A control method for adjusting the jet trajectory

Abstract

The present invention provides a control method for adjusting the jet trajectory, including: acquiring an image of the jet trajectory when the Taylor cone angle of the metal nozzle is in a stable state, and processing the image to obtain a first offset angle of the jet trajectory; controlling the voltage on the electrode plate located beside the jet trajectory according to the first offset angle to coarsely adjust the offset angle of the jet trajectory; acquiring a second offset angle of the jet trajectory after preliminary adjustment again; and controlling the horizontal position of the equipotential ring located below the metal nozzle according to the second offset angle to finely adjust the offset angle of the jet trajectory. This method coarsely adjusts the offset angle of the jet trajectory by setting an electrode plate beside the jet trajectory and using the repulsive force generated by the electrode plate, and then finely adjusts the offset angle of the jet trajectory by adjusting the horizontal position of the equipotential ring, so as to make the jet trajectory as vertical as possible and avoid the problem of uneven microspheres / microcapsules formed by droplets.

Description

Technical Field

[0001] The present invention relates to the technical field of control and regulation systems, and particularly to a control method for adjusting a jet trajectory. Background Art

[0002] The method for preparing microspheres / microcapsules by high-voltage electrostatic spraying uses a high-voltage electrostatic generating device to charge the ejected droplets, and is used for the preparation of microspheres / microcapsules. The method for preparing microspheres / microcapsules by high-voltage electrostatic spraying has been widely applied in many fields such as drug delivery, food industry, and materials science due to its unique encapsulation performance and controllable microsphere / microcapsule size.

[0003] The general technological process of the method for preparing microspheres / microcapsules by high-voltage electrostatic spraying is as follows: the positive electrode of a high-voltage generator is connected to a metal nozzle, and the negative electrode is connected to an equipotential ring. The metal nozzle is suspended at a certain distance directly above the equipotential ring. When preparing, the power supply is turned on, and a high-voltage electric field is generated between the two electrodes. When an injection pump pushes out the solution at a constant speed, the electric field force overcomes the inherent viscous force and surface tension of the solution, causing it to be ejected as microspheres with a certain particle size into the solidifying liquid and quickly solidify. When using coaxial double nozzles, the metal nozzle is connected to two different solutions, and under the action of the electric field force, microsphere capsules with a double-layer structure will be formed.

[0004] The microspheres / microcapsules prepared by the high-voltage electrostatic spraying method have shown great application potential in many fields due to their high efficiency and controllability. However, in the actual preparation process, the deviation of the jet trajectory often causes the prepared microspheres / microcapsules to change from a perfect spherical shape to an ellipsoidal shape or other irregular shapes, especially resulting in uneven thickness of the capsule shell of the microcapsule, which limits its application. Summary of the Invention

[0005] In view of the above defects of the prior art, the present invention provides a control method for adjusting a jet trajectory to improve the perpendicularity of the jet trajectory and avoid the technical problem of jet trajectory deviation.

[0006] To achieve the above object and other related objects, the present invention provides a control method for adjusting a jet trajectory, including: acquiring an image of the jet trajectory when the Taylor cone angle of the metal nozzle is in a stable state, and processing the image to obtain the first deviation angle of the jet trajectory; according to the first deviation angle, controlling the voltage on the electrode plate located beside the jet trajectory to roughly adjust the deviation angle of the jet trajectory; acquiring the second deviation angle of the jet trajectory after preliminary adjustment again; according to the second deviation angle, controlling the horizontal position of the equipotential ring located below the metal nozzle to finely adjust the deviation angle of the jet trajectory.

[0007] In an embodiment of the present invention, an image of the jet trajectory when the Taylor cone angle of the metal nozzle is in a stable state is acquired, and the image is processed to obtain a first deviation angle of the jet trajectory, including: acquiring images of the jet trajectory captured by a first camera and a second camera, wherein the central axes of the first camera and the second camera are both in the horizontal plane and perpendicular to each other; processing the image captured by the first camera to obtain the deviation angle of the jet trajectory in a first direction; processing the image captured by the second camera to obtain the deviation angle of the jet trajectory in a second direction; and calculating the first deviation angle according to the deviation angle of the jet trajectory in the first direction and the deviation angle in the second direction.

