Disclosure of Invention
The embodiment of the invention provides a device for detecting the flame diameter of a plasma arc and a control method, which are used for solving the problem that the quality of powder is influenced because the power density of the plasma arc cannot be controlled in the existing plasma rotating electrode powder manufacturing process.
The embodiment of the invention provides a device for detecting the flame diameter of a plasma arc, which comprises: the plasma arc flame diameter determining unit is connected with the plasma power supply control system;
the image acquisition unit is electrically connected with the plasma arc flame diameter determination unit and is used for sending the acquired plasma arc flame diameter original image and the plasma arc flame diameter detection image to the plasma arc flame diameter determination unit;
the plasma arc flame diameter determining unit is used for determining a second plasma arc flame diameter of the plasma arc flame included in the detection image according to the original image, the detection image and a first plasma arc flame diameter corresponding to the original image, and sending the second plasma arc flame diameter to the main control system;
the main control system sends a control instruction to the plasma power supply control system according to the comparison result of the second plasma arc flame diameter with the maximum plasma arc flame diameter and the minimum plasma arc flame diameter respectively, wherein the control instruction comprises an increase current signal or a decrease current signal;
the plasma power supply control system is electrically connected with the main control system and used for controlling the current supplied to the plasma gun to increase or decrease according to the control instruction sent by the main control system.
Preferably, the plasma power control system is further configured to: and according to the set value provided by the main control system, increasing the current according to the set value, and respectively providing the current increased according to the set value to the plasma gun.
Preferably, the image acquisition unit comprises an industrial camera and a high-power light source;
the acquiring of the original image by the image acquisition unit specifically includes:
when the main arc current of the plasma power supply increases progressively according to the set numerical value, the industrial camera shoots a flame diameter image of the plasma arc, the shot image is determined to be an original image, and each original image corresponds to the flame diameter of each plasma arc.
The image acquisition unit acquires the detection image, and specifically includes:
when the plasma powder process equipment starts to process powder, the industrial camera shoots plasma arc flame, and the shot image is determined as the detection image.
Preferably, the plasma arc flame diameter determining unit is configured to determine a second plasma arc flame diameter of the plasma arc flame included in the detected image according to the original image, the detected image, and a first plasma arc flame diameter corresponding to the original image, and specifically includes:
comparing and identifying the plurality of detection images with the plurality of original images respectively, and if the flame forms of at least one detection image and at least one original image are the same, determining the determined detection image as a first detection image;
and determining a first plasma arc flame diameter corresponding to the original image matched with the first detection image as a second plasma arc flame diameter of the first detection image.
The embodiment of the invention also provides a control method for detecting the flame diameter of the plasma arc, which comprises the following steps:
determining the second plasma arc flame diameter of the current plasma arc flame according to the received original image and the detected image;
and sending a control command to a plasma power supply control system according to the comparison result of the second plasma arc flame diameter with the maximum plasma arc flame diameter and the minimum plasma arc flame diameter respectively, wherein the control command comprises an increase current signal or a decrease current signal.
Preferably, before determining the second plasma arc flame diameter of the current plasma arc flame, the method further comprises:
segmenting according to a set numerical value according to a difference value between the maximum diameter of the plasma arc flame and the minimum diameter of the plasma arc flame, dividing current provided for a plasma gun into a plurality of plasma power supply main arc currents according to the set numerical value, shooting the diameter of the plasma arc flame by using an industrial camera when the plasma power supply main arc currents change, and determining a shot image as the original image;
when the plasma powder making equipment starts to make powder, the diameter of the flame of the plasma arc is shot, and the shot image is determined as the detection image.
Preferably, the determining a second plasma arc flame diameter of the current plasma arc flame specifically comprises:
comparing and identifying the plurality of detection images with the plurality of original images respectively, and if the flame forms of at least one detection image and at least one original image are the same, determining the determined detection image as a first detection image;
and determining a first plasma arc flame diameter corresponding to the original image matched with the first detection image as a second plasma arc flame diameter of the first detection image.
