Air cylinder control system and related pneumatic equipment

Abstract

The utility model discloses an air cylinder control system and related pneumatic equipment. The cylinder control system comprises at least one cylinder; the high-frequency valve and the quick response switch valve are connected with the air cylinder and used for achieving stretching or retracting movement of an air cylinder piston; the position sensor is arranged on the air cylinder and used for feeding back an air cylinder displacement signal to the controller; the controller is electrically connected with the high-frequency valve and the quick response switch valve, the flow of gas flowing into the two cavities of the air cylinders is controlled by adjusting the opening and closing time of the high-frequency valve, then the speed and position control over the air cylinders is achieved, meanwhile, the controller can be connected with the multiple air cylinders, and cooperative action of the multiple air cylinders can be achieved. According to the utility model, the high-frequency valve is introduced into the cylinder control system, so that the cylinder control system has the advantages of high control frequency, high-speed response, high repetition precision and low price, the high-frequency valve is controlled by the controller, the position and the speed of the cylinder can be conveniently and accurately controlled, and meanwhile, the overall cost of the cylinder control system is also reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of pneumatic control, in particular to a cylinder control system and related pneumatic equipment. Background Art

[0002] In the current industrial automation field, motion control is often achieved by using cylinders, electric cylinders or multi-cylinder synchronous motions of various specifications and characteristics. Today's automated motion control is developing rapidly towards intelligence, and the requirements for precise position control and precise motion speed control are becoming increasingly higher.

[0003] Although electric cylinders can meet the requirements of precise control of position and movement speed to a certain extent, their high price and high requirements for the working environment will greatly increase the investment cost. If a pneumatic cylinder is used as a power drive device, a high-precision proportional flow valve is usually used to control the position and movement speed, but the high-precision proportional flow valve is expensive and cannot intuitively set and control the speed. Utility Model Content

[0004] In view of the above problems, the present utility model is proposed to provide a cylinder control system and related pneumatic equipment that overcome the above problems or at least partially solve the above problems.

[0005] In a first aspect, an embodiment of the utility model provides a cylinder control system, comprising:

[0006] at least one cylinder, a controller, a first high frequency valve connected to the cylinder, a second high frequency valve, a first response switch, and a second fast response switch valve;

[0007] The controller is electrically connected to the first high-frequency valve and the second high-frequency valve respectively;

[0008] One end of the first high-frequency valve is connected to the gas source, and the other end is connected to the rodless chamber of the cylinder;

[0009] The first fast-response switch valve is electrically connected to the controller and communicates with the rodless chamber of the cylinder;

[0010] One end of the second high-frequency valve is connected to the gas source, and the other end is connected to the rod chamber of the cylinder;

[0011] The second fast-response switch valve is electrically connected to the controller and communicates with the rod chamber of the cylinder;

[0012] The controller is used to send control signals to the first high-frequency valve, the second high-frequency valve, the first fast-response switching valve and the second fast-response switching valve according to the feedback displacement signal of the piston in the cylinder, so as to control the second fast-response switching valve to open when the first high-frequency valve is opened, and the first fast-response switching valve and the second high-frequency valve to close; and the first fast-response switching valve to open when the second high-frequency valve is opened, and the second fast-response switching valve and the first high-frequency valve to close.

[0013] In one embodiment, the above cylinder control system further includes: a displacement sensor;

[0014] The displacement sensor is arranged on the cylinder, and is used for collecting the displacement signal of the piston in the cylinder, and transmitting the collected displacement signal to the controller.

[0015] In one embodiment, the above-mentioned cylinder control system also includes: a controller, which is specifically used to calculate the real-time position and speed of the piston rod based on the displacement signal collected by the displacement sensor, and according to the real-time position and speed of the piston rod, issue a control signal of the DUTY ratio when the first high-frequency valve or the second high-frequency valve is opened, and a control signal of opening or closing the first fast-response switch valve and the second fast-response switch valve.

[0016] The controller is also used to determine, based on the displacement signal collected by the displacement sensor, that when the piston reaches a preset target position, issue a control signal to close the first high-frequency valve, the second high-frequency valve, the first fast-response switch valve, and the second fast-response switch valve.