[0008] In an embodiment of the present invention, the metal nozzle and the equipotential ring are respectively connected to the positive electrode and the negative electrode of a high-voltage generator; the high-voltage generator is further provided with a second positive electrode, and the electrode plate is connected to the second positive electrode.

[0009] In an embodiment of the present invention, there is one electrode plate; controlling the voltage on the electrode plate located beside the jet trajectory according to the first deviation angle includes: moving the electrode plate to the side where the jet trajectory deviates according to the first deviation angle; and adjusting the output voltage of the second positive electrode of the high-voltage generator according to the first deviation angle.

[0010] In an embodiment of the present invention, there are multiple electrode plates, and the multiple electrode plates are evenly spaced along the circumferential direction. Each electrode plate is respectively connected to the second positive electrode of the high-voltage generator through a switch; controlling the voltage on the electrode plate located beside the jet trajectory according to the first deviation angle includes: determining the electrode plates among the multiple electrode plates that are located on the side where the jet trajectory deviates according to the first deviation angle; turning on the switch corresponding to the electrode plate located on the side where the jet trajectory deviates; and adjusting the output voltage of the second positive electrode of the high-voltage generator according to the first deviation angle.

[0011] In an embodiment of the present invention, adjusting the output voltage of the second positive electrode of the high-voltage generator according to the first deviation angle includes: obtaining a first prediction factor according to the first deviation angle and a preset rough adjustment target angle of the jet trajectory; and using a first PID controller based on a first BP neural network to control the output voltage of the second positive electrode of the high-voltage generator, wherein the input quantities of the first BP neural network include the rough adjustment target angle of the jet trajectory, the first prediction factor, and the control signal output by the first PID controller.

[0012] In an embodiment of the present invention, in the step of re-acquiring the second offset angle of the jet trajectory after preliminary adjustment, the offset angle of the jet trajectory in the first direction and the offset angle in the second direction are used as the second offset angle.

[0013] In an embodiment of the present invention, according to the second offset angle, controlling the horizontal position of the equipotential ring located below the metal nozzle includes: controlling the movement of the equipotential ring in the first direction according to the offset angle of the jet trajectory in the first direction and a preset fine-tuning target angle of the jet trajectory in the first direction; controlling the movement of the equipotential ring in the second direction according to the offset angle of the jet trajectory in the second direction and a preset fine-tuning target angle of the jet trajectory in the second direction.

[0014] In an embodiment of the present invention, controlling the movement of the equipotential ring in the first direction according to the offset angle of the jet trajectory in the first direction and a preset fine-tuning target angle of the jet trajectory in the first direction includes: obtaining a second prediction factor according to the offset angle of the jet trajectory in the first direction and a preset fine-tuning target angle of the jet trajectory in the first direction; using a second PID controller based on a second BP neural network to control the output instruction of the motor controller, and the motor controller controls the movement of the equipotential ring in the first direction through a motor, wherein the input quantity of the second BP neural network includes the fine-tuning target angle of the jet trajectory in the first direction, the second prediction factor, and the control signal output by the second PID controller.