The embodiment of the invention provides a device for detecting the flame diameter of a plasma arc, which comprises: the plasma arc flame diameter determining unit is connected with the plasma power supply control system; the image acquisition unit is electrically connected with the plasma arc flame diameter determination unit and is used for sending the acquired plasma arc flame diameter original image and the plasma arc flame diameter detection image to the plasma arc flame diameter determination unit; the plasma arc flame diameter determining unit is used for determining a second plasma arc flame diameter of the plasma arc flame included in the detection image according to the original image, the detection image and a first plasma arc flame diameter corresponding to the original image, and sending the second plasma arc flame diameter to the main control system; the main control system sends a control instruction to the plasma power supply control system according to the comparison result of the second plasma arc flame diameter with the maximum plasma arc flame diameter and the minimum plasma arc flame diameter respectively, wherein the control instruction comprises an increase current signal or a decrease current signal; the plasma power supply control system is electrically connected with the main control system and used for controlling the current supplied to the plasma gun to increase or decrease according to the control instruction sent by the main control system. An image acquisition unit and a plasma arc flame diameter determining unit are introduced into the device, and the mode of detecting the flame diameter of the plasma arc is combined with an automatic control system, so that the diameter of the plasma arc can be accurately displayed in real time; the diameter of the plasma arc is accurately detected, so that the power density of the plasma arc can be accurately detected, the influence of the plasma arc on the quality of the metal powder is controlled, and the powder making process is greatly improved; furthermore, the device can enable the automation degree of the plasma powder manufacturing equipment to enter a full-automatic era from semi-automation, and solves the problem that the plasma rotating electrode powder manufacturing process in the prior art has influence on the powder quality because the plasma arc power density cannot be controlled.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic structural diagram of a plasma powder manufacturing apparatus provided in the prior art, and as shown in fig. 1, the plasma powder manufacturing apparatus includes an atomizing chamber, a plasma gun and a metal bar. The plasma arc flame is between the plasma gun and the metal bar, and can be determined according to the content recorded in the background technology, when the distance between the plasma gun and the melting end face of the metal bar is larger, the arc breakage of the plasma arc is easily caused; when the distance between the plasma gun and the melting end face of the metal bar is relatively small, the plasma gun is easily damaged, and even the plasma gun and the melting end face of the metal bar collide with each other.
Because the existing plasma powder manufacturing equipment can not realize full-automatic control, therefore, the distance between the melting end faces of the plasma gun and the metal bar can not be detected in real time, and the main difficulty of causing the problems is as follows:
1) plasma arcs generated by the plasma rotating electrode powder manufacturing equipment can reach ten thousand degrees instantly, so that the temperature in the atomizing chamber is increased rapidly, the atomizing chamber is kept at a high temperature in the powder manufacturing process, and the temperature sensitive detection element cannot work;
2) the atomization chamber for producing the powder is filled with argon, so that the argon is easy to ionize, and most circuit boards are short-circuited, so that the powder cannot work normally; in addition, a large amount of metal dust floats in the atomizing chamber, so that the working condition environment is extremely complex to detect.
Based on the technical scheme, the embodiment of the invention provides a device for detecting the flame diameter of a plasma arc, wherein an image acquisition unit and a plasma arc flame diameter determination unit are added in the device. The plasma arc flame diameter determining unit is mainly used for determining the plasma arc flame diameter corresponding to the detected image according to the original image and the detected image determined by the image acquisition unit.
The image acquisition unit also comprises an industrial camera mounting bracket, a filter and the like. Specifically, the industrial camera is fixed on an industrial camera mounting bracket, and the industrial camera mounting bracket and the high-power light source are both fixed in an atomizing chamber of the plasma powder manufacturing equipment.
In practical application, the lens of the industrial camera is installed in parallel with the plasma gun, namely the industrial camera is used for shooting plasma arc flame emitted by the plasma gun. In order to ensure that the photographed plasma arc flame has a good effect, a filter is preferably further disposed in front of the lens of the industrial camera.
FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an apparatus for detecting a flame diameter of a plasma arc, which may be used in at least a plasma pulverizing apparatus.
As shown in FIG. 2, the device mainly comprises a plasma power supply control system 40, a plasma arc flame diameter determination unit 30, an image acquisition unit 20 and a main control system 10.
The image acquisition unit 20 is electrically coupled with the plasma arc flame diameter determination unit 30 and the master control system 10, respectively. On one hand, the image acquisition unit 20 acquires an original image and a detection image according to the received control information sent by the main control system 10; on the other hand, the image acquisition unit is used for sending the acquired original image and the detected image to the plasma arc flame diameter determination unit 30.
Specifically, the main control system 10 determines the maximum diameter of the plasma arc flame and the minimum diameter of the plasma arc flame according to the experimental values before sending the collected original image to the image collecting unit 20, and may determine the adjustable value of the flame diameter of the plasma arc according to the difference between the determined maximum diameter of the plasma arc flame and the determined minimum diameter of the plasma arc flame, that is, the flame diameter of the plasma arc may be between the maximum flame diameter and the minimum flame diameter.
