A transfer device for metal powder processing and its operation method

Abstract

The present invention proposes a transfer device for metal powder processing and an operating method thereof, which belongs to the technical field of metal powder processing and solves the problem that the gravity dumping method used in the metal powder processing process is difficult to achieve precise control and has a low degree of automation. The transfer device includes: an operating container, an infrared camera, a laser ranging device and a downstream process container; the downstream process container is provided with a funnel-shaped opening, the operating container is used to hold metal in a molten state and pour it into the downstream process container, the molten metal forms a metal retention area at the narrow mouth position of the funnel opening, the laser ranging device is used to measure the distance between the metal retention area and the molten metal in the downstream process container, and the infrared camera is used to locate the downstream molten metal surface.

Description

Technical Field

[0001] The invention relates to a transfer device for metal powder processing and an operating method thereof, belonging to the technical field of metal powder processing. Background Art

[0002] In the metal powder processing technology, the usual process is to heat and melt the metal powder and then transfer it to the next step. In this transfer process, gravity pouring is often used, and the molten powder is usually transferred from one step to another by controlling the tilt angle of the heating container. This method has a relatively simple structure, but it requires control of key parameters such as pouring speed and pouring angle, which is usually achieved by a hydraulic transfer device. In order to ensure the stability of the transfer process, it is crucial to control the pouring speed, pouring angle, and the timing of starting and stopping the pouring. However, since the heating container and the transfer container are usually made of high-temperature resistant materials such as ceramics, and the high-temperature environment involved in the production process, it is difficult to use weighing measurement to monitor the pouring process. Therefore, it traditionally relies on manual visual observation and adjusts the pouring speed and angle through hydraulic control valves. There are the following defects: 1. It is difficult to achieve precise control: Metal powder in a molten state has fluidity and high-temperature characteristics. The use of gravity pouring is easily affected by the pouring angle and speed, and it is difficult to ensure the uniformity of the powder flow. During the pouring process, temperature fluctuations and the surface tension of the molten metal can lead to unstable flow, affecting the quality of subsequent processes. 2. Low degree of automation: Although some mechanical equipment and pumping transfer devices can achieve a certain degree of automation, existing technologies often require a lot of manual intervention during the transfer of high-temperature, molten powders. In particular, there is a lack of automatic closed-loop control of the transfer device when controlling the flow rate and flow rate of the molten powder. This not only increases operational difficulty but also easily leads to errors, affecting production efficiency and product quality.

[0003] Therefore, existing technologies for transporting molten metal powder still have shortcomings in terms of precise control, temperature management, automation, and material waste, creating an urgent need for a more efficient, safe, and highly automated solution. This invention utilizes infrared thermal imaging, spatial positioning, and laser measurement technology for observation, and introduces a dynamic closed-loop transport device to achieve linear control of the operation process, ensuring high efficiency and stability. Summary of the Invention

[0004] The present invention aims to solve the problem of difficulty in achieving precise control and low automation in the metal powder processing process using the gravity dumping method, and further proposes a transfer device for metal powder processing and an operation method thereof, wherein the transfer device includes: an operating container, an infrared camera, a laser distance measuring device and a downstream process container;

[0005] A funnel-shaped opening is provided on the downstream process container. The operating container is used to hold molten metal and pour it into the downstream process container. The molten metal forms a metal retention area at the narrow mouth of the funnel-shaped opening. The laser ranging device is used to measure the distance between the metal retention area and the molten metal downstream of the downstream process container. The infrared camera is used to locate the surface of the molten metal liquid downstream. The pouring angle of the operating container is controlled by a closed loop to complete the transfer of the molten metal.

[0006] A method for using a transfer device for metal powder processing, comprising:

[0007] Step 1: Perform offline calibration on the operating vessel, infrared camera, laser rangefinder, and downstream process vessel. Establish a common coordinate system for observations based on the offline parameters of the infrared camera, laser rangefinder, and downstream process vessel. Initialize the parameters of the transfer device using the physical parameters obtained from the offline calibration of the operating vessel.

[0008] Step 2: Calculate the volume of molten metal in the downstream process vessel online to obtain the required pouring speed of the operating vessel;

[0009] Step 3: Perform online control of the transfer device according to the dumping speed requirements of the operating container to complete the dumping of the metal powder.

[0010] Optionally, the step of completing the initialization parameters of the transfer device in step 1 includes:

[0011] Step 1.1: Record the volume and shape parameters of the operating container, mathematically model the inner cavity of the operating container based on the volume and shape parameters, obtain the relationship between the pouring angle and the volume of liquid flowing out per unit time, and obtain the physical parameters of the operating container;

[0012] Step 1.2: Calibrate the infrared camera's internal parameters using a panel with infrared LEDs. Perform spatial calibration between the infrared camera's coordinate system and the physical coordinate system of the downstream process container to complete the infrared camera's external parameter calibration.