[0015] Advantages of the present invention: A control method for adjusting the jet trajectory proposed by the present invention. In this method, an electrode plate is arranged beside the jet trajectory, and the repulsive force generated by the electrode plate is used to roughly adjust the offset angle of the jet trajectory. Then, by adjusting the horizontal position of the equipotential ring, the fine adjustment of the offset angle of the jet trajectory is realized, so that the jet trajectory is as vertical as possible, ensuring that the spraying direction of the liquid droplets is basically consistent with the gravity direction, and further avoiding the problem of non-uniform microspheres / microcapsules formed by the liquid droplets. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a flowchart of the control method provided by an embodiment of the present invention;

[0018] Figure 2Schematic diagram of the jet trajectory control system provided by an embodiment of the present invention;

[0019] Figure 3 Detailed flowchart of step S100 provided by an embodiment of the present invention;

[0020] Figure 4 Schematic diagrams of various angles provided by an embodiment of the present invention;

[0021] Figure 5 Flowchart of the first control method for the voltage of the electrode plate provided by an embodiment of the present invention;

[0022] Figure 6 Flowchart of the second control method for the voltage of the electrode plate provided by an embodiment of the present invention;

[0023] Figure 7 Detailed flowchart of step S240 provided by an embodiment of the present invention;

[0024] Figure 8 Schematic diagram of the first PID controller based on the first BP neural network provided by an embodiment of the present invention;

[0025] Figure 9 Flowchart of the control method for the horizontal position of the equipotential ring provided by an embodiment of the present invention;

[0026] Figure 10 Detailed flowchart of step S410 provided by an embodiment of the present invention;

[0027] Figure 11 Schematic diagram of the second PID controller based on the second BP neural network provided by an embodiment of the present invention;

[0028] Figure 12 Schematic diagram of the third PID controller based on the third BP neural network provided by an embodiment of the present invention.

[0029] Explanation of reference numerals: 10, metal spray head; 11, Taylor cone angle; 20, first camera; 30, second camera; 40, electrode plate; 50, equipotential ring; 60, high-voltage generator. Detailed implementation manners

[0030] The following describes the implementation modes of the present invention through specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Except for the specific methods, devices, and materials used in the embodiments, according to the knowledge of those skilled in the art in the present technical field and the description of the present invention, any methods, devices, and materials similar to or equivalent to the methods, devices, and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0031] It should be understood that the terms used in the embodiments of the present invention are for the purpose of describing specific specific implementation manners, rather than for limiting the protection scope of the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art of this technical field.

[0032] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limited conditions under which the present invention can be implemented. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. Moreover, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and ratios of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0033] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In some of these embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0034] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions, and operations that the methods and computer program products according to various embodiments disclosed in the present invention may achieve. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a portion of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in an order different from that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as combinations of blocks in the block diagram and / or flowchart, may be implemented by a dedicated hardware-based system that performs the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions.

[0035] When preparing microspheres / microcapsules using the high-voltage electrostatic spraying method, in addition to the stability of the Taylor cone angle affecting the uniformity of the microspheres / microcapsules, if the verticality of the jet trajectory below the Taylor cone is insufficient, it will also affect the uniformity of the microspheres / microcapsules.

[0036] In practical applications, there are many reasons that can cause the deviation of the jet trajectory, such as the deviation of the positions of the metal nozzle and the equipotential ring, uneven electric field, properties of the liquid, and external interference. When the jet trajectory deviates, the deviation of the jet trajectory will cause the liquid droplets to be affected by a lateral force during the formation process, changing the shape of the liquid droplets from a perfect spherical shape to an ellipsoidal shape or other irregular shapes; it will also cause the uneven distribution of the liquid droplets in space. For example, the liquid droplets may gather in the direction of the deviation of the jet, forming an uneven group of liquid droplets, and this uneven distribution will affect the uniformity of the microspheres / microcapsules formed by the liquid droplets. Therefore, it is necessary to control the jet trajectory to maintain its verticality as much as possible, that is, the jet trajectory is vertically downward, so as to avoid the unevenness of the microspheres / microcapsules formed by the liquid droplets.

[0037] Please refer to Figure 1 , Figure 1 A control method for adjusting the jet trajectory provided in an embodiment of the present invention includes steps S100 to S400. For the convenience of clearly understanding these steps, please refer to Figure 2 the structural schematic diagram to understand the positional relationship of each component. Figure 2 In [the figure], only the components involved in the present invention are schematically shown, and some other components are omitted.