In practical application, if the diameter of the metal bar is kept constant, if the energy density is too high, energy waste is more, and in addition, the melting speed of the metal bar is too high, the prepared powder becomes coarse, and when the energy density is too low, the bar cannot be melted. Since the energy density is related to the main arc current of the plasma power supply, when the adjustable value of the flame diameter of the plasma arc and how many sections the adjustable value of the flame diameter of the plasma arc can be split are determined, accordingly, how many sections the main arc current of the plasma power supply is divided into is also determined.
Here, the number of stages into which the plasma flame diameter adjustable value is divided is equal to the number of stages into which the main arc current of the plasma power supply is divided. For example, if the main arc current of the plasma power supply is I, if I is divided into N, the main arc current of the plasma power supply sequentially is:
correspondingly, if the length value of the minimum flame diameter of the plasma arc is 1mm and the length value of the maximum flame diameter of the plasma arc is 5mm, the minimum length for dividing 4mm is determined, namely the value of the minimum flame diameter of the plasma arc which increases each time is determined, if the minimum length for dividing 4mm is 1mm, the value of the maximum flame diameter of the plasma arc which increases each time is 1mm, and the minimum flame diameters of the plasma arcs are sequentially as follows: 1mm, (1+1) mm, (1+2) mm and (1+3) mm.
Based on this, it can be determined that the flame diameter of the plasma arc can be determined according to the following formula (1) in the embodiment of the present invention:
in the formula (1), DmaxMaximum flame diameter for a plasma arc; dminThe minimum flame diameter of a plasma arc; delta D is a set distance which is maximally equal to the difference between the maximum flame diameter of the plasma arc and the minimum flame diameter of the plasma arc, namely delta D is less than or equal to Dmax-Dmin;DxThe flame diameter of the plasma arc is between D and DmaxAnd DminTo (c) to (d); x is a natural number, when x is 0, then DxEqual to the minimum flame diameter of the plasma arc.
After the main arc current value of each plasma arc power supply is determined, the flame diameter of each plasma arc corresponding to the main arc current of each plasma arc power supply can be photographed, namely, the flame diameter of each plasma arc is photographed by adopting an image acquisition system. Based on this, the
main control system 10 can respectively send a set value instruction and a collection instruction to the plasma power control system and the image collection unit according to the determined main arc current values of the plurality of plasma power supplies. After the plasma power supply control system receives a set numerical value instruction sent by the main control system, according to specific numerical values included by the numerical value instruction, main arc current which is provided for the plasma gun and sequentially increases according to the set data is provided, correspondingly, the image acquisition unit can shoot the flame diameter of each plasma arc corresponding to the main arc current of each plasma arc power supply according to an acquisition instruction sent by the main control system, namely, the image acquisition system is adopted to shoot the flame diameter of each plasma arc, for example, if a plurality of determined main arc current values of each plasma power supply are sequentially:

the flame diameter of each plasma arc is D in turn
min、D
min+Δd、D
min+2Δd、D
minD.. Dmax, and accordingly, a plurality of photographs may be taken in sequence.
In the embodiment of the invention, the picture taken at the moment is determined as an original image, and the original image is matched and stored with the flame diameter of each plasma arc. For example, the original image 1 and the plasma power source have a main arc current value of 1 and a flame diameter of a plasma arc of DminThe original image 2 is matched with the plasma power supply, the main arc current value of the plasma power supply is 2, the flame diameter of the plasma arc is Dmin+ delta D is matched, the original image 3 and the plasma power supply main arc current value are 3 plasma arcs, and the flame diameter is Dmin+2 Δ d, original image 4 and plasma power main arcThe flame diameter of the plasma arc was D at a current value of 4min+3 Δ d, and so on, all the original images taken can be matched to the flame diameter of each plasma arc.
It should be noted that, in the embodiment of the present invention, after all the original images are matched with the flame diameter of each plasma arc and the plasma power supply main arc current value, the matching result may be stored in a set area.
When the plasma powder making equipment starts to make powder, the diameter of the plasma arc flame is shot, and the shot image is determined as a detection image.
In the embodiment of the invention, when the plasma powder-making equipment starts to make powder, the molten end surface of the metal bar stock approaches to the plasma gun according to the set feeding speed. Based on this, it is necessary to determine the shooting speed of the plasma arc flame diameter by the industrial camera to be at least 5 detection images per second.
Further, when the feeding speed of the melting end face of the metal bar is determined to be 1.0-2.0 mm/s generally, the requirement of the whole melting system on the feeding precision is not very high, and the number of pictures taken per second is 10, the shooting distance precision can reach 0.1-0.2 mm/s, and the precision can completely meet the use requirement, so that the shooting speed of the industrial camera on the diameter of the plasma arc flame can be determined to be less than 10 detection images per second.
