 in Figure 9 and an example of the voltage adjustment unit at startup). The control object 9 is moved from the predetermined origin position HP (after being lowered to the teaching predetermined movement position and then raised from the teaching predetermined movement position to the origin position HP), and it is detected that the control object 9 has left the predetermined position from the origin position HP Teaching position {the first teaching position X1, which is a predetermined distance (0.7 mm) from the origin position HP toward the lower side, and the second predetermined amount (3.3 mm) from the origin position HP toward the lower side ( The command voltage when the second teaching position X2} is 0.7 mm away from the prescribed movement position to the rising side) and used as the drive start command voltage (driving start command voltage Y1 for descent, driving start command voltage Y2 for ascent ) Stored: In the normal operation program 5b, when an operation instruction to move the control object 9 from the current position to the target position is input, the drive start command voltage (the drive start command voltage Y1 for falling or the drive for rising start is started) (Command voltage Y2) After entering the first operation instruction based on the deviation of the calculated first voltage command is calculated by adding a second command voltage, and outputs a second command voltage to the servo valve 2.

In the servo cylinder system 1 of the above embodiment, the controller 5 executes the instruction formula 5a to actually operate the components of the servo cylinder system 1 and outputs a command voltage to the servo valve 2 to move the control object 9 from the origin position HP. (After descending to the teaching prescribed movement position, it rises from the teaching prescribed moving position to the origin position HP). At this time, the controller 5 detects the teaching position 9 where the control object 9 is separated from the origin position HP by a predetermined amount {the first teaching position X1 that is separated from the origin position HP by a first predetermined amount (0.7 mm) toward the lower side. And a second predetermined amount (3.3mm) away from the origin position HP toward the lower side (moving from the teaching regulations The command voltage at the second teaching position X2} whose position is 0.7 mm away from the rising side) is stored as a drive start command voltage (driving start command voltage Y1 for falling or driving start command voltage Y2 for rising). Therefore, the drive start command voltage is a value at which the servo cylinder system 1 can surely start the cylinder 3 (begin to descend or start to rise).

When the controller 5 inputs an operation instruction to move the control object 9 from the current position to the target position, the controller 5 outputs a command voltage to the servo valve 2 based on the deviation between the detected position detected by the position detection sensor 4 and the target position. . At this time, based on S26 to S29 and S31 (refer to FIG. 9) of the normal operation program 5b, the controller 5 sets the driving start command voltage (driving start command voltage Y1 for falling or driving start for rising) stored by the teaching operation described above. The command voltage Y2) is added to the first command voltage calculated first based on the deviation after the operation instruction is input, thereby calculating a second command voltage and outputting the second command voltage to the servo valve 2. Since the second command voltage larger than the first command voltage is applied to the cylinder 3, when the second command voltage is output to the servo valve 2, the cylinder 3 is immediately started to move the control object 9 from the current position toward the target position. The cylinder 3 and the servo valve 2 require a large force at the time of starting, but it is easy to operate smoothly after starting. Therefore, after the cylinder 3 is started, the servo cylinder system 1 moves the control object 9 to the target position based on the command voltage output by the controller 5 based on the deviation between the detected position and the target position.

In this way, in the servo cylinder system 1 configured as described above, when an operation instruction is input, a second command voltage larger than the first command voltage calculated based on the deviation first based on the deviation is output to the servo valve 2 even if the servo cylinder is configured. The characteristics of the components such as the cylinder 3 and the servo valve 2 of the system 1 differ between products, Or it can degrade over a long period of time, and it is possible to start the cylinder 3 responsively (begin to descend or start to rise). Therefore, the servo cylinder system 1 configured as described above can improve the responsiveness according to the characteristics and deterioration state of the product, can uniformize the position control performance among the products, and can maintain the initial position control performance.

In addition, in the servo cylinder system 1 of the present embodiment, the teaching formula 5a sets the teaching position (the first or second teaching positions X1 and X2) to be generated based on the position of the control object 9 before moving to the origin position HP. The difference between the driving start command voltages (driving start command voltage Y1 for rising and driving start command voltage Y2 for rising) is small. Therefore, regardless of where the control object 9 stops at the start of the teaching operation, the difference between the driving start command voltages (driving start command voltage Y1 for falling or driving start command voltage Y2 for rising) detected by the teaching operation is small. Therefore, no matter where the position of the control object 9 is when the teaching operation is performed, when the control object 9 is moved to the target position, it is possible to output to the servo valve the first position calculated based on the deviation after inputting the operation instruction. A second command voltage having a large command voltage causes the cylinder 3 to start immediately (begins to descend or start to rise). Therefore, according to the servo cylinder system 1 of the present embodiment, the response can be improved without changing the control of the teaching operation and the normal operation according to the position of the control object 9.