[0038] Step S100: Obtain an image of the jet trajectory when the Taylor cone angle 11 of the metal nozzle 10 is in a stable state, and process the image to obtain the first offset angle of the jet trajectory. To adjust the offset of the jet trajectory, it is first necessary to obtain the offset angle of the current jet trajectory. In this embodiment, conventional image recognition and processing techniques are used to obtain the first offset angle of the jet trajectory. The first offset angle is the offset angle of the jet trajectory without any adjustment. In this step, the reason for obtaining the image of the jet trajectory when the Taylor cone angle 11 is in a stable state is that only when the Taylor cone angle 11 is in a stable state, its jet trajectory will be relatively stable, and then it can be adjusted.

[0039] Please refer to Figure 3 , in a specific embodiment of the present invention, step S100 may include steps S101 to S104, for example.

[0040] Step S101: Obtain images of the jet trajectory captured by the first camera 20 and the second camera 30. Among them, the central axes of the first camera 20 and the second camera 30 are both located in the horizontal plane and perpendicular to each other. Since the jet trajectory can deviate in any direction in the horizontal plane from top to bottom, two orthogonal cameras are set to capture images of the jet trajectory from two angles respectively. It can be understood that it is also feasible that the central axes of the first camera 20 and the second camera 30 are not perpendicular, but it is not conducive to subsequent calculations.

[0041] Step S102: Process the image captured by the first camera 20 to obtain the offset angle of the jet trajectory along the first direction. Step S103: Process the image captured by the second camera 30 to obtain the offset angle of the jet trajectory along the second direction. For the convenience of calculation, a coordinate system is usually established. In these two steps, the central axis of the second camera 30 is used as the X-axis (i.e., the first direction), and the central axis of the first camera 20 is used as the Y-axis (i.e., the second direction). In this way, when processing the image captured by the first camera 20, the obtained is the offset angle of the jet trajectory along the X-axis. Similarly, when processing the image captured by the second camera 30, the obtained is the offset angle of the jet trajectory along the Y-axis.

[0042] Step S104: Calculate the first offset angle according to the offset angle of the jet trajectory along the first direction and the offset angle along the second direction. Please refer to Figure 4, for example, denote the deflection angle of the jet trajectory along the first direction as θ1 and the deflection angle along the second direction as θ2. In this step, it is necessary to first calculate the angle θ3 between the jet trajectory and the positive direction of the X-axis in the XOY plane based on θ1 and θ2, and then calculate the angle θ4 between the jet trajectory and the Z-axis. The first deflection angle can be denoted as (θ3, θ4), which is calculated based on θ1 and θ2. In subsequent steps, the position of the electrode plate 40 can be adjusted according to θ3, and θ4 is y_θ(k) in the following text. The following text also mentions the second deflection angle, which does not need to be calculated and can be directly denoted as (θ1, θ2).

[0043] Step S200: According to the first deflection angle, control the voltage on the electrode plate 40 located beside the jet trajectory to roughly adjust the deflection angle of the jet trajectory. In this embodiment, a repulsive force is generated by controlling the electrode plate 40 beside the jet trajectory, thereby realizing the rough adjustment of the deflection angle of the jet trajectory.

[0044] In a specific embodiment of the present invention, the metal nozzle 10 and the equipotential ring 50 are respectively connected to the positive and negative electrodes of the high-voltage generator 60. At the same time, the electrode plate 40 is also connected to the positive electrode, and it has the same polarity as the metal nozzle 10. At this time, the electrode plate 40 will generate a repulsive force on the liquid droplets Electrode plate 40 Metal nozzle 10 Electrode plate 40.

[0045] In a specific embodiment of the present invention, the high-voltage generator 60 is also provided with a second positive electrode ( Figure 2 Only the connection relationship between the metal nozzle 10 and the high-voltage generator 60 is schematically shown in the figure, and the connection relationship between the electrode plate 40 and the high-voltage generator 60 is omitted), and the electrode plate 40 is connected to the second positive electrode so that the electrode plate 40 generates a repulsive force on the liquid droplets, that is, the jet trajectory will deflect away from the electrode plate 40 under the action of the electrode plate 40.