[0013] Step 1.3: Record the volume and shape parameters of the downstream process container, perform mathematical modeling on the inner cavity of the physical parameters of the downstream process container based on the volume and shape parameters, and complete the physical parameter calibration of the downstream process container;

[0014] Step 1.4: Calibrate the zero point of the laser distance measuring device and the physical coordinate system of the downstream process container to complete the calibration of the laser distance measuring device;

[0015] Step 1.5: Establish a unified coordinate system for the observed quantities by calibrating the downstream process container, laser rangefinder, and infrared camera. Initialize the parameters of the transfer device by measuring the physical parameters of the operating container.

[0016] Optionally, the step of online calculating the volume of the metal in the molten state in the downstream process container in step 2 includes:

[0017] Step 2.1: The laser measuring device is directed at a certain angle to the surface of the molten metal liquid, measures the distance to the molten metal liquid surface, and calculates the position of the molten metal liquid surface in the downstream process container at this time;

[0018] Step 2.2: Observe the surface with an infrared camera, accurately locate and model the molten metal surface using spatial positioning technology and offline calibration parameters to obtain infrared measurement results.

[0019] Step 2.3: Calculate the retained metal volume in the downstream process container and the remaining volume redundancy V1 in the downstream process container using the laser measurement device measurement results, the infrared measurement results, and the physical parameters of the downstream process container;

[0020] Step 2.4: Calculate the volume of molten metal outflow per unit time through mathematical modeling of the operating vessel, and estimate the volume V2 of free metal liquid in the air that has been poured out of the vessel and has not reached the downstream process vessel based on time;

[0021] Step 2.5: Model the flow transfer device based on the remaining volume redundancy V1 and the estimated volume V2 of free liquid metal in the air, estimate the upper limit Vt of the dumping volume per unit time, combine Vt with the mathematical modeling of the operating container to calculate the upper limit Ang of the dumping angle, and calculate the dumping angle Ang-t' at the next moment through Kalman filtering.

[0022] Optionally, the step of performing online control of the transfer device according to the requirement of the dumping speed of the operating container in step 3 includes:

[0023] Step 3.1: Run the transfer device and automatically control the container to start dumping;

[0024] Step 3.2: All physical parameters of the initial dumping are obtained through step 1, and the transfer device controls the operating container to start dumping at a fixed speed;

[0025] Step 3.3: The transfer device controls the hydraulic mechanism to automatically adjust the dumping angle according to the operating container angle calculated in real time in step 2.5;

[0026] Step 3.4: When the dumping angle is greater than the critical value or the observed volume of the downstream process container is greater than the critical value, the transfer device completes the dumping.

[0027] The beneficial effects of the present invention are:

[0028] 1. The present invention can realize automatic dumping, close the dumping process, and ensure the stability and safety of dumping;

[0029] 2. The present invention can use an automated method to perform observations, thus avoiding the instability of manual observations. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of a transfer device for metal powder processing provided by the present invention;

[0031] Figure 2 The present invention provides a flow chart of the operation of a transfer device for metal powder processing. DETAILED DESCRIPTION

[0032] Specific implementation method 1: Combination Figure 1 This embodiment is described as follows. Figure 1 As shown, the structure of a transfer device for metal powder processing described in this embodiment includes: an operating container, an infrared camera, a laser distance measuring device and a downstream process container;

[0033] The infrared camera model used in this embodiment is Hikvision MV-CI003-GL-N6, which has the following functions: 1. It uses a 300,000-pixel, high-sensitivity vanadium oxide uncooled detector; 2. It supports multiple pseudo-color modes, grayscale alarms, and rich image adjustment functions; 3. It is compact in size and supports four-sided installation; 4. It uses a Gigabit Ethernet interface, and the maximum transmission distance can reach 100m without a relay; 5. It is compatible with the GigE Vision protocol and GenlCam standard.

[0034] The laser distance measuring device used in this embodiment is of the model KJT-KDA-TR-II, which has the following functions: 1. It is specially used to measure the height of the molten aluminum / molten steel level under various working conditions, and is used for displaying and closed-loop controlling the molten aluminum level; 2. It can maintain high measurement accuracy and reliability in harsh outdoor environments; 3. It uses a visible laser beam, which is easy to aim at the object being measured; 4. The length of the connecting cable can be extended, and the measurement range of the molten aluminum level can reach 10m; 5. Various functional instructions can be input by a computer; 6. Different parameters can be used to program the switch output and analog output separately; 7. The alarm distance range can be set arbitrarily; 8. The output unit of the measurement value can be set arbitrarily; 9. An external trigger can be used to realize remote trigger measurement.