In addition, in the servo cylinder system 1 of the present embodiment, the tutorial formula 5a includes a preparation unit (refer to S1 and S2 in FIG. 2), and the preparation unit outputs to the servo valve 2 before moving the control object 9 to the origin position HP. The voltage is commanded to move the control object 9 to the maximum extended position (lower limit position), which is the maximum extended (lowered) position. Therefore, since the servo cylinder system 1 has a sufficient distance for stable control during teaching operation, Compared with the case where the control object 9 is reached from a position other than the maximum extension position (lower limit position) to the origin position HP, the amount of overshoot can be reduced, so that the control object 9 can reach the origin position HP as quickly as possible. Thus, according to the servo cylinder system 1 of this embodiment, the control object 9 can reach the origin position HP with high accuracy in a short time.

Therefore, according to the servo cylinder system 1 of this embodiment, it is possible to provide the servo cylinder system 1 which can improve the responsiveness at the time of starting of the cylinder 3 and can achieve uniformity of position control performance and maintenance thereof.

The present invention is not limited to the above-mentioned embodiments, and can be applied to various applications.

(1) For example, in the above-described embodiment, the position detection unit is configured by the position detection sensor 4 that detects the position of the control object 9 from the position of the piston 33. However, the position detection unit may also detect the position of the output lever 34 or the pressure of the pressure chamber 32 to detect the position of the control object 9, and may also directly detect the position of the control object 9. In addition, the position detection unit may be configured to detect the position of the piston 33 of the cylinder 3, the pressure of the pressure chamber 32, and the position of the output lever 34 by a sensor, and output the detection result to the controller 5, which is detected by the controller 5. As a result, the position of the control object 9 is calculated.

(2) For example, in the above-mentioned embodiment, the compressed air supplied to the first and second pressure chambers 32a, 32b is controlled by one servo valve 2. However, each of the first operation port 31a and the second operation port 31b may be provided with one air supply and exhaust valve, and a servo valve may be formed by the pair of air supply and exhaust valves.

(3) For example, in the above-mentioned embodiment, the instruction formula 5a outputs a command voltage to the servo valve 2 to move the control object 9 to the lower limit position. Move to the origin position HP again, but it is also possible to output a command voltage to the servo valve 2 so that the control object 9 is at a position other than the lower limit position (for example, the upper limit position, a position slightly higher than the lower limit position (for example, 0.1 mm), etc.) After moving to the origin position.

In the above embodiment, the air cylinder 3 is arranged so that the output lever 34 projects downward. However, the air cylinder 3 may be configured so that the output lever 34 projects upward, and may also be configured so that the output lever 34 reciprocates in a horizontal direction.

In the above-mentioned embodiment, the driving start command voltage for falling and rising is detected and stored by one teaching operation, but the driving start command voltage for falling and the driving start command voltage for rising may be taught by different teaching operations. Detected and stored.

In the above embodiment, the origin position HP is set to the upper limit position, but the origin position HP can be set at any position as long as it is within the controllable range (for example, the lower limit position, the intermediate position between the upper limit position and the lower limit position, etc. ). In this case, as in the present embodiment, it is easy to control the position of the control object 9 during teaching operations.

Claims (3)

A servo cylinder system includes a cylinder that advances and retreats a control object in a linear direction according to the pressure of a pressure chamber; a servo valve that supplies and discharges compressed air to and from the pressure chamber; and a position detection unit that detects A position; and a controller that inputs a detection position detected by the position detection unit, obtains a deviation from a target position, and outputs a command voltage to the servo valve based on the deviation, wherein the controller has: A teaching unit that outputs a command voltage to the servo valve so that the control object moves from a predetermined origin position, and detects a command voltage when the control object leaves a predetermined amount of teaching position from the origin position, and It is stored as a drive start command voltage; and a voltage adjustment unit at start-up, when an operation instruction to move the control object from the current position to a target position is input, after the drive start command voltage and the operation instruction are input, Firstly calculate the first command voltage calculated based on the above deviation A second voltage command and the second command voltage to the servo valve output. The servo cylinder system according to item 1 of the scope of patent application, wherein the teaching unit sets the teaching position to a difference in the drive start command voltage generated according to a position of the control object before moving to the origin position. Small range. The servo cylinder system according to item 1 or 2 of the patent application scope, wherein the teaching unit includes a preparation unit, and the preparation unit outputs a command voltage to the servo valve before moving the control object to the origin position, so that The control object is moved to a maximum extension position that is maximally extended toward the opposite side of the cylinder.