[0046] Please refer to Figure 5 , in a specific embodiment of the present invention, only one electrode plate 40 is provided. Controlling the voltage on the electrode plate 40 located beside the jet trajectory according to the first deflection angle includes: S210: According to the first deflection angle, control the electrode plate 40 to move to the offset side of the jet trajectory; S240: According to the first deflection angle, adjust the output voltage of the second positive electrode of the high-voltage generator 60. In order to control the jet trajectory to be as vertical as possible, in step S210, the electrode plate 40 is moved to the offset side of the jet trajectory, so that under the action of the repulsive force of the electrode plate 40, the deflection angle of the jet trajectory will decrease. The higher the voltage on the electrode plate 40, the greater the repulsive force. By controlling the output voltage of the second positive electrode of the high-voltage generator 60, the deflection angle can be adjusted more accurately.

[0047] In step S210, the electrode plate 40 is moved to one side of the jet trajectory. Specifically, the movement is as follows: directly according to θ3 of the first offset angle, the electrode plate 40 is moved to a position with an angle of θ3 with respect to the positive direction of the X-axis.

[0048] Please refer to Figure 6 , in a specific embodiment of the present invention, multiple electrode plates 40 are provided. The multiple electrode plates 40 are evenly spaced along the circumferential direction. Each electrode plate 40 is respectively connected to the second positive electrode of the high-voltage generator 60 through a switch. Controlling the voltage on the electrode plate 40 located beside the jet trajectory according to the first offset angle includes: S220, determining the electrode plate 40 among the multiple electrode plates 40 that is located on the offset side of the jet trajectory according to the first offset angle; S230, turning on the switch corresponding to the electrode plate 40 located on the offset side of the jet trajectory; S240, adjusting the output voltage of the second positive electrode of the high-voltage generator 60 according to the first offset angle.

[0049] Different from the previous embodiment, in this embodiment, multiple electrode plates 40 are provided. Each electrode plate 40 is connected to the second positive electrode of the high-voltage generator 60 through a switch. In this way, the corresponding electrode plate 40 can be energized by turning on the corresponding switch, so as to adjust the offset angle of the jet trajectory.

[0050] It can be understood that the above two embodiments have their own advantages and disadvantages. In the case of a single electrode plate 40, a power device (such as a motor) needs to be additionally provided to drive the electrode plate 40 to rotate, but it can rotate to any position; in the case of multiple electrode plates 40, although the power device is less, the electrode plates 40 are also fixed, but additional switches need to be provided, and the positions of the electrode plates 40 cannot be adjusted and can only be selected at limited positions. For example, after 12 electrode plates 40 are evenly spaced along the circumferential direction, the corresponding angle of each electrode plate 40 is 30°.

[0051] It can be understood that the switches corresponding to two adjacent electrode plates 40 can also be turned on simultaneously. At this time, these two electrode plates 40 are equivalent to a large electrode plate 40, so that the adjustment of the electrode plate 40 will be more flexible.

[0052] In the above two embodiments, it is necessary to adjust the output voltage of the second positive electrode of the high-voltage generator 60 according to the first offset angle. In this way, a suitable repulsive force can be generated to roughly adjust the offset angle of the jet trajectory.

[0053] Please refer to Figure 7, in a specific embodiment of the present invention, step S240 includes: S241. Obtain a first prediction factor according to the first offset angle and a preset rough adjustment target angle of the jet trajectory; S242. Use a first PID controller based on a first BP neural network to control the output voltage of the second positive electrode of the high-voltage generator 60, wherein the input quantity of the first BP neural network includes the rough adjustment target angle of the jet trajectory, the first prediction factor, and the control signal output by the first PID controller.