[0017] In one embodiment, the above-mentioned cylinder control system further includes: a magnetic ring is arranged on the piston rod of the cylinder, the displacement sensor is arranged on the outer wall of the cylinder, and the displacement signal of the piston is obtained by sensing the magnetic ring.

[0018] In one embodiment, the cylinder control system further includes: a muffler;

[0019] The muffler is connected to the first fast-response switching valve and / or the second fast-response switching valve.

[0020] In one embodiment, the cylinder control system further includes: the first high-frequency valve or the second high-frequency valve is connected to the same air source.

[0021] In one embodiment, the above cylinder control system further includes: when there are multiple cylinders, the multiple cylinders are connected to the same controller.

[0022] In one embodiment, in the above cylinder control system, the operating frequency of the first high-frequency valve and the second high-frequency valve is greater than or equal to 100 Hz.

[0023] In a second aspect, an embodiment of the utility model provides a pneumatic device, which includes at least one cylinder control system as described in any one of the first aspects.

[0024] The beneficial effects of the above technical solution provided by the embodiment of the utility model include at least:

[0025] The cylinder control system provided by the embodiment of the utility model introduces high-frequency valves into the cylinder control system. As high-frequency valves are becoming more and more mature and have high control frequency, can achieve high-speed response, and have high repetition accuracy, the controller can conveniently achieve precise control of the cylinder position and speed through the control of the first high-frequency valve, the second high-frequency valve, the first fast-response switch valve, and the second fast-response switch valve according to the displacement signal of the piston in the cylinder fed back by the controller; as high-frequency valves are inexpensive, the overall cost of the cylinder control system is also reduced. In the scenario of multi-cylinder actuation, the controller can be used to control multiple cylinders to achieve precise synchronous linkage.

[0026] Other features and advantages of the utility model will be described in the subsequent description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other advantages of the utility model can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings.

[0027] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 A schematic diagram of the structure of a cylinder control system provided by an embodiment of the utility model;

[0030] Figure 2 A flow chart of bidirectional real-time control of cylinder position and speed provided by an embodiment of the utility model;

[0031] Description of reference numerals:

[0032] 1-cylinder; 2-position sensor; 3-controller; 4-first high-frequency valve; 5-second high-frequency valve; 6-first fast-response switch valve; 7-second fast-response switch valve; 8-muffler; 9-gas source. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0034] The utility model embodiment provides a cylinder control system, referring to Figure 1 As shown, the cylinder control system includes: at least one cylinder 1, a controller 3, a first high-frequency valve 4 connected to the cylinder 1, a second high-frequency valve 5, a first fast-response switch valve 6, and a second fast-response switch valve 7. Among them:

[0035] The controller 3 is electrically connected to the first high-frequency valve 4 and the second high-frequency valve 5 respectively; wherein one end of the first high-frequency valve 4 is connected to the air source 9, and the other end is connected to the rodless chamber of the cylinder 1;

[0036] The first fast response switch valve 6 is electrically connected to the controller 3 and communicated with the rodless chamber of the cylinder 1; one end of the second high frequency valve 5 is communicated with the air source 9, and the other end is communicated with the rod chamber of the cylinder 1;

[0037] The second fast-response switch valve 7 is electrically connected to the controller 3 , and communicates with the rod chamber of the cylinder 1 .

[0038] The controller 3 is used to send control signals to the first high-frequency valve 4, the second high-frequency valve 5, the first quick-response switch valve 6 and the second quick-response switch valve 7 according to the feedback displacement signal of the piston in the cylinder 1, so as to control the first high-frequency valve 4 to open and the second quick-response switch valve 7 to open, and the first quick-response switch valve 6 and the second high-frequency valve 5 to close; and when the second high-frequency valve 5 is opened, the first quick-response switch valve 6 is opened, and the second quick-response switch valve 7 and the first high-frequency valve 4 are closed.