After the image acquisition unit 20 sequentially acquires the plasma arc flame diameter original image and the plasma arc flame diameter detection image, the images can be sent to the plasma arc flame diameter determination unit.
In the embodiment of the invention, the plasma arc flame diameter determining unit compares and identifies a plurality of shot detection images with the stored original images.
When the flame shape of at least one detection image is the same as that of one original image, determining a first detection image of the detection image.
Further, the first plasma arc flame diameter corresponding to the original image matched with the first detection image is determined, a second plasma arc flame diameter corresponding to the first detection image is determined, and the second plasma arc flame diameter is sent to the main control system 10.
When the main control system 10 receives the second plasma arc flame diameter sent by the plasma arc flame diameter determining unit, the second plasma arc flame diameter is respectively compared with the maximum plasma arc flame diameter and the minimum plasma arc flame diameter, and according to the comparison result, a control instruction is determined to be sent to the plasma power supply control system 40 electrically connected with the main control system 10.
Specifically, in the embodiment of the present invention, if the main control system 10 determines that the diameter of the second plasma arc flame is smaller than the maximum diameter of the plasma arc flame, the main control system 10 sends an increase current signal to the plasma power supply control system, and when the plasma power supply control system receives the increase current signal command, the plasma power supply control system increases the current by Δ a based on the existing melting current until the diameter of the second plasma arc flame is equal to the maximum diameter of the standard plasma arc. In practical applications, Δ a is a first-gear current value, and the current value is preferably 100A.
If the main control system 10 determines that the second plasma arc flame diameter is greater than the maximum plasma arc flame diameter, the main control system 10 sends a current reduction signal to the plasma power control system, and when the plasma power control system receives the current reduction signal command, the plasma power control system reduces the current by Δ a on the basis of the existing melting current until the second plasma arc flame diameter is equal to the standard maximum plasma arc diameter. In practical applications, Δ a is a first-gear current value, and the current value is preferably 100A.
In conclusion, the device is provided with the image acquisition unit and the plasma arc flame diameter determination unit, and the mode of detecting the flame diameter of the plasma arc is combined with the automatic control system, so that the diameter of the plasma arc can be accurately displayed in real time; the diameter of the plasma arc is accurately detected, so that the power density of the plasma arc can be accurately detected, the influence of the plasma arc on the quality of the metal powder is controlled, and the powder making process is greatly improved; furthermore, the device can enable the automation degree of the plasma powder manufacturing equipment to enter a full-automatic era from semi-automation, and solves the problem that the plasma rotating electrode powder manufacturing process in the prior art can not control the power density of a plasma arc, so that the quality of powder is influenced.
Based on the same inventive concept, the embodiment of the invention provides a control method for detecting the flame diameter of a plasma arc, and as the principle of solving the technical problem of the method is similar to that of a device for detecting the flame diameter of the plasma arc, the implementation of the method can be referred to the implementation of the method, and repeated parts are not described again.
Fig. 4 is a flow chart illustrating a control method for detecting a flame diameter of a plasma arc according to an embodiment of the present invention, as shown in fig. 4, the method mainly includes the following steps:
step 101, determining a second plasma arc flame diameter of the current plasma arc flame according to the received original image and the detected image;
and 102, sending a control instruction to a plasma power supply control system according to the comparison result of the second plasma arc flame diameter with the maximum plasma arc flame diameter and the minimum plasma arc flame diameter respectively, wherein the control instruction comprises an increase current signal or a decrease current signal.
It should be noted that the control method for detecting the flame diameter of the plasma arc provided by the embodiment of the invention is based on the device for detecting the flame diameter of the plasma arc, namely, the control method needs to be executed depending on the device for detecting the flame diameter of the plasma arc.
The execution main body of the control method is a main control system. Specifically, before step 101, the high-power light source and the industrial camera included in the image processing device are disposed in the atomization chamber, and after the high-power light source and the industrial camera are disposed in the atomization chamber, a picture of plasma arc flame generated by a plasma gun disposed in the atomization chamber can be acquired by the industrial camera.
When the plasma gun is started to maintain the arc, it is extremely important to accurately detect the distance between the plasma gun and the melted end face of the metal bar. If the distance between the plasma gun and the melting end face of the metal bar is larger, the plasma arc is easy to break; if the distance between the plasma gun and the melting end face of the metal bar is relatively small, the plasma gun is easily damaged, and even the plasma gun and the melting end face of the metal bar collide with each other. In practical application, when the plasma gun is not ignited, because a piece of paint black is in the atomizing chamber, in order to enable the industrial camera to shoot the position between the plasma gun in the atomizing chamber and the molten end face of the metal bar, a light source needs to be provided in the atomizing chamber. In the embodiment of the invention, the high-power light source can be arranged in the atomizing chamber, and based on the high-power light source, the high-power light source can provide brightness for the shooting of an industrial camera.