[0054] In step S241, the rough adjustment target angle r_θ(k) of the jet trajectory can be set to 0°. When calculating the first prediction factor, first calculate the angle θ4 between the jet trajectory and the Z-axis according to the first offset angle, that is, the angle between the jet trajectory and the vertical direction, denoted as y_θ(k). At this time, the first prediction factor can be calculated according to the following formula:

[0055] ,

[0056] where A(k) is the first prediction factor, err_θ(i) is the difference between the rough adjustment target angle of the jet trajectory and the historical data of the angle between the current jet trajectory and the Z-axis, that is, err_θ(i)=r_θ(i)-y_θ(i), y_θ(k) is sampled in chronological order, k represents the sampling moment of the discrete time series, and A(k) is calculated based on the mean value of the previous k - 1 errors.

[0057] Figure 8 Schematically shows the schematic diagram of the first PID controller based on the first BP neural network. In this step, the structure of the first BP neural network can be, for example: the number of input layer nodes is 3, the number of hidden layer nodes is 40, and the number of output layer nodes is 3. After normalizing the rough adjustment target angle r_θ(k) of the jet trajectory, the first prediction factor A(k), and the control signal u_θ(k) output by the first PID controller, they are used as the input quantity of the first BP neural network, and the output quantity of the first BP neural network is the gain parameter K p 、K i 、K d . Through the self-learning ability of the first BP neural network, the three parameters K p 、K i 、K d are adjusted to adjust the first PID controller to the optimal state, where u_θ(k) is the control signal output by the first PID controller and is used to control the output voltage of the second positive electrode of the high-voltage generator 60.

[0058] It should be noted that the output voltage of the high-voltage generator 60 is generally in the range of thousands of volts. The control signal output by the first PID controller is, for example, a value between 0 and 1 (or 0 to 10). The control signal output by the first PID controller is not equal to the output voltage of the high-voltage generator 60. The output of the first PID controller is multiplied by a constant to obtain the output voltage of the high-voltage generator 60.

[0059] The above method of using the first PID controller based on the first BP neural network to adjust the output voltage of the high-voltage generator 60 has a fast adjustment speed and high accuracy. In addition, the output voltage of the high-voltage generator 60 can also be adjusted according to the following steps: (1) First, gradually increase the output voltage of the high-voltage generator 60 according to a preset voltage increment, and after each increase, re-obtain the first offset angle; (2) When the first offset angle is less than the set threshold, the rough adjustment is completed; when the first offset angle gradually increases, the output voltage of the high-voltage generator 60 is decreased. This adjustment process can also complete the rough adjustment of the jet trajectory, but the adjustment process takes a long time.

[0060] Step S300: Re-obtain the second offset angle of the jet trajectory after preliminary adjustment. After rough adjustment, the offset of the jet trajectory will be much less, but there may still be a small-angle offset at this time. In order to continue the fine adjustment of the jet trajectory, it is also necessary to first obtain the offset angle of the jet trajectory. The offset angle after rough adjustment can be recorded as the second offset angle.

[0061] In a specific embodiment of the present invention, in the step of re-obtaining the second offset angle of the jet trajectory after preliminary adjustment, the offset angle of the jet trajectory in the first direction and the offset angle in the second direction are used as the second offset angle. The reason for using the offset angles in two directions as the second offset angle here is that in the subsequent fine adjustment, we need to adjust the position of the equipotential ring 50 in two directions. Therefore, the fine adjustment can be performed according to the offset angles in two directions respectively.

[0062] Step S400: Control the horizontal position of the equipotential ring 50 located below the metal nozzle 10 according to the second offset angle to finely adjust the offset angle of the jet trajectory. The position of the equipotential ring 50 will directly affect the offset angle of the jet trajectory. Therefore, in the present invention, the offset angle of the jet trajectory is finely adjusted by precisely adjusting the position of the equipotential ring 50.