[0039] In the embodiment of the utility model, the response speed of the first fast response switch valve 6 needs to match the speed of the switch of the first high frequency valve 4, and similarly, the response speed of the second fast response switch valve 7 also needs to match the speed of the switch of the second high frequency valve 5. In general, the first fast response switch valve 6 matches the opening or closing action of the first high frequency valve 4, and the second fast response switch valve 7 matches the opening or closing action of the second high frequency valve 5, which can ensure the stability of the cylinder actuation.

[0040] exist Figure 1 In the cylinder control system shown in FIG. 1 , the controller 3 controls the actuation of the cylinder 1 through the first high-frequency valve 4, the second high-frequency valve 5, the first fast-response switch valve 6, and the second fast-response switch valve 7 and other electromagnetic valves. Those skilled in the art can Figure 1It can be easily imagined from the structural diagram that when the same controller controls multiple cylinders (greater than or equal to 2), multiple cylinders use their own adaptive high-frequency valves and fast-response switch valves respectively. Figure 1 The structure is similar to that in which the high-frequency valves and the fast-response switch valves adapted to the multiple cylinders are controlled by the controller, that is, the controller is electrically connected to the high-frequency valves and the fast-response switch valves adapted to the multiple cylinders, respectively. Figure 1 The controller 3 shown is an example of controlling one cylinder 1 , but the present invention is applicable to scenarios where multiple cylinders are actuated.

[0041] In the scenario of multi-cylinder actuation, the controller can be used to make it possible for multiple cylinders to be precisely synchronized.

[0042] The above-mentioned cylinder control system provided by the embodiment of the utility model introduces high-frequency valves into the cylinder control system. As high-frequency valves are becoming more and more mature and have the advantages of high control frequency, high-speed response, high repetition accuracy and low price, the controller controls the first high-frequency valve, the second high-frequency valve, the first fast-response switch valve and the second fast-response switch valve according to the feedback displacement signal of the piston in the cylinder, thereby conveniently realizing precise control of the cylinder position, speed, etc., and also reducing the overall cost of the cylinder control system.

[0043] In one embodiment, the first high-frequency valve 4 and the second high-frequency valve 5 can be connected to the same gas source 9 .

[0044] In some embodiments, reference Figure 1 As shown, the cylinder control system further includes at least one displacement sensor 2 ; the displacement sensor 2 is disposed on the cylinder 1 , and is used to collect a displacement signal of a piston in the cylinder 1 , and transmit the collected displacement signal to the controller 3 .

[0045] During the movement of the cylinder, the displacement sensor 2 can collect the position information of the piston, that is, the displacement signal, and the collected displacement signal is fed back to the controller 3;

[0046] The controller 3 simultaneously receives the position command and the speed command, as well as the feedback displacement signal of the piston, calculates the real-time speed and position of the piston rod in the cylinder 1, and controls the opening and closing time (duty ratio) of the first high-frequency valve 4 and the second high-frequency valve 5 through the built-in algorithm to control the flow rate flowing into the two chambers (rod chamber and rodless chamber) of the cylinder 1, thereby realizing speed control, and controls the piston rod to move forward by opening the first high-frequency valve 4 and the second fast-response switch valve 7, and closing the second high-frequency valve 5 and the first fast-response switch valve 6. Figure 1The right side movement shown in the figure (the rodless chamber becomes larger and the rod chamber becomes smaller) controls the piston rod to move to the right side by opening the second high-frequency valve 5 and the first fast-response switch valve 6 and closing the first high-frequency valve 4 and the second fast-response switch valve 7. Figure 1 The left side movement shown (rod cavity becomes larger, rodless cavity becomes smaller) realizes the control of the position of the piston rod, thus realizing the dual control of speed and position.

[0047] In one embodiment, a magnetic ring is provided on the piston rod of the cylinder 1 .

[0048] The displacement sensor 2 is arranged on the upper side of the outer wall of the cylinder, and collects the displacement signal of the piston rod in the cylinder 1 through magnetic ring induction, and then feeds back the collected displacement signal to the controller 3.