Fig. 3 is a schematic structural diagram of a plasma powder manufacturing apparatus according to an embodiment of the present invention, and as shown in fig. 3, the plasma powder manufacturing apparatus at least includes an atomizing chamber, a high power light source, an industrial camera, a plasma gun, and a metal bar.
Specifically, the atomizing chamber is cylindrical, the high-power light source is arranged on the central shaft of the atomizing chamber, and the high-power light source is positioned above the melting end face of the plasma gun and the metal bar. Further, the industrial camera is arranged on the central shaft of the atomizing chamber, and the industrial camera is arranged above the high-power light source.
It should be noted that, because the atomizing chamber is a cylinder, the central axis of the atomizing chamber is a connection line of the centers of the upper surface and the lower surface of the cylinder, that is, the high-power light source is disposed at the center of the cross section of the atomizing chamber, in practical application, the specific position of the high-power light source on the central axis is not limited (above the plasma gun and the metal bar), and only the high-power light source is ensured not to affect the plasma gun when operating, and the plasma gun does not affect the high-power light source when operating.
As shown in fig. 3, the industrial camera is arranged above the atomizing chamber, i.e. the industrial camera is arranged on the extension line of the central shaft of the atomizing chamber, and the lens of the industrial camera is parallel to the plasma gun and the metal bar.
After the industrial camera and the high-power light source are arranged, the high-power light source can be started, and after the high-power light source illuminates the atomizing chamber, the industrial camera can clearly shoot the distance between the plasma gun and the melted end face of the metal bar.
Furthermore, according to the device for detecting the flame diameter of the plasma arc, the main control system determines the adjustable value of the flame diameter of the plasma arc, the flame diameters of the plasma arcs and the main arc current of the plasma power supply according to the maximum diameter of the flame of the plasma arc and the minimum diameter of the flame of the plasma arc. And then sequentially acquiring an original image and a detection image under the control of the main control system according to the image acquisition unit, and sending the acquired original image and the detection image to the main control system.
In step 101, the main control system compares and identifies a plurality of shot detection images with stored original images according to the received original images and detection images.
When the flame shape of at least one detection image is the same as that of one original image, determining a first detection image of the detection image. And determining the first plasma arc flame diameter corresponding to the original image matched with the first detection image as the second plasma arc flame diameter of the first detection image.
In step 102, when the main control system receives a second plasma arc flame diameter, comparing the second plasma arc flame diameter with the plasma arc flame maximum diameter and the plasma arc flame minimum diameter respectively, and determining to send a control instruction to a plasma power control system electrically connected with the main control system according to a comparison result, wherein the control instruction comprises an increase current signal or a decrease current signal.
Specifically, if the main control system 10 determines that the diameter of the second plasma arc flame is smaller than the maximum diameter of the plasma arc flame, the main control system 10 will send an increase current signal to the plasma power control system, when the plasma power control system receives the increase current signal command, the PLC controller will increase the current Δ a (preferably 100A for first gear) based on the existing melting current, until the diameter of the second plasma arc flame is equal to the standard plasma arc maximum diameter system 10, determines that the diameter of the second plasma arc flame is larger than the maximum diameter of the plasma arc flame, the main control system 10 will send a decrease current signal to the plasma power control system, when the plasma power control system receives the decrease current signal command, the PLC controller will decrease the current Δ a (preferably 100A for first gear) based on the existing melting current, in conclusion, the embodiment of the invention provides a device set control method for detecting the flame diameter of a plasma arc, which is characterized in that an image acquisition unit and a plasma arc flame diameter determining unit are introduced into the device, and the mode of detecting the flame diameter of the plasma arc is combined with an automatic control system, so that the diameter of the plasma arc can be accurately displayed in real time; the diameter of the plasma arc is accurately detected, so that the power density of the plasma arc can be accurately detected, the influence of the plasma arc on the quality of the metal powder is controlled, and the powder making process is greatly improved; furthermore, the device can enable the automation degree of the plasma powder manufacturing equipment to enter a full-automatic era from semi-automation, and solves the problem that the plasma rotating electrode powder manufacturing process in the prior art can not control the power density of a plasma arc, so that the quality of powder is influenced.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such 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 intended to include such modifications and variations.