[0063] Please refer to Figure 9, in a specific embodiment of the present invention, controlling the horizontal position of the equipotential ring 50 located below the metal nozzle 10 according to the second offset angle includes: S410, controlling the movement of the equipotential ring 50 in the first direction according to the offset angle of the jet trajectory in the first direction and the preset fine-tuning target angle of the jet trajectory in the first direction; S420, controlling the movement of the equipotential ring 50 in the second direction according to the offset angle of the jet trajectory in the second direction and the preset fine-tuning target angle of the jet trajectory in the second direction. The preset fine-tuning target angle of the jet trajectory in the first direction and the preset fine-tuning target angle of the jet trajectory in the second direction can both be set to 0°, because the ultimate goal is to make the jet trajectory vertically downward.

[0064] When the composition of the solution sprayed from the metal nozzle 10 remains unchanged, the relationship between the offset angle of the jet trajectory in the first direction (or the second direction) and the movement distance of the equipotential ring 50 in the first direction (or the second direction) can be established through experiments. For example, first record the initial offset angle of the jet trajectory in the first direction, and then manually adjust the movement of the equipotential ring 50 in the first direction until the offset angle of the jet trajectory in the first direction becomes 0, record the initial offset angle and distance, and obtain a set of data; repeat the experiment multiple times to obtain multiple sets of data, and then fit the multiple sets of data to obtain the relationship formula between the offset angle and the movement distance. During subsequent fine-tuning, only need to substitute the offset angle into the fitted relationship formula to obtain the corresponding movement distance.

[0065] Please refer to Figure 10 , in a specific embodiment of the present invention, step S410 includes: S411, obtaining a second prediction factor according to the offset angle of the jet trajectory in the first direction and the preset fine-tuning target angle of the jet trajectory in the first direction; S412, using the second PID controller based on the second BP neural network (as Figure 11 shown) to control the output instruction of the motor controller. The motor controller controls the movement of the equipotential ring 50 in the first direction through the motor. Among them, the input quantities of the second BP neural network include the fine-tuning target angle of the jet trajectory in the first direction, the second prediction factor, and the control signal output by the second PID controller.

[0066] The above steps S411 and S412 are similar to the previous steps S241 and S242, except that the controlled objects are different. In this embodiment, the second PID controller outputs a distance value, which can be positive or negative, corresponding to the forward and reverse movements of the equipotential ring 50 along the X-axis (i.e., the first direction). After receiving the distance value output by the second PID controller, the motor controller can convert it into a control command to drive the motor to act, and the motor precisely controls the movement of the equipotential ring 50 along the first direction through the lead screw. It can be understood that the distance value output by the second PID controller can be normalized and needs to be multiplied by a certain coefficient to obtain the actual distance value to be adjusted, which is similar to the output of the first PID controller in the above embodiment.

[0067] The above steps S411 and S412 are only used to control the movement of the equipotential ring 50 along the first direction. In the same way, a third PID controller based on the third BP neural network can be constructed (as Figure 12 shown) to control the movement of the equipotential ring 50 along the second direction, and its control method is exactly the same.

[0068] It should be noted that the step division of the above various methods is only for clear description. When implemented, they can be combined into one step or some steps can be split into multiple steps. As long as the same logical relationship is included, they are all within the protection scope of this application; adding insignificant modifications or introducing insignificant designs to the algorithm or process, but not changing the core design of its algorithm and process, are all within the protection scope of this patent.

[0069] Generally speaking, this method coarsely adjusts the deflection angle of the jet trajectory by setting the electrode plate 40 beside the jet trajectory and using the repulsive force generated by the electrode plate 40, and then finely adjusts the deflection angle of the jet trajectory by adjusting the horizontal position of the equipotential ring 50, so as to make the jet trajectory as vertical as possible, ensure that the spraying direction of the liquid droplets is basically consistent with the gravity direction, and thus avoid the problem of uneven microspheres / microcapsules formed by the liquid droplets.