[0049] In one embodiment, referring to Figure 1 As shown in the figure, the specific implementation process of the system controlling the high-frequency valve action is as follows:

[0050] The controller 3 receives the speed command and the position command, calculates the specific opening or closing time of each high-frequency valve, and controls the high-frequency valve action time through the high-frequency valve control unit to adjust the gas volume in the two chambers of the cylinder. The relationship between the high-frequency valve actuation and the cylinder movement can be, for example:

[0051] When the first high-frequency valve 4 is opened and the second fast-response switch valve 7 is opened, and the second high-frequency valve 5 is closed and the first fast-response switch valve 6 is closed, the rod chamber of the cylinder 1 is exhausted and the piston rod extends;

[0052] When the second high-frequency valve 5 is opened and the first fast-response switch valve 6 is opened, the first high-frequency valve 4 is closed and the second fast-response switch valve 7 is closed, the rodless chamber of the cylinder 1 is exhausted and the piston rod retracts.

[0053] The controller 3 can use existing control algorithms to calculate the piston position and speed, such as PID control algorithms and anti-disturbance algorithms. Figure 2 The control flow shown is briefly described as follows:

[0054] (1) The controller 3 receives a position command and a speed command, and calculates a position command value corresponding to the position command and a speed command value corresponding to the speed command.

[0055] (2) The controller 3 calculates the real-time position value and real-time speed value of the piston rod of the current cylinder 1 according to the displacement feedback signal of the displacement sensor 2.

[0056] (3) The controller 3 determines the deviation between the position command value indicated by the current command and the current real-time position value of the piston. For example, assuming that the position deviation value is the value obtained by subtracting the current real-time position value from the current position command value, a positive number indicates that the piston rod is required to extend outward, and a negative number indicates that the piston rod is required to retract inward.

[0057] If the position deviation value is equal to 0, the first high-frequency valve 4, the second high-frequency valve 5, the first fast-response switch valve 6, and the second fast-response switch valve 7 are all closed, and the piston rod in the cylinder 1 maintains the current position;

[0058] If the position deviation value is not equal to 0, there are two situations: when the position deviation value is greater than 0, that is, the piston rod is required to extend outward, then the first high-frequency valve 4 and the second fast-response switch valve 7 are both opened, the second high-frequency valve 5 and the first fast-response switch valve 6 are both closed, and the rod chamber of cylinder 1 is exhausted; when the position deviation value is less than 0, that is, the piston rod is required to retract inward, then the second high-frequency valve 5 and the first fast-response switch valve 6 are both opened, the first high-frequency valve 4 and the second fast-response switch valve 7 are both closed, and the rod chamber of cylinder 1 is inlet. In order to avoid large oscillations caused by the piston rod in cylinder 1 moving in a smaller position deviation value range, that is, oscillations near the position deviation 0 point, the position dead zone can be set by the controller 3 control parameters, that is, when the position deviation value is within the dead zone, the first high-frequency valve 4, the second high-frequency valve 5, the first fast-response switch valve 6, and the second fast-response switch valve 7 are all closed.

[0059] (4) Under the precondition that the position deviation value is not equal to 0, the controller 3 determines the deviation value between the speed command value indicated by the instruction and the current real-time speed value of the piston.

[0060] (5) If the speed deviation value is equal to 0, the first high-frequency valve 4 or the second high-frequency valve 5 maintains the current driving duty ratio; if the speed deviation value is not equal to 0, the control algorithm built into the controller 3 will be triggered to perform control calculations, adjust the driving duty ratio of the first high-frequency valve 4 or the second high-frequency valve 5, and then realize the extension or contraction movement of the piston rod in the cylinder 1 according to the set speed command value.

[0061] Thus, by controlling the high-frequency valve group (the first high-frequency valve 4, the second high-frequency valve 5) and the fast-response switch valve group (the first fast-response switch valve 6 and the second fast-response switch valve 7) as described above, the dual closed-loop real-time control of position control and speed control can be achieved. By adjusting the speed command and the position command, the piston rod in the cylinder 1 can be made to follow the predetermined action curve.

[0062] The actuation frequency, dead zone, etc. of the first high-frequency valve 4 and the second high-frequency valve 5 can be set by the controller 3 to adapt to different high-frequency valves and control response speed requirements.