[0035] A funnel-shaped opening is provided on the downstream process container. The operating container is used to hold molten metal and pour it into the downstream process container. The molten metal forms a metal retention area at the narrow mouth of the funnel-shaped opening. The laser ranging device is used to measure the distance between the metal retention area and the molten metal downstream of the downstream process container. The infrared camera is used to locate the surface of the molten metal liquid downstream. The pouring angle of the operating container is controlled by a closed loop to complete the transfer of the molten metal.

[0036] Specific implementation method 2: Combination Figure 2 This embodiment is described as follows. Figure 2 As shown, the steps of the operation method of a transfer device for metal powder processing described in this embodiment include:

[0037] a: Offline calibration;

[0038] Since the transfer device is equipped with multiple measurement units, a control unit, and multiple containers, and its online operating parameters cannot be directly observed, the transfer device uses offline calibration to measure and calibrate multiple units so that the measurement and control process can be carried out in the same scale coordinate system during online operation;

[0039] a1: physical parameters of the operating container;

[0040] The physical parameter calibration of the operating container requires recording the volume and shape parameters of the operating container, mathematically modeling the inner cavity of the operating container based on the volume and shape parameters, and completing the relationship between the pouring angle and the volume of liquid flowing out per unit time.

[0041] a2: infrared camera parameters;

[0042] The parameters of the infrared camera are divided into internal and external parameter calibration. The calibration of the camera's internal parameters is carried out through a panel with infrared LED beads. The calibration of the infrared camera's external parameters mainly completes the spatial calibration of the infrared camera's coordinate system and the physical coordinate system of the downstream process container.

[0043] a3: physical parameters of downstream process vessels;

[0044] The physical parameter calibration of the physical parameters of the downstream process container requires recording the volume and shape parameters of the downstream process container, and mathematically modeling the inner cavity of the physical parameters of the downstream process container based on the volume and shape parameters. Since the shape of the downstream process container is non-standardized, the retention volume of the molten metal in the downstream process container needs to be modeled in order to be coupled with the observed quantity.

[0045] a4: laser ranging device parameters;

[0046] The calibration of the laser ranging device mainly completes the calibration of the zero point of the laser ranging device and the physical coordinate system of the downstream process container to ensure that the laser ranging measurement results are in the same coordinate system as the downstream process container.

[0047] a5: Offline calibration parameters;

[0048] By calibrating the downstream process container, laser ranging device and infrared camera, a unified coordinate system for the observed quantity is established, and by measuring the physical parameters of the operating container, the initialization parameters of the control model are completed.

[0049] b: online calculation;

[0050] The online calculation process mainly completes the measurement of the molten metal volume in the downstream process container, and then meets the control speed requirements.

[0051] b1: laser measurement;

[0052] The laser measuring device will shine directly at the surface of the molten metal liquid at a certain angle, measure the distance of the molten metal liquid surface, and then calculate the position of the surface in the downstream process container at this time.

[0053] b2: infrared measurement;

[0054] Infrared measurement is used to locate the liquid surface. Since the surface of the molten metal liquid is not a static page, it is necessary to observe the surface with an infrared camera. The observation results are used to accurately locate and model the molten metal liquid surface through spatial positioning technology and offline calibration parameters.

[0055] b3: Calculation of metal volume in downstream process vessels;

[0056] By combining the observation results in b1 and b2 with the physical parameters in a3, the retained metal volume in the downstream process container can be calculated, and the remaining volume redundancy V1 in the downstream process container can be further calculated.

[0057] b4: Estimation of liquid volume in free state;

[0058] Through the pouring model obtained in a1, the volume outflow of molten metal per unit time can be calculated, and then the volume V2 of free metal liquid in the air that has been poured out of the container and has not reached the downstream process container can be estimated based on the time parameter.

[0059] b5: Calculation of the operating container angle;

[0060] Based on the remaining volume redundancy V1 calculated in b3 and the volume V2 of free liquid metal in the air estimated in b4, the flow transfer device can be modeled, and the upper limit of the dumping volume per unit time, Vt, can be estimated. Combining Vt with the dumping model calculated in a1, the upper limit of the dumping angle, Ang, can be obtained. Since the dumping angle Ang-t at this moment can be obtained by automatically controlling the transfer device, the dumping angle Ang-t' at the next moment can be calculated using methods such as Kalman filtering.

[0061] c.Online control;

[0062] The online control module automatically controls the transfer device through the parameters calibrated offline.

[0063] c1: start dumping;

[0064] The start of dumping is the starting moment of the automatic operation of the entire transfer device, which is generally controlled by humans.

[0065] c2: fixed initialization speed;

[0066] Since all physical parameters of the initial dumping can be obtained from the calibration parameters, the transfer device starts dumping at a fixed speed.

[0067] c3: online speed adjustment;

[0068] According to the operating container angle calculated in real time in b5, the transfer device controls the hydraulic mechanism to automatically adjust the dumping angle.