[0070] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A control method for adjusting the jet trajectory, characterized in that, Including: Obtaining images of the jet trajectory when the Taylor cone angle of the metal nozzle captured by the first camera and the second camera is in a stable state, wherein the central axes of the first camera and the second camera are both located in the horizontal plane and are perpendicular to each other; Processing the image captured by the first camera to obtain the deviation angle θ1 of the jet trajectory in the first direction; Processing the image captured by the second camera to obtain the deviation angle θ2 of the jet trajectory in the second direction; Calculating the first deviation angles (θ3, θ4) according to the deviation angle θ1 of the jet trajectory in the first direction and the deviation angle θ2 in the second direction, wherein θ3 is the angle between the jet trajectory and the positive direction of the X-axis in the XOY plane, and θ4 is the angle between the jet trajectory and the Z-axis; Controlling the voltage on the electrode plate located beside the jet trajectory according to the first deviation angles to coarsely adjust the deviation angle of the jet trajectory; Obtaining again the second deviation angles (θ1, θ2) of the jet trajectory after preliminary adjustment; Controlling the isopotential ring to move in the first direction according to the deviation angle θ1 of the jet trajectory in the first direction and the preset fine-tuning target angle of the jet trajectory in the first direction; controlling the isopotential ring to move in the second direction according to the deviation angle θ2 of the jet trajectory in the second direction and the preset fine-tuning target angle of the jet trajectory in the second direction; for finely adjusting the deviation angle of the jet trajectory; the isopotential ring is located below the metal nozzle and the electrode plate, and the jet trajectory passes through the isopotential ring; The metal nozzle and the isopotential ring are respectively connected to the positive electrode and the negative electrode of the high-voltage generator; the high-voltage generator is further provided with a second positive electrode, and the electrode plate is connected to the second positive electrode; There is one electrode plate; controlling the voltage on the electrode plate located beside the jet trajectory according to the first deviation angles includes: moving the electrode plate to the side where the jet trajectory deviates according to θ3 in the first deviation angles; adjusting the output voltage of the second positive electrode of the high-voltage generator according to θ4 in the first deviation angles, or There are multiple electrode plates, and the multiple electrode plates are evenly spaced along the circumferential direction. Each electrode plate is respectively connected to the second positive electrode of the high-voltage generator through a switch; controlling the voltage on the electrode plate located beside the jet trajectory according to the first deviation angles includes: determining one or two adjacent electrode plates among the multiple electrode plates that are located on the side where the jet trajectory deviates according to θ3 in the first deviation angles; turning on the switches corresponding to one or two adjacent electrode plates located on the side where the jet trajectory deviates; adjusting the output voltage of the second positive electrode of the high-voltage generator according to θ4 in the first deviation angles.

2. The control method for adjusting the jet trajectory according to claim 1, characterized in that Adjusting the output voltage of the second positive electrode of the high-voltage generator according to θ4 in the first deviation angles includes: Obtaining a first prediction factor according to θ4 in the first deviation angles and the preset coarse-tuning target angle of the jet trajectory; The output voltage of the second positive electrode of the high-voltage generator is controlled by using a first PID controller based on a first BP neural network, wherein the input quantities of the first BP neural network include the rough adjustment target angle of the jet trajectory, the first prediction factor, and the control signal output by the first PID controller.

3. The control method for adjusting the jet trajectory according to claim 1, characterized in that, Controlling the equipotential ring to move in the first direction according to the offset angle of the jet trajectory in the first direction and the preset fine adjustment target angle of the jet trajectory in the first direction, includes: Obtaining a second prediction factor according to the offset angle of the jet trajectory in the first direction and the preset fine adjustment target angle of the jet trajectory in the first direction; The output command of the motor controller is controlled by using a second PID controller based on a second BP neural network, and the motor controller controls the equipotential ring to move in the first direction through a motor, wherein the input quantities of the second BP neural network include the fine adjustment target angle of the jet trajectory in the first direction, the second prediction factor, and the control signal output by the second PID controller.

Images