[0063] In some embodiments, reference Figure 1 As shown, the control system may further include a muffler device 8. The muffler 8 is connected to the first fast response switch valve 6 and / or the second fast response switch valve 7. It is used to reduce the noise generated when the first fast response switch valve 6 and / or the second fast response switch valve 7 is actuated, thereby reducing vibration, maintaining the gas path, and making the control system run stably.

[0064] In the above embodiment, the cylinder control system provided by the utility model can calculate the control amount of the high-frequency valve in real time by comparing the speed command with the real-time speed and the set position command with the real-time position, thereby realizing real-time control of the bidirectional speed and position of the low-friction cylinder, providing a new solution for using high-frequency valves to perform real-time control of the speed and position of the cylinder, and providing support for realizing scenarios of coordinated action of multiple cylinders.

[0065] In some embodiments, the operating frequency of the first high-frequency valve 4 and the second high-frequency valve 5 in the cylinder control system is greater than or equal to 100 Hz.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A cylinder control system, characterized in that: include: At least one cylinder, a controller, a first high-frequency valve connected to the cylinder, a second high-frequency valve, a first fast-response switch valve, and a second fast-response switch valve; The controller is electrically connected to the first high-frequency valve and the second high-frequency valve respectively; One end of the first high-frequency valve is connected to the gas source, and the other end is connected to the rodless chamber of the cylinder; The first fast-response switch valve is electrically connected to the controller and communicates with the rodless chamber of the cylinder; One end of the second high-frequency valve is connected to the gas source, and the other end is connected to the rod chamber of the cylinder; The second fast-response switch valve is electrically connected to the controller and communicates with the rod chamber of the cylinder; The controller is used to send control signals to the first high-frequency valve, the second high-frequency valve, the first fast-response switching valve and the second fast-response switching valve according to the feedback displacement signal of the piston in the cylinder, so as to control the second fast-response switching valve to open when the first high-frequency valve is opened, and the first fast-response switching valve and the second high-frequency valve to close; and the first fast-response switching valve to open when the second high-frequency valve is opened, and the second fast-response switching valve and the first high-frequency valve to close.

2. The cylinder control system according to claim 1, characterized in that: Also includes: Displacement sensor; The displacement sensor is arranged on the cylinder, and is used for collecting the displacement signal of the piston in the cylinder, and transmitting the collected displacement signal to the controller.

3. The cylinder control system according to claim 2, characterized in that: The controller is specifically used to calculate the real-time position and speed of the piston rod according to the displacement signal collected by the displacement sensor, and to issue a control signal of the DUTY ratio when the first high-frequency valve or the second high-frequency valve is opened, as well as a control signal of the first fast-response switch valve and the second fast-response switch valve being opened or closed according to the real-time position and speed of the piston rod.

4. The cylinder control system according to claim 3, characterized in that: The controller is also used to determine, based on the displacement signal collected by the displacement sensor, that when the piston reaches a preset target position, issue a control signal to close the first high-frequency valve, the second high-frequency valve, the first fast-response switch valve, and the second fast-response switch valve.

5. The cylinder control system according to claim 2, characterized in that: A magnetic ring is arranged on the piston rod of the cylinder, and the displacement sensor is arranged on the outer wall of the cylinder. The displacement signal of the piston is obtained by sensing the magnetic ring.

6. The cylinder control system according to claim 2, characterized in that: Also includes: Muffler; The muffler is connected to the first fast-response switching valve and / or the second fast-response switching valve.

7. The cylinder control system according to any one of claims 1 to 6, characterized in that: The first high-frequency valve or the second high-frequency valve is connected to the same gas source.

8. The cylinder control system according to any one of claims 1 to 6, characterized in that: When there are multiple cylinders, the multiple cylinders are connected to the same controller.

9. The cylinder control system according to any one of claims 1 to 6, characterized in that: The operating frequency of the first high-frequency valve and the second high-frequency valve is greater than or equal to 100 Hz.

10. A pneumatic device, characterized in that: The pneumatic device comprises at least one cylinder control system according to any one of claims 1-9.

Images