[0069] c4: Operation completed;

[0070] When the dumping angle is greater than a critical value or the observed volume of the downstream process container is greater than a critical value, the transfer device completes the dumping.

[0071] In summary, the present invention can realize automatic dumping, close the dumping process, and ensure the stability and safety of dumping. At the same time, the present invention can adopt an automated method for observation to avoid the instability of manual observation.

[0072] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for using a transfer device for metal powder processing, characterized in that: Applicable to a transfer device for metal powder processing, the structure of the transfer device for metal powder processing includes: Operating container, infrared camera, laser distance measuring device and downstream process container; The downstream process container is provided with a funnel-shaped opening. The operating container is used to hold the molten metal and pour it into the downstream process container. The molten metal forms a metal retention area at the narrow mouth of the funnel-shaped opening. The laser distance measuring device is used to measure the distance between the metal retention area and the molten metal downstream of the downstream process container. The infrared camera is used to locate the surface of the molten metal liquid downstream. The pouring angle of the operating container is controlled by a closed loop to complete the transfer of the molten metal. A method for using a transfer device for metal powder processing includes the following steps: Step 1: Offline calibration of a working container, an infrared camera, a laser rangefinder, and a downstream process container; establishing a common coordinate system for observations based on the offline parameters of the infrared camera, the laser rangefinder, and the downstream process container; and initializing parameters of the transfer device by measuring physical parameters obtained from the offline calibration of the working container. Step 2: Calculate the volume of molten metal in the downstream process vessel online to obtain the required pouring speed of the operating vessel; Step 3: Perform online control of the transfer device according to the dumping speed requirement of the operating container to complete the dumping of the metal powder; The step 2 of online calculating the volume of metal in the downstream process container in a molten state comprises: Step 2.1: The laser measuring device is directed at a certain angle to the surface of the molten metal liquid, measures the distance to the molten metal liquid surface, and calculates the position of the molten metal liquid surface in the downstream process container at this time; Step 2.2: Observe the surface of the liquid metal using an infrared camera. Use spatial positioning technology and offline calibration parameters to accurately locate and model the molten metal surface and obtain infrared measurement results. Step 2.3: Calculate the retained metal volume in the downstream process container and the remaining volume redundancy V1 in the downstream process container using the measurement results of the laser rangefinder, the infrared measurement results, and the physical parameters of the downstream process container; Step 2.4: Calculate the volume of molten metal outflow per unit time through mathematical modeling of the operating vessel, and estimate the volume V2 of free metal liquid in the air that has been poured out of the vessel and has not reached the downstream process vessel based on time; Step 2.5: Model the flow system based on the remaining volume redundancy V1 and the estimated volume V2 of free liquid metal in the air, and estimate the upper limit Vt of the dumping volume per unit time. Combine Vt with the mathematical modeling of the operating container to calculate the upper limit Ang of the dumping angle, and calculate the dumping angle Ang-t' at the next moment through Kalman filtering.

2. The method for using a transfer device for metal powder processing according to claim 1, characterized in that: The steps for completing the initialization parameters of the transfer device in step 1 include: Step 1.1: Record the volume and shape parameters of the operating container, mathematically model the inner cavity of the operating container based on the volume and shape parameters, obtain the relationship between the pouring angle and the volume of liquid flowing out per unit time, and obtain the physical parameters of the operating container; Step 1.2: Calibrate the infrared camera's internal parameters using a panel with infrared LEDs. Perform spatial calibration between the infrared camera's coordinate system and the physical coordinate system of the downstream process container to complete the infrared camera's external parameter calibration. Step 1.3: Record the volume and shape parameters of the downstream process container, perform mathematical modeling on the inner cavity of the physical parameters of the downstream process container based on the volume and shape parameters, and complete the physical parameter calibration of the downstream process container; Step 1.4: Calibrate the zero point of the laser distance measuring device and the physical coordinate system of the downstream process container to complete the calibration of the laser distance measuring device; Step 1.5: Establish a unified coordinate system for the observed quantities by calibrating the downstream process container, laser rangefinder, and infrared camera. Initialize the parameters of the transfer device by measuring the physical parameters of the operating container.

3. The method for using a transfer device for metal powder processing according to claim 1, characterized in that: The step of performing online control of the transfer device according to the requirement of the dumping speed of the operating container in step 3 includes: Step 3.1: Run the transfer device and automatically control the container to start dumping; Step 3.2: All physical parameters of the initial dumping are obtained through step 1, and the transfer device controls the operating container to start dumping at a fixed speed; Step 3.3: The transfer device controls the hydraulic mechanism to automatically adjust the dumping angle according to the operating container angle calculated in real time in step 2.5; Step 3.4: When the dumping angle is greater than the critical value or the observed volume of the downstream process container is greater than the critical value, the transfer device completes the dumping.

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